March 28, 2017
The effect of lithology on valley width, terrace distribution, and coarse sediment provenance in a tectonically stable catchment with flat-lying stratigraphy
By Amanda Keen-Zebert, Mark Hudson (GECSC), Stephanie Shepherd, and Evan Thaler. Published in Earth Surface Processes and Landforms.
How rock resistance or erodibility affects fluvial landforms is an outstanding question in geomorphology as erosion rates of bedrock channels control the pace of landscape evolution. A reach of the Buffalo National River in Arkansas was partitioned into lithologic reaches and the mechanical and chemical resistance of the main lithologies making up the catchment was measured. The results demonstrate the strong impact that karst dissolution of limestone has had on valley width, terrace distribution, and coarse sediment provenance and therefore, upon landscape evolution processes.
March 17, 2017
Analyzing land-use change scenarios for trade-offs among cultural ecosystem services in the Southern Rocky Mountains
By Ben Sherrouse, Darius Semmens, Zach Ancona, and Nicole Brunner. Published by Ecosystem Services.
U.S. forests, including those of the Southern Rocky Mountains, are projected to see significant increases in outdoor recreation participants by 2060. This will challenge forest managers to balance increasing demand for outdoor recreation with other ecosystem services. Using the GIS tool, Social Values for Ecosystem Services (SolVES), this study analyzed land-use change scenarios based on road-network expansion to quantify changes in aesthetic and recreational ecosystem service values. Trade-offs between these values relative to forest stakeholder groups defined by their attitudes regarding motorized recreation were also assessed. Though trade-off assessments between aesthetic and recreational ecosystem service values indicated that areas of conflicting value changes were limited, the approach this study outlines could be an important means of conflict resolution for multi-use management.
March 10, 2017
Research Ecologists Jenny Briggs and Erin Berryman, Research Geologist Natalie Kehrwald, and Student Volunteer Marianne Blackburn represented the GECSC at a major science education and outreach event titled "Girls & Science" at the Denver Museum of Nature and Science. The event introduced children and families to the work and career paths of female scientists in more than 25 organizations at Federal, State, and local levels. Over 12,000 visitors of all ages and backgrounds attended.
March 8, 2017
Vertebrate paleontology, stratigraphy, and paleohydrology of Tule Springs Fossil Beds National Monument, Nevada (USA)
By Kathleen Springer (GECSC), Jeff Pigati (GECSC), and Eric Scott. Published by Geology of the Intermountain West.
Tule Springs Fossil Beds National Monument preserves 22,650 acres of the upper Las Vegas Wash, and is home to extensive and stratigraphically complex groundwater discharge deposits which represent springs and desert wetlands that covered much of the valley during the late Quaternary. The deposits record hydrologic responses to abrupt climatic oscillations over the last ~300,000 years as well as entomb the Tule Springs Local Fauna, one of the most significant late Pleistocene (Rancholabrean) vertebrate assemblages in the American Southwest. This field compendium highlights the faunal assemblage in the classic stratigraphic sequences of the Las Vegas Formation within the National Monument, emphasizes the significant hydrologic changes that occurred in the area during the recent geologic past, and examines the subsequent and repeated effect of rapid climate change on the local desert wetland ecosystem.
March 3, 2017
Eruptive history, geochronology, and post-eruption structural evolution of the late Eocene Hall Creek Caldera, Toiyabe Range, Nevada
By Joe Colgan (GECSC), and Christopher Henry. USGS Professional Paper 1832.
This report, prepared in cooperation with the Nevada Bureau of Mines and Geology, details the geologic history and extent of the Hall Creek caldera, defines the regional paleotopography at the time it formed, and clarifies the timing and kinematics of post-caldera extensional faulting. Using geologic mapping, argon dating, and geochemical analyses, the examination of this caldera sheds light on its magmatic, tectonic, and topographic evolution.
February 15, 2017
Uranium delivery and uptake in a montane wetland, north-central Colorado, USA
By Randy Schumann (GECSC), Robert Zielinski, Jim Otton, Mike Pantea (GECSC), and William Orem. Published in Applied Geochemistry.
Comprehensive sampling of peat, underlying lakebed sediments, and coexisting waters of a naturally uraniferous montane wetland in north-central Colorado were combined in this study with hydrologic measurements to define the important controls on uranium supply and uptake. The report shows that the major source of uranium to the wetland is groundwater flowing through locally fractured and faulted granite gneiss.
February 14, 2017
Controls on the chemical composition of saline surface crusts and emitted dust from a wet playa in the Mojave Desert (USA)
By Harland Goldstein (GECSC), George Breit, Rich Reynolds (GECSC). Published in the Journal of Arid Environments.
This study determined the compositional controls on atmospheric dust emitted from salt-crusted playas by documenting how variations in the chemical composition of salt crusts and subsurface sediments are related to variations in groundwater composition and evaporative factors. By demonstrating the hydrogeologic and compositional linkages among groundwater, surface crust, and dust, this study provides a basis for understanding the controls on dust composition in evaporative discharge settings in drylands elsewhere. These findings bear on issues of water quality, plant-community distributions, formation and extraction of economic salt deposits, as well as potential risks to human health.
February 13, 2017
DOI/GTN-P Climate and active-layer data acquired in the National Petroleum Reserve-Alaska and the Arctic National Wildlife Refuge, 1998-2015
By Frank Urban and Gary Clow. USGS Data Series 1021.
This report provides data collected by the climate monitoring array of the U.S. Department of the Interior on Federal lands in Arctic Alaska over the period August 1998 to July 2015. In addition to presenting data, this report also describes monitoring, data collection, and quality control methodology. Data collection by the 16 stations in the array is ongoing and done in close collaboration with the Bureau of Land Management and the U.S. Fish and Wildlife Service.
January 12, 2017
On the importance of stratigraphic control for vertebrate fossil sites in Channel Islands National Park, California, USA: Examples from new Mammuthus finds on San Miguel Island
By Jeff Pigati (GECSC), Dan Muhs (GECSC), and Jack McGeehin. Published in Quaternary International.
Mammoth and other quaternary vertebrate fossils are relatively common on the northern Channel Islands, but the lack of geologic context of the finds presented in the published literature has hampered the interpretation of associated 14C ages and reconstruction of past environmental conditions. Fossils (all likely mammoth) were recently uncovered at two sites on the northwest flank of San Miguel Island, and this study presents documentation of their stratigraphic context, descriptions of the host sediments in detail, and their ages. In addition, this report proposes a series of protocols for documenting and reporting geologic and stratigraphic information at fossil sites on the California Channel Islands in general, and in Channel Islands National Park in particular, so that pertinent information is collected prior to excavation of vertebrate materials, thus maximizing their scientific value.
January 6, 2017
Effects of wind energy generation and white-nose syndrome on the viability of the Indiana bat
By Richard Erickson, Wayne Thogmartin, Jay Diffendorfer (GECSC), Robin Russell, and Jennifer Szymanski. Published in PeerJ.
This study employed a spatially explicit full-annual-cycle model to investigate how wind turbine mortality and the infectious fungal disease, white-nose syndrome, may singly and then together affect population dynamics of the endangered Indiana bat. Taken individually, the simulations showed turbine mortality affect local dynamics while white-nose syndrome had a depressive effect on the species across its range. When the model was run with both stressors simultaneously they had a larger impact than would be expected from either alone. The findings illustrate the importance of not only prioritizing the protection of large winter colonies as is currently done, but also of protecting metapopulation dynamics and migratory connectivity. (Icon photo: U.S. Fish and Wildlife Service)
December 30, 2016
GECSC Geologists Jeff Pigati and Kathleen Springer's research on desert wetlands was featured in the Fall 2016 issue of The Oasis, a biannual newsletter of the National Park Service's Mojave Desert Network Inventory and Monitoring Program. The article "Paleohydrology and Changing Climate in Desert Wetlands: Can the past help us predict the future?" explains their research methods as well as what they are trying to learn. Also reported are Jeff and Kathleen's planned data collection activities in the Mojave region for early 2017.
December 14, 2016
Field guide to Laramide basin evolution and drilling activity in North Park and Middle Park, Colorado
By Marieke Dechesne (GECSC), Jim Cole (GECSC), and Christopher Martin. Published in The Mountain Geologist.
This paper highlights the geologic history of the North Park-Middle Park area and its past and recent drilling activity. Written as a fieldguide, basin formation and consequences of the geologic configuration on oil and gas development are discussed, plus a comparison is made with time equivalent strata of the Denver Basin on the other side of the Front Range. Information presented is mostly based on research conducted by the GECSC's Cenozoic Landscape Evolution of the Southern Rocky Mountains Project, previous literature and data from the Colorado Oil and Gas Conservation Commission.
December 8, 2016
Late Quaternary Changes in Lakes, Vegetation, and Climate in the Bonneville Basin Reconstructed from Sediment Cores from Great Salt Lake
By Bob Thompson (GECSC), C.G. Oviatt, Jeff Honke (GECSC), and Jack McGeehin. Chapter 11 of Lake Bonneville—A Scientific Update, published in Developments in Earth Surface Processes.
The reconstruction presented in this chapter is a significant update of our understanding of the climatic and vegetation changes that occurred during the deglacial period in the Bonneville Basin region. Sediment cores taken from the deepest part of Great Salt Lake were used to reconstruct changes in lacustrine environments based on sedimentology, geochemistry, and micropaleontology; and changes in terrestrial vegetation based on pollen analysis. The lacustrine and pollen analysis together show the climate fluctuations that have taken place over the studied area during the last 40,000 years.
December 6, 2016
The primacy of multidecadal to centennial variability over late-Holocene forced change of the Asian Monsoon on the southern Tibetan Plateau
By Jessica Conroy, Adam Hudson (GECSC), Jonathan Overpeck, Kam-Biu Liu, Luo Wang, and Julia Cole. Published in Earth and Planetary Science Letters.
This study examined the sediment record from a closed-basin lake in southern Tibet, Ngamring Tso, along with other published paleoclimatic records to assess summer monsoon precipitation variability over the 20th century and during the late Holocene (4,100 years ago to present). The result is a new monsoon precipitation proxy record that spans millennia but captures the 20th century in high temporal resolution. Through calibrating the 20th century sediment record to local weather station data, the record provides accurate quantitative precipitation estimates for the last four millenia. This calibrated reconstruction of past summer precipitation permits consideration of long term monsoon precipitation variability at timescales meaningful for anticipating future precipitation variability on the southern Tibetan Plateau.
December 2, 2016
Through the multi-agency Palmyra Atoll Research Consortium, a team of six USGS physical scientists, biologists, hydrologists and unmanned aircraft system (UAS) operators, travelled to the Palmyra Atoll in the Pacific Ocean between October 13 and November 3 to collect high resolution aerial data of the flora, fauna and hydrological resources of the Atoll utilizing small UAS with multiple onboard sensors. Joe Adams, a UAS operator from the USGS National Unmanned Aircraft System Project Office, assisted in collecting visible, thermal and multi-spectral data that is being used as proof-of-concept methodology for the development of three-dimensional surface models, vegetation maps, monitoring of sea turtles, manta rays, sharks and other marine and terrestrial biota, as well as to investigate techniques for collecting aerial information to better understand surface and lagoon hydrology while operating in a very remote tropical environment.
November 28, 2016
Defining ecosystem assets for natural capital accounting
By Lars Hein, Ken Bagstad (GECSC), Bram Edens, Carl Obst, Rixt de Jong, and Jan Peter Lesschen. Published in PLOS ONE.
Concepts to understand how ecosystem services are provided and used are often unclear, and are particularly needed to meet emerging standards for natural capital accounting. This paper argues for an expansion of how ecosystem assets are defined, particularly their capacity and capability to supply ecosystem services, as well as the potential supply of ecosystem services. Capacity relates to sustainable use levels of multiple ecosystem services, capability involves prioritizing the use of one ecosystem service over a basket of services, and potential supply considers the ability of ecosystems to generate services regardless of demand for these services. The revised definitions presented here are grounded in the ecosystem services and accounting literature, and illustrate and compare the concepts of flow, capacity, capability, and potential supply with a range of conceptual and real-world examples drawn from case studies in Europe and North America.
November 22, 2016
Probing the volcanic-plutonic connection and the genesis of crystal-rich rhyolite in a deeply dissected supervolcano in the Nevada Great Basin: Source of the late Eocene Caetano Tuff
By Kathryn Watts, David John, Joe Colgan (GECSC), Christopher Henry, Ilya Bindeman, and Axel Schmitt. Published in the Journal of Petrology.
The Caetano caldera in north-central Nevada offers an extraordinarily complete record caldera magmatism exposed in tilted fault blocks that allow direct study of volcanic and plutonic rocks at deep levels within the caldera system. Integrating whole-rock geochemistry, mineral chemistry, isotope geochemistry and geochronology with field studies and geologic mapping, this study defines the petrologic evolution of the magmatic system that sourced the vast Caetano Tuff. This study adds to our understanding how large volumes of silicic magma are assembled and what causes them to erupt as "supervolcanoes."
November 16, 2016
A trans-national monarch butterfly population model and implications for regional conservation priorities
By Karen Oberhauser, Rucsena Wiederholt, Jay Diffendorfer (GECSC), Darius Semmens (GECSC), Leslie Ries, Wayne Thogmartin, Laura López-Hoffman, and Brice Semmens. Published in Ecological Entomology.
The governments of Mexico, Canada, and the United States have agreed to work together to protect the monarch butterfly, a species that has undergone considerable population decline over the past decade. To support planning for continental-scale monarch habitat restoration, this study addresses the question of where efforts are likely to have the largest impacts on the monarch's population growth rate. The model employed suggests that conservation investment in projects across the full monarch range will be more effective than focusing on one or a few regions, and will require international cooperation across many land use categories.
November 8, 2016
Bedrock morphology and structure, upper Santa Cruz Basin, south-central Arizona, with transient electromagnetic survey data
By Mark Bultman and Ric Page (GECSC). USGS Open-File Report 2016-1152.
This report provides an analysis of geophysical data from the Rio Rico and Nogales 1:24,000-scale USGS quadrangles, which includes the city of Nogales, Arizona. The primary objective of this publication is to describe the depth to bedrock, general morphology and structure of the upper Santa Cruz Basin in the study area, and define its relationship to the geohydrology of the region.
November 4, 2016
Improving spatio-temporal benefit transfers for pest control by generalist predators in cotton in the southwestern US
By Ruscena Wiederholt, Ken Bagstad (GECSC), Gary McCracken, Jay Diffendorfer (GECSC), John Loomis, Darius Semmens (GECSC), Amy Russell, Chris Sansone, Kelsie LaSharr, Paul Cryan, Claudia Reynoso, Rodrigo Medellín and Laura López-Hoffman. Published in the International Journal of Biodiversity Science, Ecosystem Services & Management.
This study presents a benefit transfer approach to quantify the economic value of pest control in cotton crops that is provided by a generalist predator, the Mexican free-tailed bat, in the southwestern United States. It is shown that pest-control estimates derived when accounting for key spatial and temporal aspects (such as cotton varieties, crop prices, and pesticide use) are likely to exhibit less error than those derived using simple-spatial or simple-temporal approaches. With the compound spatial-temporal approach, the annualized pest-control value was $12.2 million, in contrast to an estimate of $70.1 million (5.7 times overestimate) obtained from the simple-spatial approach. The report also presents a detailed protocol for valuing pest-control services, which can be used to develop robust pest-control transfer functions for other generalist predators in agroecosystems.
November 3, 2016
A complex origin for the Kelso Dunes, Mojave National Preserve,California, USA: A case study using a simple geochemical method with global applications
By Dan Muhs (GECSC), Nick Lancaster, and Gary Skipp (GECSC). Published in Geomorphology.
The Kelso Dune field contains some of the few active sand dunes in the the Mojave Desert. Although there have been many studies of these dunes, past work has consistently stated that the Kelso Dune field was created primarily from a single source, Mojave River alluvium. There are, however, few data that actually test the Mojave River source of the dunes. In this study, mineralogical and geochemical studies were conducted on dune groups of the Kelso Dune field as well as potential sand sources. Results indicate that the sands in the different dune groups are derived from at least three sources—Mojave River alluvium, Budweiser Wash alluvium, and alluvial fan deposits of the Providence Mountains, showing that even a small dune field can have a complex origin. The article provides examples of large sand seas from Africa and the Middle East with unknown sources, where dune sand origins might be determined with similar geochemical analyses.
November 2, 2016
Geologic framework, age, and lithologic characteristics of the North Park Formation in North Park, north-central Colorado
By Ralph Shroba. USGS Scientific Investigations Report 2016-5126.
This report details the geologic framework, age, and lithologic characteristics of rocks and sediments of late Oligocene and Miocene age locally preserved in and near a large intermontane basin in north-central Colorado. These rocks and sediments once formed a broad and relatively thick sedimentary apron composed chiefly of alluvial-slope deposits. Particle size and sorting data suggest that some of the fine sand, very fine sand, and silt in very fine grained sandstone and siltstone of the North Park Formation may be derived from the erosion of coeval eolian sand and loess in the Browns Park Formation that was transported across the Park Range by westerly or southwesterly winds.
October 28, 2016
Geologic Map of Great Sand Dunes National Park, Colorado
By Rich Madole (GECSC), Paco VanSistine (GECSC), and Joe Romig. USGS Scientific Investigations Map 3362.
This publication was created to provide the public and the National Park Service with a detailed geologic map and information about the age, origin, and evolution of the landscape of which the Great Sand Dunes National Park is a part, as well as to provide support of archeological studies that were initiated by a range fire in 2000. The Park covers an area of 437 square kilometers (or about 169 square miles), of which 98 percent is blanketed by sediment of Quaternary age, making this publication essentially a surficial geologic map. Along with the geologic map and pamplet, the report includes the geodatabase and GIS shape files.
October 21, 2016
GECSC Research Geologist Margaret Berry was interviewed in "The Bridge" blog post Mapping Earth's History with an Eye on the Future. Margaret discusses the societal importance of geologic maps and describes some of the methods, tools, and data sources she uses to create a geologic map. "The Bridge" is a blog published by the American Geophysical Union that focusses on the connection between science and policy, and this story appeared as part of their Earth Science Week series (Friday, Oct. 14, 2016, Geologic Map Day).
October 18, 2016
Expanding the role of reactive transport models in critical zone processes
By Li Li, Kate Maher, Alexis Navarre-Sitchler, Jenny Druhan, Christof Meile, Corey Lawrence (GECSC), and others. Published in Earth-Science Reviews.
Multi-component Reactive Transport Models (RTMs) have been used extensively to explore the interactions of geothermal, hydrologic, geochemical, and geobiological processes in earth's critical zone (the zone that extends from the top of vegetation to the bottom of groundwater). Driven by extensive data sets now available from intensive measurements efforts, there is a pressing need to couple RTMs with other community models to explore non-linear interactions among the atmosphere, hydrosphere, biosphere, and geosphere. This article reviews the history of RTM development, summarizes the current state of RTM approaches, and identifies new research directions, opportunities, and infrastructure needs to broaden the use of RTMs.
October 17, 2016
Pinedale glacial history of the upper Arkansas River valley: New moraine chronologies, modeling results, and geologic mapping
By Avriel Schweinsberg, Jason Briner, Ralph Shroba (GECSC), Joseph Licciardi, Eric Leonard, Keith Brugger, and Charles Russell. Chapter in Unfolding the Geology of the West, Geological Society of America (GSA) Field Guide 44.
This fieldtrip guide for the GSA 2016 Annual Meeting outlines the glacial history of the upper Arkansas River valley, Colorado, and builds on a previous GSA field trip to the area in 2010. The research presented in this publication was stimulated by the Geologic Map of the Granite 7.5' Quadrangle, Lake and Chaffee Counties, Colorado produced by GECSC members Ralph Shroba, Karl Kellogg, and Ted Brandt, in which the mapping of surficial deposits was based chiefly on the interpretation of newly acquired LiDAR data and field investigations. The new
10Be exposure ages generated for the mapped area leads to an improved understanding of the controls and timing of glaciation in the western United States, the modeling of glacial-lake outburst flooding, and the reconstruction of paleotemperature through glacier modeling.
October 12, 2016
Status and trends of land change in the Eastern United States—1973 to 2000 is the fourth and final volume of USGS Professional Paper 1794, with previously published volumes covering the status and trends of land change for other regions of the country. The assessments of land-use and land-cover trends in the report are conducted on an ecoregion-by-ecoregion basis, and each ecoregion assessment is guided by a nationally consistent study design that includes mapping, statistical methods, field studies, and analysis. Two chapters in the report, "Southern Coastal Plain Ecoregion" and "Interior Plateau Ecoregion", are authored by GECSC Geographer Mark Drummond, and GECSC Physical Scientist Mike Stier co-authored (with Beverly Friesen, retired) the chapter "Ridge and Valley Ecoregion".
October 11, 2016
Geomorphic evolution of the San Luis Basin and Rio Grande in southern Colorado and northern New Mexico
By Cal Ruleman (GECSC), Mike Machette, Ren Thompson (GECSC), and Dan Miggins. Chapter in Unfolding the Geology of the West, Geological Society of America Field Guide 44.
The San Luis Basin encompasses the largest structural and hydrologic basin of the Rio Grande rift. This field trip, part of the GSA 2016 Annual Meeting, examines the timing of transition of the San Luis Basin from hydrologically closed, aggrading subbasins to a continuous fluvial system that eroded the basin, formed the Rio Grande gorge, and ultimately, integrated the Rio Grande from Colorado to the Gulf of Mexico.
October 4, 2016
South Park, Colorado: The interplay of tectonics and sedimentation creates one of Colorado's crown jewels
By Peter Barkmann, Ned Sterne, Marieke Dechesne (GECSC), and Karen Houck. Chapter in Unfolding the Geology of the West, Geological Society of America Field Guide 44.
Recent mapping efforts and hydrocarbon exploration in the South Park Basin have brought to light the vast complexity of a structural basin already recognized for its unique sedimentary and tectonic setting. This field trip, part of the GSA Annual Meeting, examines how Paleozoic, Mesozoic, and Cenozoic strata record the tectonic signatures of at least three orogenic episodes in the Basin. The features described at the field trip stops include fold-fault structures, sedimentary basin fill responses through time, and paleogeographic settings.
October 3, 2016
Concentrations of mineral aerosol from desert to plains across the central Rocky Mountains, western United States
By Rich Reynolds (GECSC), Seth Munson, Dan Fernandez, Harland Goldstein (GECSC), and Jason Neff. Published in Aeolian Research.
USGS researchers and colleagues analyzed a four-year record of total dust (TSP) deposition across part of the interior American West. Their results revealed extraordinarily high TSP mass concentrations, which consistently and greatly exceeded co-sampled measures of dust particles less than 10 micrometers (PM10) that are used nationally and globally to evaluate air quality for health and visibility issues. This study showed that TSP was derived primarily from regional dust sources and that PM10 measurements are inadequate for measuring regional air quality.
September 23, 2016
Quaternary geologic map of the Wolf Point 1° × 2° quadrangle, Montana and North Dakota
By Dave Fullerton (GECSC), Roger Colton, and Chuck Bush (GECSC). USGS Open-File Report 2016-1142.
This 1:250,000-scale map of an area of northern Montana and North Dakota was prepared to provide a database for compilation of the Regina 4° x 6° 1:1,000,000-scale quadrangle, part of the USGS Quaternary Geologic Atlas of the United States map series. Surficial deposits and materials shown on the map are assigned to 23 map units on the basis of genesis, age, lithology or composition, texture or particle size, as well as other physical, chemical, and engineering characteristics, and generally not indicative of landforms. Along with the geologic map, the report includes the geodatabase and GIS shape files.
September 16, 2016
Evaluating alternative methods for biophysical and cultural biophysically modeled hotspot mapping in natural resource planning
By Ken Bagstad, Darius Semmens, Zach Ancona, and Ben Sherrouse. Published in the Landscape Ecology.
While biophysical models of increasing sophistication are helping resource managers systematize ecosystem service assessments, cultural ecosystem services have not been as well integrated into many assessments. Using six hot/coldspot delineation methods, this study overlaid biophysically modeled ecosystem services mapped using the ARIES modeling software with cultural services mapped using Social Values for Ecosystem Services (SolVES), a public participatory GIS approach, for six national forests in Colorado and Wyoming. Statistical hotspot methods of intermediate conservatism may be most useful for landscape scale planning that incorporates ecosystem service hot/coldspot mapping. The study also found evaluated ecosystem service hot and coldspots in wilderness areas. Wilderness areas to carried greater values than non-wilderness for national forests located near urban areas, but were less valued than non-wilderness areas in rural areas.
September 16, 2016
Research geologist Dan Muhs was quoted by CNN in their article Tale of the tusks: Discovery of intact mammoth skull raises questions. A mammoth skull found on Santa Rosa Island, part of Channel Islands National Park off the coast of California, is estimated to be 13,000 years old, which would place it at about the time as the earliest human records on the island. Dan offers some possibilities of how mammoths became extinct on the Channel Islands, which include human activities compounded with stresses related to climate change.
September 12, 2016
Toward an integrated understanding of perceived biodiversity values and environmental conditions in a national park
By Carena van Riper, Gerard Kyle, Ben Sherrouse (GECSC), Ken Bagstad (GECSC), and Stephen Sutton. Published in Ecological Indicators.
Drawing on a spatially explicit participatory mapping exercise and a Social Values for Ecosystem Services (SolVES) analysis tool, this study empirically examined and integrated social values for ecosystem services and environmental conditions within Channel Islands National Park, California. It was found that factors like knowledge of the Channels Islands, as well as accessibility and infrastructure within the park effect how and where people valued its protected land and seascapes. Given that social value indicators are sometimes sidelined in decision-making, this study elevates the importance of these metrics to support the spatial prioritization of conservation and provide insight into how social and ecological data can be blended to inform natural resource management decisions.
September 6, 2016
Holocene paleoclimate inferred from salinity histories of adjacent lakes in southwestern Sicily (Italy)
By Brandon Curry, Paul Henne (GECSC), Francesc Mezquita-Joanes, Federico Marrone, Valentina Pieri, Tommaso La Mantia, Camilla Calò, and Willy Tinner. Published in Quaternary Science Reviews.
How moisture availability changed in the central Mediterranean region during the Holocene remains uncertain, which complicates understanding how past climatic changes affected Mediterranean ecosystems and societies. New paleosalinity reconstructions, inferred from ostracodes preserved in the sediments of two lakes in coastal Sicily, Italy indicate contrasting changes; salinity increased markedly at Lago Preola during the Holocene, but was lowest at nearby Gorgo Basso during the late Holocene. Whereas rising sea levels brought an influx of seawater that increased salinity at Lago Preola, climate was the dominant driver of salinity changes at Gorgo Basso. Low salinity during the late Holocene at Gorgo Basso suggests an increase in moisture availability, and supports the conclusion that important ecological changes during that last 3000 years, such as the disappearance of coastal forests were caused by human activity, not a drying climate.
August 31, 2016
Chemical abrasion-SIMS (CA-SIMS) U-Pb dating of zircon from the late Eocene Caetano caldera, Nevada
By Kathryn Watts, Matthew Coble, Jorge Vazquez, Christopher Henry, Joe Colgan (GECSC), and David John. Published in Chemical Geology.
Upon crystallization, zircon (a nearly ubiquitous mineral in felsic igneous rocks) incorporates uranium from its host magma, while strongly excluding lead. It thus provides a robust record of radiogenic lead accumulation from uranium decay—unless lead is "lost" from the zircon after it forms. To mitigate lead loss, chemical abrasion can be used to dissolve away damaged parts of the zircon grain. This is widely done in conjunction with thermal ionization mass spectrometry (in which the whole zircon is dissolved) but this study is the first to employ it in conjunction with secondary ion mass spectrometry (in which a small spot on the zircon is selected for dating). Results indicate that lead loss can affect zircons as young as 34 Ma, and that chemical abrasion can partly, although not completely, mitigate the problem.
August 19, 2016
Total belowground carbon flux in subalpine forests is related to leaf area index, soil nitrogen, and tree height
By Erin Berryman (GECSC), Michael Ryan, John Bradford, Todd Hawbaker (GECSC), and Richard Birdsey. Published in Ecosphere.
In forests, total belowground carbon flux is a large component of the carbon budget and represents a critical pathway for delivery of plant carbon to soil. This study looked for predictable patterns of total belowground carbon flux with measured variability in leaf area index, soil nitrogen, and tree height across three different subalpine forests in the Rocky Mountains. The results, which varied in support among the relationships studied, can aid with estimates of forest soil respiration and total belowground carbon flux across landscapes, using spatially explicit forest data such as national inventories or remotely sensed data products.
August 16, 2016
GECSC Geologist Natalie Kehrwald was invited by the National Academy of Sciences to present her work on melting glaciers to Hollywood writers and directors as part of the Science & Entertainment Exchange. The goal of this exchange is to incorporate accurate science into entertainment media and to show the wonder and adventure of science in narratives. Natalie discussed her work with Adventurers and Scientists for Conservation, a nonprofit organization that recruits members of the outdoor adventure community to help gather data.
August 12, 2016
Iron oxide minerals in dust-source sediments from the Bodélé Depression, Chad: Implications for radiative properties and Fe bioavailability of dust plumes from the Sahara
By Bruce Moskowitz, Rich Reynolds (GECSC), Harland Goldstein (GECSC), Thelma Berquó, Raymond Kokaly, and Charlie Bristow. Published in Aeolian Research.
Researchers, including Scientist Emeritus Rich Reynolds and Geologist Harland Goldstein from the GECSC, examined dust-source sediments from the Bodélé Depression, central Chad, for their iron minerals. The Bodélé Depression has been a significant global dust source during most of the Holocene and perhaps during past interglacial stages. Because of the remote location of the Bodélé Depression, dusts from it are free from human influence, either by land disturbance or contaminants. Therefore, the generation and composition of Bodélé dust today provide a window into the emission and composition of dust in the past and into the effects of this dust on paleoclimates. This study discovered nano-size iron minerals in dust generated from the most prolific dust-producing area in the world that can affect both atmospheric dynamics and ocean fertilization with consequent draw-down of atmospheric carbon dioxide.
August 11, 2016
Hydrogeologic investigations of the Miocene Nogales Formation in the Nogales area, upper Santa Cruz basin, Arizona
By Ric Page (GECSC), Floyd Gray, Mark Bultman, and Chris Menges. USGS Scientific Investigations Report 2016-5087.
This report presents hydrogeologic investigations that were conducted to better understand and evaluate the groundwater resource potential of the Nogales Formation in the Nogales, Arizona, area. Results obtained through geologic mapping and geophysical modeling of the Rio Rico and Nogales 7.5' quadrangles suggest that parts of the Miocene Nogales Formation may be new, deeper sources of groundwater for the area.
August 9, 2016
A 3-dimensional fly-through created by GECSC Cartographer Ted Brandt won first place in the ArcGIS Pro map category at the 2016 ESRI International Users Conference. The entry consisted of the 3D video project and the Geologic map of the Alamosa 30' × 60' quadrangle (USGS Scientific Investigations Map 3342).
August 3, 2016
The new Paleohydrology of Desert Wetlands website presents an overview of research conducted by the GECSC and collaborators that examines how springs and wetlands responded to abrupt climate change during the recent geologic past. Desert wetlands are among the most biologically diverse ecosystems in the world, but our knowledge and understanding of them is extremely limited. By examining deposits associated with wetlands in the geologic record, the Project will inform conservation efforts aimed at protecting present-day desert wetlands in light of future climate warming.
August 2, 2016
As part of the continued implementation of the President's Climate Action Plan, the National Oceanic and Atmospheric Administration has released an updated version of the Climate Explorer, which is an accessible decision-support tool for navigating climate projection information. The application visualizes future climate projections through maps and charts at a county level for the Contiguous United States. GECSC Physical Scientist Jay Alder and USGS collaborator David Blodgett aided in the development of the Climate Explorer through their expertise in climate model visualization and spatial analysis of the data sets that underpin the application.
July 20, 2016
Fluvial system response to late Pleistocene-Holocene sea-level change on Santa Rosa Island, Channel Islands National Park, California
By Randy Schumann (GECSC), Jeff Pigati (GECSC), and Jack McGeehin. Published in Geomorphology.
Alluvial deposits on Santa Rosa Island record responses to more than 100 meters change in sea level from the most recent glacial to our modern interglacial period. Alluvium initially accumulated on the exposed marine shelf, then sedimentation progressed upstream. Driven by rising sea level, the valleys eventually accumulated as much as 14 m of fine-grained sediment, which have since been incised to form deep arroyos.
July 15, 2016
The GECSC's Sources, compositions, and effects of atmospheric dust from American Drylands Project presents the Dust Event Detection Website. The project maintains a catalog of satellite imagery that captures dust-emission events in the western United States, and this new website makes that information accessible. Although the catalog has broad applicability, it primarily complements ongoing work focusing on the effects of dust deposited on mountain snow cover.
July 12, 2016
Geologic map of the Murray quadrangle, Newton County, Arkansas
By Mark Hudson and Kenzie Turner. USGS Scientific Investigations Map 3360.
Created in cooperation with the National Park Service, this map summarizes the stratigraphy and structural geology of the Murray quadrangle in the Ozark Plateaus region of northern Arkansas that includes a portion of Buffalo National River. Included with the 1:24,000-scale map are supporting GIS files.
June 30, 2016
First records of Canis dirus and Smilodon fatalis from the late Pleistocene Tule Springs local fauna, upper Las Vegas Wash, Nevada
By Eric Scott and Kathleen Springer (GECSC). Published in PeerJ.
The Tule Springs local fauna is the largest open-site vertebrate fossil assemblage dating to the Rancholabrean North American Land Mammal Age in the southern Great Basin and Mojave Desert, with over 600 discrete body fossil localities recorded. The recovered fauna is dominated by remains of extinct camels, mammoths, horses, bison, and only rarely large carnivorans, such as cougars and American lion. Among the carnivorans, fossils of Canis dirus (dire wolf) provide the first evidence of its existence in Nevada, and the remains of Smilodon fatalis (sabre-toothed cat) are the only known occurrence of that species in southern Nevada.
June 27, 2016
A regional record of expanded Holocene wetlands and prehistoric human occupation from paleowetland deposits of the western Yarlung Tsangpo valley, southern Tibetan Plateau
By Adam Hudson (GECSC), John Olsen, Jay Quade, Guoliang Lei, Tyler Huth, and Hucai Zhang. Published in Quaternary Research.
This article presents a record of Holocene hydrologic variability in a Tibetan Plateau valley based on sedimentology and 14C dating of organic-rich 'black mats' in paleowetlands deposits. Wetland changes in the record correlate with monsoon intensity changes identified in nearby records, indicating peak wetness during the early Holocene, declining towards the present, and with weak monsoon intervals corresponding to desiccation and erosion of wetlands. Dating of in situ ceramic and microlithic artifacts within the wetlands indicates widespread colonization of the Plateau in the early and mid-Holocene during warm, wet post-glacial conditions.
June 23, 2016
A management-oriented framework for selecting metrics used to assess habitat- and path-specific quality in spatially structured populations
By Sam Nicol, Ruscena Wiederholt, Jay Diffendorfer (GECSC), Brady Mattsson, Wayne Thogmartin, Darius Semmens (GECSC), Laura López-Hoffman, and Ryan Norris. Published in Ecological Indicators.
One of the key questions for most decision makers interested in managing spatially structured populations (those that occupy two or more distinct habitats that are connected by the regular movement of individuals) is which habitats or connections between habitats should be managed or protected to maximize the benefit to the population as a whole? Given the many metrics developed for spatially structured models, it can be challenging to select the most appropriate one for a particular decision. To guide the management of spatially structured populations, this study developed a framework to help managers with problem framing, choosing metrics of habitat and pathway quality, and to elucidate the data needs for a particular metric.
June 20, 2016
Holocene evolution of diatom and silicoflagellate paleoceanography in Slocum Arm, a fjord in southeastern Alaska
By John Barron, John Bukry, Jason Addison, and Tom Ager (GECSC). Published in Marine Micropaleontology.
This study presents diatom and silicoflagellate assemblages constructed from offshore cores that reveal the paleoclimatic and paleoceanographic evolution of the eastern margin of the Gulf of Alaska during the past 10,000 years. GECSC Scientist Emeritus Tom Ager participated in the oceanographic cruise that collected the analyzed core and provided the initial description and samples for accelerator mass spectrometry 14C dating.
June 17, 2016
Geologic and geophysical models for Osage County, Oklahoma, and implications for groundwater resources
By Mark Hudson (GECSC), David Smith, Mike Pantea, and Carol Becker. USGS Scientific Investigations Report 2016-5067.
This report summarizes a three-dimensional geologic model that was constructed to provide a framework to investigate groundwater resources of the Osage Nation in northeastern Oklahoma. It also presents an analysis of an airborne electromagnetic survey that assessed the spatial variation of electrical resistivity to depths as great as 300 meters in the subsurface. The report and model provide support for a countywide assessment of groundwater resources, emphasizing the Upper Pennsylvanian rock units in the shallow subsurface of central and eastern Osage County having electrical resistivity properties that may indicate aquifers. The report highlights westward-inclined, high-resistivity bodies centered on several sandstone-rich layers that extend as much as 10 km down the dip of host strata that are a proxy for potential freshwater aquifers.
June 15, 2016
Forest disturbance interactions and successional pathways in the Southern Rocky Mountains
By Lu Liang, Todd Hawbaker (GECSC), Zhiliang Zhu, Xuecao Li, Peng Gong. Published in Forest Ecology and Management.
By examining a 13-year time series of Landsat image stacks, this study was able to compare the effects of various types of compounded disturbances on lodgepole pine forest regeneration with singular disturbances and assess the link between mountain pine beetle outbreaks and wildfires. It was found that burn severity was largely unrelated to the severity of pre-fire beetle outbreaks in the study area, where the severity of post-fire beetle outbreaks generally decreased in relation to burn severity. Pre-fire beetle outbreaks and subsequent fire produced positive compound effects on seedling reestablishment in this ecoregion.
June 9, 2016
Geologic map of the Panguitch 30' x 60' quadrangle, Garfield, Iron, and Kane Counties, Utah
By Robert Biek, Pete Rowley, John Anderson, Florian Maldonado (GECSC), Dave Moore (GECSC), David Hacker, Jeffrey Eaton, Richard Hereford, Edward Sable, Harry Filkorn, and Basia Matyjasik. Utah Geological Survey Map 2700M.
Winner of the 2016 Mankin Memorial Award, this 1:62,500 geologic map covers an area in southwestern Utah that includes Bryce Canyon National Park and Cedar Breaks National Monument. Described here are diverse geologic features that include flatter Colorado Plateau to the east, highly extended Basin and Range Province to the west, as well as Marysvale volcanic field structure and stratigraphy. This DVD publication includes map plates, report, and GIS data.
June 8, 2016
GECSC Geologist Kathleen Springer was featured in the KCET Los Angeles article "The SoCal Ice Age Fossil Treasure Trove You've Never Heard Of". It tells the story of the Diamond Valley Lake reservoir construction project which unearthed over 100,000 fossil specimens that included bones of mammoths, mastodon, bison, sloths, and horses. Kathleen was working at the San Bernardino County Museum when the discovery was made in 1993, and the article details how she became involved with the massive excavation and her experience there.
May 24, 2016
The Point Sal-Point Piedras Blancas correlation and the problem of slip on the San Gregorio-Hosgri fault, central California Coast Ranges
By Joe Colgan (GECSC) and Richard Stanley. Published in Geosphere.
To better understand right lateral slip on the San Gregorio-Hosgri fault, this study collected stratigraphic and detrital zircon data from Miocene strata at Point Sal and Point Piedras Blancas along the central California coast. The goal was to determine if these sections contained unique characteristics that could establish how far apart they were in the early Miocene, and thus how much of their current separation could be attributed to fault slip. No unique characteristics in the stratigraphy and provenance of the sampled sections were found, but the data did establish the maximum depositional age of the previously undated Point Piedras Blancas section, and demonstrated the utility of trace-element data for discriminating between zircons of oceanic crust and arc affinity.
May 17, 2016
Geologic map of the Rio Rico and Nogales 7.5' quadrangles, Santa Cruz County, Arizona
By Ric Page (GECSC), Chris Menges, Floyd Gray, Margaret Berry (GECSC), Mark Bultman, Mike Cosca, and Paco VanSistine (GECSC). USGS Scientific Investigations Map 3354.
This 1:24,000-scale geologic map covers quadrangles located in the Basin and Range Province of southern-most Arizona and includes the binational urban area of Nogales Arizona (U.S.) and Sonora (Mexico). The mapping was undertaken to define the geologic framework for the Nogales area and the upper Santa Cruz basin to support ongoing multidisciplinary projects as well as to better assess the area's groundwater resource potential. Along with the map, pamphlet and combined 40Ar/39Ar data, downloadable GIS files are included with this publication.
May 12, 2016
The road to Yucca Mountain—evolution of nuclear waste disposal in the United States
By John Stuckless (GECSC) and Robert Levitch. Published in Environmental & Engineering Geoscience.
This report, by GECSC Scientist Emeritus John Stuckless and Robert Levitch (Dept. of Energy, retired), summarizes the process of selecting a site and method for the disposal of spent nuclear fuel and high-level radioactive waste. After more than 30 years of debate, the process lead to the selection of Yucca Mountain, Nevada and a deep underground repository. Yucca Mountain and the surrounding area were then studied for more than 30 years as described in more than 100 detailed study plans that covered a broad spectrum of earth-science. The work, which cost more than 10 billion dollars and required hundreds of man-years, culminated in a license application submitted to the U.S. Nuclear Regulatory Commission in 2008.
April 28, 2016
GECSC Geologist Dan Muhs is quoted in the New York Times opinion piece "Lessons From Underwater Miami" by Peter Brannan. The article focuses on the Eemian Interglacial Period, a time on Earth (about 130,000-115,000 years ago) that was slightly warmer than present but that experienced drastically higher sea levels. An explanation of the example mentioned in the article of how fossil coral in downtown Miami provides evidence of potential higher sea levels can be found in the Geologic Records of High Sea Levels Project website.
April 26, 2016
The new Geologic Records of High Sea Levels Project website gives an overview of research headed by the GECSC that looks to better our understanding of how coastlines or marine terraces preserve records of past high sea levels. Knowledge of past high sea levels is important due to the implications of sea level rise due to loss of major ice sheets because of future climate change. The research from this project attempts to answer questions about the timing of past interglacial sea-level high stands, magnitudes of past interglacial high-sea stands, rates of sea level rise, and marine paleotemperatures.
April 6, 2016
Social-value maps for Arapaho, Roosevelt, Medicine Bow, Routt, and White River National Forests, Colorado and Wyoming
By Zach Ancona, Darius Semmens, and Ben Sherrouse. USGS Scientific Investigations Report 2016-5019.
Assessments of ecosystem goods and services notably lack information describing the spatial distribution and relative intensity of social values, which are the perceived, nonmarket values derived particularly from cultural ecosystem services. This study used the GIS tool SolVES to identify the location and relative intensity of social values as derived from survey responses gathered from residents living in counties adjacent to five National Forests located near rapidly growing urban areas in the southern Rocky Mountain region. The resulting maps and data presented in this report represent the first publicly available spatial data on social-value intensity for this area.
April 5, 2016
Geochemical evidence for seasonal controls on the transportation of Holocene loess, Matanuska Valley, southern Alaska, USA
By Dan Muhs (GECSC), Jim Budahn (GECSC), Gary Skipp (GECSC), and Jack McGeehin. Published in Aeolian Research.
Loess is a widespread Quaternary deposit in the Matanuska Valley of southern Alaska, but determining its source has been problematic. This study presents new stratigraphic, mineralogical, and geochemical information that demonstrates that silt from the Matanuska River is the likely source of loess. The significance of this is that most loess accumulation probably takes place in autumn rather than summer. These findings could be applicable to understanding seasonal controls on Pleistocene loess accretion in Europe, New Zealand, South America, and elsewhere in North America.
March 31, 2016
Quasi-extinction risk and population targets for the Eastern, migratory population of monarch butterflies (Danaus plexippus)
By Brice Semmens, Darius Semmens (GECSC), Wayne Thogmartin, Ruscena Wiederholt, Laura López-Hoffman, Jay Diffendorfer (GECSC), John Pleasants, Karen Oberhauser, and Orley Taylor. Published in Scientific Reports.
Given the cultural significance of monarch butterflies and their general downward population trend, it is important to establish the extent of this species' vulnerability and identify the population size needed to reduce the risk of quasi-extinction to an acceptable level. Quasi-extinction occurs when the population size drops to the point at which recovery is no longer possible. This study's model found that, given a range of plausible quasi-extinction thresholds, the monarch population has a substantial probability of quasi-extinction, from 11-57% over 20 years. The report also suggests an approximately 5-fold increase of the monarch population size (relative to the winter of 2014-15) is necessary to halve the current risk of quasi-extinction across all thresholds considered.
March 29, 2016
Geologic history of the Black Hills caves, South Dakota
By Art Palmer, Peggy Palmer, and Jim Paces (GECSC). Published in GSA Special Paper 516, Caves and Karst Across Time.
This report describes the complex history of cave development in the Madison aquifer of the Black Hills of South Dakota. The region contains many significant caves (including those found in Jewel Cave National Monument and Wind Cave National Park) whose geology and origin have been scrutinized for decades by various researchers. Nevertheless, many aspects of speleogenesis remain controversial. This chapter compares viewpoints and presents evidence for a multistage origin of the Black Hills caves that extends over more than 300 million years. Interpretations are based on decades of work by Art and Peggy Palmer. GECSC Geologist Jim Paces contributed recent isotopic and geochronologic data on the most recent episode of phreatic calcite deposition recording fluctuations in water table elevations over the last 300,000 years.
March 28, 2016
Prioritizing Avian Species for Their Risk of Population-Level Consequences from Wind Energy Development
By Julie Beston (GECSC), Jay Diffendorfer (GECSC), Scott Loss, and Douglas Johnson. Published in PLoS ONE.
This study presents a prioritization system to identify the avian species most likely to experience population declines from wind facilities based on their current conservation status and their expected risk from turbines. The study developed three metrics of turbine risk that incorporate data on collision fatalities at wind facilities, population size, life history, species' distributions relative to turbine locations, number of suitable habitat types, and species' conservation status. It is shown that several birds of prey, such as the long-eared owl, ferruginous hawk, Swainson's hawk, and golden eagle, are at relatively high risk of population decline across a wide variety of cutoff values, whereas many passerines are at relatively low risk of decline.
March 21, 2016
Modeling the effects of urban expansion on natural capital stocks and ecosystem service flows: A case study in the Puget Sound, Washington, USA
By Ben Zank, Ken Bagstad (GECSC), Brian Voigt, and Ferdinando Villa. Published in
Landscape and Urban Planning.
The growth of cities is a major driver of global and regional environmental change and is shifting patterns of ecosystem services provision and society's dependence on them. To better understand how urban expansion effects natural capital stocks and ecosystem service flows, this study modeled the effects of two alternative land use-change development scenarios in the Puget Sound region using the ARIES platform. While natural capital stocks declined under managed and unmanaged development scenarios, ecosystem service flows increased. Human development of natural landscapes reduced their capacity for service provision, while simultaneously adding beneficiaries, increasing ecosystem service flows particularly along the urban fringe.
March 7, 2016
DOI/GTN-P Climate and Active-Layer Data Acquired in the National Petroleum Reserve–Alaska and the Arctic National Wildlife Refuge, 1998-2014
By Frank Urban and Gary Clow. USGS Data Series 977.
This report (which supersedes USGS Data Series 892) provides data collected by the climate monitoring array of the U.S. Department of the Interior on Federal lands in Arctic Alaska over the period August 1998 to July 2014. In addition to presenting data, this report also describes monitoring, data collection, and quality control methodology. The data collection is ongoing and done in close collaboration with the Bureau of Land Management and the U.S. Fish and Wildlife Service.
March 2, 2016
Structured Heterogeneity in a Marine Terrace Chronosequence: Upland Mottling
By Marjorie Schulz, Dave Stonestrom, Corey Lawrence (GECSC), Tom Bullen, John Fitzpatrick, Emily Kyker-Snowman, Jane Manning, and Meagan Mnich. Published in Vadose Zone Journal.
Soil mottles reflect the spatial heterogeneity of soil development and are generally interpreted as products of reducing conditions during periods of water saturation. The presence of mottles in well-drained soils of the Santa Cruz Marine Terraces suggests other processes can also lead to the formation of these features. To explore how a presumably wetland feature occurs in an unsaturated upland soil, physical and chemical characteristics of mottle separates were compared in a chronosequence of soil development. The results of this study suggest that reticulate mottling may form on old, stable land forms as the long-term imprint of rhizospheric processes that regulate soil weathering, nutrient availability, and carbon sequestration at depth.
February 26, 2016
A decision framework for identifying models to estimate forest ecosystem services gains from restoration
By Zachary Christin, Ken Bagstad (GECSC), and Michael Verdone. Published in Forest Ecosystems.
Restoring degraded forests and agricultural lands has become a global conservation priority, but in order to quantify ecosystem service tradeoffs associated with restoration, practitioners must select from a growing number of ecosystem service tools. This article presents the Restoration Ecosystem Service Tool Selector (RESTS), an adaptable framework that describes and filters 13 available tools. RESTS can guide decision makers towards appropriate tools that meet their selected criteria.
February 24, 2016
Testing the Hydrologic Utility of Geologic Frameworks
By Benjamin Mirus, Keith Halford, Don Sweetkind (GECSC), and Joe Fenelon. Published in Hydrogeology Journal.
This article presents a novel method for evaluating assumed relations between hydraulic conductivity and geologic interpretations for regional-scale groundwater modeling. Using Pahute Mesa (an area within the Nevada National Security Site) as a test location, it is shown how the hydrologic utility of geologic frameworks can be evaluated directly with aquifer-test results and geologic observations. GECSC Geologist Don Sweetkind contributed subsurface hydrogeologic framework to the analysis.
February 23, 2016
Stratigraphic architecture of a fluvial-lacustrine basin-fill succession at Desolation Canyon, Uinta basin, Utah: Implications for Walthers' Law and the petroleum industry
By Grace Ford, David Pyles, and Marieke Dechesne (GECSC). Published in The Mountain Geologist.
New insights in Uinta Basin stratigraphy and regional-scale interpretations for the Paleogene fluvial and lacustrine Wasatch and Green River formations in Desolation Canyon, Utah subdivide the fluvial Wasatch Formation into three large-scale lithostratigraphic units. The high net-sand content middle Wasatch shows an abrupt facies shift that does not appear genetically linked with the lower net-sand content upper and lower units. Other facies transitions between the Wasatch and Green River are more gradational and follow Walther's Law. The abrupt change in fluvial style within the Wasatch could be related to drastic changes in climate around the Paleocene-Eocene boundary.
February 18, 2016
Mountains, glaciers, and mines—The geological story of the Blue River valley, Colorado, and its surrounding mountains
By Karl Kellogg, Bruce Bryant, and Ralph Shroba. USGS Circular 1400.
This report describes, in a nontechnical style, the geologic history and mining activity in the Blue River region of Colorado, which includes all of Summit County. The geology of this region is defined by episodes of uplift, sedimentation, rifting, volcanism, and glaciation, which has led to the valley's current configuration and historical significance.
January 19, 2016
Lake oxygen isotopes as recorders of North American Rocky Mountain hydroclimate: Holocene patterns and variability at multi-decadal to millennial time scales
By Lesleigh Anderson (GECSC), Max Berkelhammer, John Barron, Byron Steinman, Bruce Finney, and Mark Abbott. Published in Global and Planetary Change.
One of the pressing questions about the hydroclimate of the North American west is the role of Pacific ocean-atmosphere modes such as El Niño and La Niña. This is a difficult question for global climate models to address whereas there is abundant evidence from paleorecords based on lake sediment oxygen isotopes. This invited review article presents an overview of 18 lake sediment oxygen isotope records along with a new compilation of lake water isotopes that are used to characterize lake sediment sensitivity to precipitation. The study of these records indicate that further investigation of precipitation patterns on short (observational) and long (Holocene) time scales is needed to improve understanding of the processes that drive regional precipitation responses to Pacific ocean-atmosphere variability, which in turn, will lead to a better understanding of internal Pacific ocean-atmosphere variability and its response to external climate forcing mechanisms.
January 7, 2016
Desert Wetlands—Archives of a Wetter Past
By Jeff Pigati (GECSC), Kathleen Springer (GECSC), and Craig Manker. USGS Factsheet 2015-3077.
Once thought of as stagnant and unchanging, new evidence suggests that springs and wetlands in the Las Vegas Valley of southern Nevada responded dynamically to past episodes of abrupt climate change. GECSC scientists are now studying wetland deposits throughout the arid American Southwest to determine how closely conditions in the desert were tied to regional and global climate patterns in the past, and what it might mean for the fragile ecosystems in light of anticipated climate change in the future. This Factsheet gives a brief overview of this research and presents some of the latest findings.
January 5, 2016
Evaluating connection of aquifers to springs and streams, Great Basin National Park and vicinity, Nevada
By David Prudic, Don Sweetkind (GECSC), Tracie Jackson, Elaine Dotson, Russell Plume, Christine Hatch, and Keith Halford. USGS Professional Paper 1819.
This report presents results of a four-year study (2008-2012) conducted by scientists from the USGS and the University of Nevada, Reno to improve understanding of and connections between surface water and groundwater hydrologic systems in the vicinity of Great Basin National Park. Proposed groundwater withdrawals in Snake Valley, Nevada potentially threaten streams and spring-discharge areas in and adjacent to the Park and numerous water-dependent ecosystems on Federal lands in Snake Valley, Nevada. This report presents findings that detail the interaction of these hydrologic systems based on comprehensive geologic, hydrologic, and geochemical studies.
December 29, 2015
South Central Plains Ecoregion
By Mark Drummond. Chapter 17 of Status and Trends of Land Change in the Midwest-South Central United States—1973 to 2000, USGS Professional Paper 1794-C.
Geographer Mark Drummond's chapter of this report gives an overview of the United States' South Central Plains ecoregion which covers the western margin of the southern pine-forest belt of southern Arkansas, northern and western Louisiana, southeastern Oklahoma, and eastern Texas. Changes in the extent of land cover from 1973 to 2000 are also detailed, which include cycles of forest harvest and regrowth, as well as conversions from agriculture to grassland/shrubland and forest, in addition to urbanization and mining. USGS Professional Paper 1794-C is the third in a four-volume series on the status and trends of the Nation's land use and land cover that together with field photographs, statistics, and comparisons with other assessments present brief summaries of the patterns and rates of land change observed in each ecoregion of the study area.
December 28, 2015
Water Isotope Systematics
Quaternary Science Reviews Volume 131, Part B, edited by Matthew Jones, Andy Baker, Lesleigh Anderson (GECSC), and Sylvia Dee.
GECSC Geologist Lesleigh Anderson co-edited this volume of Quaternary Science Reviews that collects 11 studies on Water Isotope Systematics. The volume covers such topics as the understanding sub-GNIP scale variability in isotopes in precipitation from different regions, detailed examination of the transfer of isotope signals from precipitation to geological archives, and the implications of advances in understanding in these areas for the interpretation of palaeo records and proxy data-climate model comparison. Included in the volume are Water isotope systematics: Improving our palaeoclimate interpretations, co-authored by Lesleigh, and Isotopes in North American Rocky Mountain Snowpack 1993-2014, of which she is first author.
December 14, 2015
Dynamic response of desert wetlands to abrupt climate change
By Kathleen Springer (GECSC), Craig Manker, and Jeff Pigati (GECSC). Published by PNAS.
The paleohydrologic record from the Las Vegas Valley of Nevada presented in this article shows cycles of wetland expansion and contraction during the past 35,000 years that correlate tightly with climatic oscillations recorded in Greenland ice cores. Shown are multiple rapid warming events in the record that correspond with the collapsing of entire Las Vegas Valley wetland systems, with drought-like conditions lasting for a few hundred years. Lead author Kathleen Springer was interviewed about the report on the BYU Radio program Top Of Mind With Julie Rose as well as in The Environmental Monitor journal.
December 10, 2015
Quantifying soil carbon loss and uncertainty from a peatland wildfire using multi-temporal LiDAR
By A.D. Reddy, Todd Hawbaker (GECSC), F. Wurster, Z. Zhu, S. Ward, D. Newcomb, and R. Murray. Published in Remote Sensing of Environment.
Peatlands are a major reservoir of global soil carbon, but human activities like draining can hinder their ability to sequester carbon and expose their soils to fire under dry conditions. This study used multi-temporal LiDAR to obtain pre- and post-fire elevations to estimate soil carbon loss caused by a 2011 fire in Great Dismal Swamp National Wildlife Refuge. In comparison with burned areas of other larger fires, the carbon loss on a per unit-area basis was greater at this study location. This finding suggests that previous studies underestimated carbon loss or the severity of the soil carbon loss from the studied fire was unlike many previously studied peatland fires.
December 2, 2015
Guide to luminescence dating techniques and their application for paleoseismic research [PDF]
By Harrison Gray (GECSC), Shannon Mahan (GECSC), Tammy Rittenour, and Michelle Nelson. Utah Geological Survey Miscellaneous Publication 15-5.
Luminescence dating has been successfully applied to paleoseismic studies for the past 25 years and is progressing toward increasingly robust age determinations. Careful sampling and correct selection of sample sites exert two of the strongest controls on obtaining an accurate luminescence age. This invited paper (appearing in the proceedings volume for Basin and Range Province Seismic Hazards Summit III) covers the fundamentals of proper luminescence sample collection, laboratory preparation procedures, and resulting data analysis.
December 1, 2015
Geologic map of the Lake Roesiger 7.5-minute quadrangle, Snohomish County, Washington
By Joe Dragovich, Shannon Mahan (GECSC), Megan Anderson, James MacDonald, Jr., Joseph Schilter, Christina Frattali, Curtis Koger, Daniel Smith, Bruce Stoker, Andrew DuFrane, Michael Eddy, Recep Cakir, and Kirsten Sauer. Washington Division of Geology and Earth Resources Map Series 2015-01.
This 1:24,000 scale map published by the Washington State Department of Natural Resources describes the geology of the lower Snoqualmie and Skykomish River basins, a densely populated, seismically active region. The dating of Quaternary deposits within the map area was accomplished through infrared stimulated luminescence, with the samples processed and analyzed by the USGS Luminescence Dating Laboratory. The infrared stimulated luminescence age data is provided in the accompanying pamphlet.
November 30, 2015
A Green's function approach for assessing the thermal disturbance caused by drilling deep boreholes in rock or ice
By Gary Clow. Published in Geophysical Journal International.
The process of drilling deep boreholes to provide access for temperature and other measurements invariably disturbs the temperature field around a newly created borehole. This paper provides an analytic method for correcting borehole temperature measurements for the drilling disturbance using 2-D (radial and depth) Green's functions in cylindrical coordinates. Solutions are developed for three different boundary conditions at the borehole wall. Phase-change effects that occur while drilling through ice-rich permafrost are included through a migrating heat-source term. Inclusion of depth effects in the 2-D solution improves our ability to extract climate-change signals from borehole temperature measurements.
November 25, 2015
Determinants of public support for endangered and threatened species management: A case study of Cape Lookout National Seashore
By Lana Le, Ken Bagstad (GECSC), Philip Cook, Kirsten Leong, and Eva DiDonato. Published in the Journal of Park and Recreation Administration.
At national parks, where managers balance two aspects of their conservation mission—to protect resources and to provide for public enjoyment, gaining public support for management actions is especially important. This study conducted visitor surveys at Cape Lookout National Seashore (a unit of the National Park Service) and examined the variables that could potentially be associated with support for management actions related to threatened and endangered species management. The results show that among the variables examined, perceived values of threatened and endangered species, trust in park managers and the decision making process, and perceived share values with park managers were among the strongest indicators of support for management actions.
November 24, 2015
Temporal and spatial patterns of wetland extent influence variability of surface water connectivity in the Prairie Pothole Region, United States
By Melanie Vanderhoof (GECSC), Laurie Alexander, and Jason Todd. Published in Landscape Ecology.
In order to help improve our understanding of the multiple effects of wetlands on downstream waterways, this study quantified how surface water interactions between wetlands and streams varied both spatially and interannually at the landscape scale. The results show wetland extent correlates positively with the merging of wetlands and wetlands with streams. The degree of wetland merging was found to depend less on total wetland area or density and more on climate conditions as well as the threshold for how wetland/upland was defined. In contrast, the merging of wetlands with streams was positively correlated with stream density and inversely related to wetland density.
November 20, 2015
Potential Application of Radiogenic Isotopes and Geophysical Methods to Understand the Hydrothermal System of the Upper Geyser Basin, Yellowstone National Park
By Jim Paces (GECSC), Andrew Long, and Karl Koth. Published by the National Park Service.
Yellowstone National Park contains the world's largest concentration of geysers and geothermal features. To better understand the underlying hydrogeologic processes, this report presents the first 87Sr/86Sr and 234U/238U data for thermal water from the Upper Geyser Basin intended to evaluate whether heavy radiogenic isotopes might provide insight to sources of groundwater supply and how they interact over time and space. In addition, this report summarizes previous geophysical studies made at Yellowstone National Park and provides suggestions for applying non-invasive ground and airborne studies to better understand groundwater flow in the subsurface of the Upper Geyser Basin.
November 19, 2015
The GECSC website has added information about the USGS Luminescence Dating Laboratory. The principal purpose of the Laboratory is to provide depositional ages of sediment or event ages for archeological artifacts as determined by optically stimulated luminescence or thermoluminescence techniques. The lab website includes an overview of the principles behind luminescence dating, the kind of problems the technique could be applied to, instructions for sample collection in the field, a publication listing, and useful links to related dating resources. The OSL dating laboratory is a popular asset for Quaternary geologists, archeologists, and paleontologists".
November 16, 2015
Jeff Sloan, head of the USGS National Unmanned Aircraft Systems (UAS) Project Office, was interviewed by Dr. Keith Pannell on the University of Texas—El Paso public radio show "SCIENCE STUDIO". Their conversation touches on such topics as the logistics of carrying out a UAS mission, past and future work by the Project Office, and the future of UAS technology. Jeff also discussed his personal dream of applying UAS to the golf course as well as how this technology has been applied in his family's farming community in Iowa.
November 3, 2015
Evidence of a higher late-Holocene treeline along the Continental Divide in central Colorado
By Paul Carrara (GECSC) and Jack McGeehin. Published in The Holocene.
The altitude of former treelines in the mid-latitudes of the Northern Hemisphere provide information about the length of past growing seasons and growing season temperatures. Using remnants of bristlecone pine found above present treeline, this study obtained radiocarbon ages and annual ring counts that define a period of treeline as much as 30m above the present-day limit sometime before 2700 to about 800 cal. yr BP. The results indicate the timing and effects of a more favorable climate that allowed the establishment of a higher-than-present treeline and may serve as a proxy of the effects of a future warmer climate.
October 29, 2015
Projected future vegetation changes for the northwest United States and southwest Canada at a fine spatial resolution using a dynamic global vegetation model
By Sarah Shafer (GECSC), Patrick Bartlein, Elizabeth Gray, Richard Pelltier (GECSC). Published in PLoS ONE.
Future climate change may significantly affect the distribution of vegetation. This study used a dynamic global vegetation model to investigate potential future vegetation changes for 2070-2099 across the northwest United States and southwest Canada. The results indicate that some vegetation types may be able to persist under projected future climate conditions, such as forests in coastal regions of Oregon and Washington, while the distributions of other vegetation types in the study area are simulated to expand (e.g., cool open forest/woodland) or contract (e.g., shrub-steppe).
October 26, 2015
Geologic map of the Alamosa 30' x 60' quadrangle, south-central Colorado
By Ren Thompson (GECSC), Ralph Shroba (GECSC), Mike Machette, Chris Fridrich (GECSC), and Ted Brandt (GECSC). U.S. Geological Survey Scientific Investigations Map 3342.
This geologic map covers an area of the central San Luis Basin of Colorado that is bisected by the Rio Grande, and contains deposits that record surficial, tectonic, sedimentary, volcanic, magmatic, and metamorphic processes over the past 1.7 billion years. The publication, which supersedes USGS Open-File reports 2005-1392 and 2008-1124, includes the geologic map and report, as well a geospatial database available for download.
October 13, 2015
Research Geologist Shannon Mahan is featured in two Scholastic Books, both by Jordan Brown—"Dig it Up! Lots of Rocks! (Rocks and Gems)", aimed at young scientists from 8-10 years old, and "Deluxe Rocks and Gems Collections (Rocks, Minerals, and Gems)", aimed at the 10-12 year naturalist. The books with their accompanying kits have just been published and are available for purchase by school children across the country. Shannon, the featured "Meet a Geologist", cooperated with the project with the goal to inspire young inquiring minds to "reach for the rocks (and dirt!)".
October 9, 2015
Geologic Map of the Masters 7.5' Quadrangle, Weld and Morgan Counties, Colorado
By Margaret Berry (GECSC), Janet Slate, Jim Paces (GECSC), Paul Hanson, and Ted Brandt (GECSC). U.S. Geological Survey Scientific Investigations Map 3344.
The Masters 7.5' quadrangle is located along the South Platte River corridor on the semiarid plains of eastern Colorado. The mapped area contains surficial deposits that record alluvial, eolian, and hillslope processes that have operated in concert with environmental changes from Pleistocene to present time. Along with the map and georeferenced map PDFs, this publication includes downloadable GIS files, and an appendix detailing the U-series analyses and resultant 230Th/U ages that support the geologic map.
October 8, 2015
Effects of rapid urbanization on streamflow, erosion, and sedimentation in a desert stream in the American Southwest
By John Whitney (GECSC), Patrick Glancy, Susan Buckingham, and Arthur Ehrenberg. Published in Anthropocene.
This study describes the effects of rapid urban growth and development on a dry desert wash in the arid-semiarid region of Las Vegas Valley in southern Nevada. Increased wastewater flow from constantly increasing population growth during the late 20th century has resulted in accelerated erosion in Lower Las Vegas Wash; a dry wash otherwise characterized by infrequent flood erosion and deposition. Initial wastewater discharge created floodplain wetlands; however, increasing baseflow and storm runoff resulted in erosion that continued unabated until engineering interventions began in the 21st century. A 6.6 million cubic meter sediment slug was eroded from the wash and deposited in Las Vegas Bay in Lake Mead over ~25 years. This is the largest measured volume of erosion related to urbanization in the U.S.; it resulted in infrastructure losses, had a strong environmental impact on Lake Mead, and required a costly program of channel stabilization, flood protection and wetlands restoration. Drought conditions since 1999 are responsible for historic low lake levels and the infilling of Las Vegas Bay by redistribution of the wash delta sediments.
October 1, 2015
Early-Holocene warming in Beringia and its mediation by sea-level and vegetation changes
By P.J. Bartlein, M.E. Edwards, S.W. Hostetler, Sarah Shafer (GECSC), P.M. Anderson, L.B. Brubaker, and A.V. Lozhkin. Published in Climate of the Past.
Recent climate changes are affecting arctic ecosystems and generating land cover changes, such as expansion of woody vegetation into tundra, that may produce feedbacks to the climate system. To better understand the mechanisms controlling these feedbacks, this study used a regional climate model to simulate the effects of arctic land cover changes in Beringia (northeastern Siberia, Alaska, and northwestern Canada) ~11,000 years ago, focusing on the climate feedbacks produced by sea-level rise (e.g., flooding of the Bering-Chukchi land bridge), changes from tundra to deciduous broadleaf woody vegetation, and the formation of thaw lakes. Sea-level rise produced the largest climate effect (cooler summers, warmer winters), while vegetation changes produced warming in spring and early summer, and thaw lakes produced localized cooling in summer and warming in winter.
September 30, 2015
Effects of Fragmentation on the Spatial Ecology of the California Kingsnake (Lampropeltis californiae)
By Michael Anguiano and Jay Diffendorfer (GECSC). Published in the Journal of Herpetology.
The spatial ecology of 34 California Kingsnakes was studied by radiotracking the animals for up to 3 years across unfragmented and fragmented habitat with varying patch sizes and degrees of exposure to urban edges. It was found that there was no relationship between movement of the snakes and the degree of exposure to urban edges and fragmentation. The persistence of California Kingsnakes in fragmented landscapes may be related directly to their small spatial movement patterns, home-range overlap, and ability to use urban edge habitat.
September 29, 2015
Uranium-series ages of fossil corals from Mallorca, Spain: The "Neotyrrhenian" high stand of the Mediterranean Sea revisited
By Dan Muhs (GECSC), Kathleen Simmons (GECSC), Joaquín Meco, and Naomi Porat. Published in Palaeogeography, Palaeoclimatology, Palaeoecology.
On the island of Mallorca two separate high stands of sea—the "Eutyrrhenian" (thought to be approximately 120,000 yeas old) and the "Neotyrrhenian"—lie close to present sea level, implying paleo-sea levels that conflict, at least in part, with sea level records from far-field localities. This study obtained ages from the Neotyrrhenian bed corals, which when compared with previously published studies that employed other dating dating techniques show that the Neotyrrhenian and Eutyrrhenian deposits are not significantly different in age. The conclusion is that the Neotyrrhenian deposits are a beachrock facies of the same age as the Eutyrrhenian deposits.
September 18, 2015
GECSC Ecologist Jenny Briggs' work on forest disturbances in Colorado was featured in the 9News story "Researchers looking at Front Range forest health and fire". The report goes into the field with Jenny and Community College of Denver student Marianne Blackburn and professor Fleur Ferro as they monitor site areas that have been under observation since 2009. Ms. Blackburn and Professor Ferro are working on this GECSC project through the Research Experience for Community College Students (RECCS) mentoring program funded by the National Science Foundation and led by the CIRES Education group at the University of Colorado-Boulder.
September 9, 2015
Radiocarbon dating of terrestrial carbonates
By Jeff Pigati, appearing in the Encyclopedia of Scientific Dating Methods.
The Encyclopedia of Scientific Dating Methods aims to provide comprehensive coverage of dating methods in the geological sciences, biology, and archaeology. In a volume that includes almost 200 articles from international authors, GECSC Geologist Jeff Pigati provides an overview of the techniques and applications of radiocarbon dating terrestrial carbonates, including terrestrial gastropod shells, ostracodes, and foraminifera that are preserved in late Quaternary deposits.
September 4, 2015
Status and trends of land change in the Great Plains of the United States—1973 to 2000
Edited by Janis Taylor, William Acevedo, Roger Auch, and Mark Drummond (GECSC). U.S. Geological Survey Professional Paper 1794-B.
This report provides an assessment of the rates and causes of land-use and land-cover change in the Great Plains of the United States between 1973 and 2000. The chapters present brief summaries of the patterns and characteristics of land change observed in each of 17 ecoregions. In addition, a synthesis chapter summarizes the scope of land change observed across the larger Great Plains. Lead authors for chapters include GECSC Physical Scientists Mike Stier and Carl Rich as well as Geographer Mark Drummond who co-edited the volume.
August 12, 2015
Comparing ecoregional classifications for natural areas management in the Klamath Region, U.S.A.
By Daniel Sarr, Andrew Duff, Eric Dinger, Sarah Shafer (GECSC), Michael Wing, Nathaniel Seavy, and John Alexander. Published in Natural Areas Journal.
This study evaluates the ability of three ecoregional classifications (Bailey, Omernik, World Wildlife Fund) and two derived classification (Omernik Revised and Climate Zones) to explain species' distributions in the Klamath region of southwest Oregon and northwest California. Species distribution presence/absence data were analyzed for trees, amphibians, large and small mammals, and resident and migrant birds. Of these taxa groups, tree species distributions displayed the strongest correspondence with the ecoregional classifications and, of the five ecoregional classifications evaluated, the Omernik Revised classification had the best overall performance. The potential implications of these results for natural areas management are discussed. This work was done in collaboration with the National Park Service's Klamath Network.
August 5, 2015
Preliminary Geophysical Interpretations of Regional Subsurface Geology near the Questa Mine Tailing Facility and Guadalupe Mountain, Taos County, New Mexico
By Tien Grauch, Ben Drenth, Ren Thompson (GECSC), and Paul Bauer. USGS Open-File Report 2015-1129.
For remediation and reclamation purposes, the New Mexico Environment Department requested assistance from the USGS in assessing the subsurface geology of the area near the Tailing Facility of the Questa Mine. This report presents interpretations of the gravity and magnetic maps that the Survey developed from aeromagnetic data, regional gravity data, data from four ground magnetic traverses, geologic mapping, a digital elevation model, and information from a few shallow wells. These interpretations are preliminary and could be improved with additional detailed ground-based geophysics, comprehensive physical-property studies, and deep drillholes.
August 3, 2015
U.S. Geological Survey science for the Wyoming Landscape Conservation Initiative—2014 annual report
By Zachary Bowen and others, including Steve Garman of the GECSC. USGS Open-File Report 2015-1091.
This is the seventh report produced by the USGS for the Wyoming Landscape Conservation Initiative (WLCI), a science-based program founded to assess, monitor, and enhance aquatic and terrestrial habitats at a landscape scale in the southwest portion of the state. The report details the 26 Fiscal Year 2014 activities conducted by the USGS that address the specific management needs identified by WLCI partners. GECSC Ecologist Steve Garman contributions to the Initiative include modeling land use/cover change.
July 21, 2015
Assessing landscape change and processes of recurrence, replacement, and recovery in the Southeastern Coastal Plains, USA
By Mark Drummond (GECSC), Mike Stier (GECSC), Roger Auch, Janis Taylor, Glenn Griffith, Jodi Riegle (GECSC), Dave Hester (GECSC), Christopher Soulard, and Jamie McBeth (GECSC). Published in Environmental Management.
To better understand the various processes that cause land transformation, a data aggregation, validation, and attribution approach was developed and applied to an analysis of the Southeastern Coastal Plains. The approach integrates information from available national land-use, natural disturbance, and land-cover data to efficiently assess spatially-specific processes. Replacement processes, whereby a land use or cover is supplanted by a new land use, including urbanization and agricultural expansion, accounted for approximately 15% of the extent of change. Recurrent processes that contribute to cyclical changes in land cover, including forest harvest/replanting and fire, accounted for 83%. Most forest cover changes were recurrent, while the extents of recurrent silviculture and forest replacement processes such as urbanization far exceeded forest recovery processes. The total extent of landscape recovery, from prior land use to natural or semi-natural vegetation cover, accounted for less than 3% of change. Explicit identification of the process types and dynamics presented here may improve the understanding of land-cover change and landscape trajectory.
July 6, 2015
Onshore Industrial Wind Turbine Locations for the United States through July 2013
By Jay Diffendorfer (GECSC), Roger Compton, Louisa Kramer (GECSC), Zach Ancona (GECSC), and Donna Norton. USGS Data Series 817.
Unlike oil and gas wells, there has been a lack of publicly available information about wind turbines within the United States. This motivated a study by the USGS to map industrial-scale onshore wind turbine locations and record corresponding facility information and turbine technical specifications. The resulting database presented in this report has more than 47,000 wind turbine records that have been collected, digitized, locationally verified, and internally quality controlled.
July 1, 2015
Geologic map of the Orchard 7.5' quadrangle, Morgan County, Colorado
By Margaret Berry (GECSC), Janet Slate, Paul Hanson, and Ted Brandt (GECSC). USGS Scientific Investigations Map 3331.
The Orchard 7.5' quadrangle is located along the South Platte River corridor on the semi-arid plains of eastern Colorado, west of Ft. Morgan. The mapped area contains surficial deposits that record alluvial, eolian, and hillslope processes that have operated through environmental changes from the Pleistocene to the present. Along with the map and georeferenced map PDFs, this publication includes downloadable GIS files.
June 10, 2015
Late Quaternary sea-level history and the antiquity of mammoths (Mammuthus exilis and Mammuthus columbi), Channel Islands National Park, California, USA
By Dan Muhs (GECSC), Kathleen Simmons (GECSC), Lindsey Groves, Jack McGeehin, Randy Schumann (GECSC), and Larry Agenbroad. Published in Quaternary Research.
Mammoth fossils are sometimes found in Channel Islands National Park, and most date to the last glacial period (Marine Isotope Stage [MIS] 2, about 25,000 to 12,000 years ago). Recently, however, a tusk was found in the lowest marine terrace of Santa Rosa Island (MIS 5.1, about 80,000 years ago), which dates it to a time of relatively high sea level. Mammoths mostly likely swam to the islands, and the favorable times to do so (other than MIS 2) would have been during glacial periods MIS 6 (~150,000 years ago) or MIS 8 (~250,000 years ago) which were times of low sea level. The date of the MIS 5.1 fossil challenges the hypothesis that climate change, vegetation change, and decreased land area from sea-level rise were the causes of mammoth extinction at the Pleistocene/Holocene boundary on the Channel Islands, because pre-MIS 2 mammoth populations would have experienced similar or even more dramatic changes at the MIS 6/5.5 transition.
June 4, 2015
Radar attenuation and temperature within the Greenland Ice Sheet
By Joseph MacGregor, Jilu Li, John Paden, Ginny Catania, Gary Clow (GECSC), Mark Fahnestock, Prasad Gogineni, Robert Grimm, Mathieu Morlighem, Soumyaroop Nandi, Hélène Seroussi, and David Stillman. Published in the Journal Geophysical Research Earth Surface.
Currently, temperature information of ice within polar ice sheets comes from direct measurements made in the few boreholes produced by deep ice-coring projects. This article presents a different method of determining depth-average temperatures using the attenuation of airborne radar-sounding data and testing results against the network of borehole temperature measurements. Applying this method to the Greenland Ice Sheet, it was found that present temperature structure depends more strongly on past temperature and accumulation changes than previously recognized, particularly in southern Greenland. This new information is expected to provide important constraints for thermomechanical models used to investigate the future stability of the Greenland Ice Sheet.
June 2, 2015
Sea level, paleogeography, and archeology on California's Northern Channel Islands
By Leslie Reeder-Myers, Jon Erlandson, Dan Muhs (GECSC), and Torben Rick. Published in Quaternary Research.
Although global forces are at play, the effects of sea-level rise on ancient shorelines are highly localized due to variability in glacial isostatic adjustment (GIA) effects. Building on previous models of the Northern Channel Islands, this report presents late Pleistocene and Holocene paleogeographic reconstructions adjusted for regional GIA variability, which allow for more accurate estimates of shoreline locations and interpretations. These new interpretations have important implications for ecological reconstructions and archaeology of the study area, which are also summarized in the report.
May 29, 2015
Experimental Flights Using a Small Unmanned Aircraft System for Mapping Emergent Sandbars
By Paul Kinzel, Mark Bauer (GECSC), Mark Feller (GECSC), Christopher Holmquist-Johnson, and Todd Preston. Published in Great Plains Research.
This article presents the results of experimental flights using the T-Hawk unmanned aircraft system (UAS) conducted along reaches of the Platte River near Overton, Nebraska, in July 2013. The T-Hawk was equipped with a consumer-grade digital SLR camera to collect imagery of emergent sandbars. The still images along with surveyed control points were processed using photogrammetric software to generate orthophotographs and digital elevation models of the reaches. It was found that if adequate survey control is established, a UAS combined with photogrammetry software shows promise for accurate monitoring of emergent sandbar morphology and river management activities in short (1-2 km) river reaches.
May 29, 2015
Geologic map of the southern White Ledge Peak and Matilija quadrangles, Santa Barbara and Ventura Counties, California
By Scott Minor and Ted Brandt. USGS Scientific Investigations Map 3321.
This report presents a 1:24,000 scale digital geologic strip map of the southern parts of the contiguous White Ledge Peak and Matilija 7.5' quadrangles in coastal southern California, that along with USGS Scientific Investigations Map 3001 completes a 69-km-long east-west mapping transect from Goleta to Ojai. The map and accompanying pamphlet provide new insights and constraints on Neogene-through-Quaternary tectonic deformation and consequent landscape change, including geohazards in the urbanized southern flank of the Santa Ynez Mountains. Also included in the publication are a uniform geologic digital geodatabase and map plot files that can be used for visualization, analysis, and interpretation of the area's geology, geologic hazards, and natural resources.
May 27, 2015
Forecasting and evaluating patterns of energy development in southwestern Wyoming
By Steve Garman. Wyoming Landscape Conservation Initiative (WLCI) Fact Sheet 7.
Understanding the effects that future oil and natural gas development will have on wildlife populations in southwestern Wyoming, an area containing a significant portion of the Nation's remaining intact sagebrush steppe ecosystem, led to the development of an Energy Footprint simulation model. The goal of this modeling effort is to use measures of energy production, surface disturbance, and potential effects on wildlife to identify build-out designs that minimize the physical and ecological footprint of development for different levels of energy production and development costs. This Fact Sheet summarizes model results that evaluated the implications of using fewer well pads while maintaining the same level of energy production in the Atlantic Rim Project Area.
May 22, 2015
A multi-proxy record of hydroclimate, vegetation, fire, and post-settlement impacts for a subalpine plateau, central Rocky Mountains, U.S.A.
By Lesleigh Anderson (GECSC), Andrea Brunelle, and Bob Thompson (GECSC). Published in The Holocene.
This study compares post-settlement disturbance in the central Rocky Mountains in northwest Colorado to long-term patterns of the last few millennia. The research indicates that vegetation and fire regimes changed significantly in response to hydrologic change of the last two thousand years, and post-settlement disturbance was superimposed upon the resulting landscape.
May 15, 2015
Preliminary methodology to assess the national and regional impact of U.S. wind energy development on birds and bats
By Jay Diffendorfer (GECSC), Julie Beston (GECSC), Matt Merrill, Jessica Stanton, Margo Corum, Scott Loss, Wayne Thogmartin, Doug Johnson, Richard Erickson, and Kevin Heist. USGS Scientific Investigations Report 2015-5066.
This report presents a methodology, developed by the USGS, that assesses the impacts of wind energy development on wildlife. It is currently applicable to birds and bats, focuses primarily on the effects of collisions, and can be applied to any species that breeds in, migrates through, or otherwise uses any part of the United States. The methodology is intended to assess species at the national scale and is fundamentally different from existing methods focusing on impacts at individual facilities.
May 8, 2015
The WAIS Divide deep ice core WD2014 chronology—Part 1: Methane synchronization (68-31 kaBP) and the gas age-ice age difference
By Christo Buizert, Kurt Cuffey, Jeff Severinghaus, Daniel Baggenstos, T.J. Fudge, Eric Steig, Bradley Markle, Mai Winstrup, Rachael Rhodes, Ed Brook, Todd Sowers, Gary Clow (GECSC), Hai Cheng, Lawrence Edwards, Michael Sigl, Joe McConnell, and Ken Taylor. Published in Climate of the Past.
The West Antarctic Ice Sheet Divide ice core is a newly drilled, high-accumulation deep ice core that provides Antarctic climate records of the past ~68,000 years at unprecedented temporal resolution. This report presents a chronology for the deep part of the core (67,800-31,200 years BP), which is based on stratigraphic matching to annual-layer-counted Greenland ice cores using globally well-mixed atmospheric methane. The analysis of this ice core reveals the timing of atmospheric greenhouse gas variations relative to Antarctic climate, as well as the interhemispheric phasing of the "bipolar seesaw".
May 4, 2015
Precise interpolar phasing of abrupt climate change during the last ice age
By the WAIS Divide Project Members. Published in Nature.
GECSC members Gary Clow, Joan Fitzpatrick, and Eric Cravens were part of the WAIS Divide Project team that acquired and analyzed a new, highly detailed ice core from West Antarctica. The goal of this research was to determine the relative timing of temperature changes in the Arctic and Antarctic with a precision of several decades. The dating of the new core revealed a consistent link between abrupt temperature changes in the Arctic and Antarctic during the last ice age, with changes starting in the Arctic and taking about 200 years for ocean currents to redistribute the heat to Antarctica.
May 1, 2015
Geologist Randy Schumann is quoted in the Los Angeles Times article "Researcher says a sinking Santa Catalina could pose tsunami threat". For more than a century, scientists have debated whether Santa Catalina Island, off the Southern California coast, is uplifting or subsiding. The article reports on a recent study by a Stanford University researcher that suggests the island may be subsiding, contradicting the findings presented in a 2012 Geomorphology paper Tectonic influences on the preservation of marine terraces: Old and new evidence from Santa Catalina Island, California, authored by Schumann, Scott Minor, Dan Muhs (all of GECSC), Jack McGeehin (USGS, Reston), and Lindsey Groves (Los Angeles Museum of Natural History).
April 21, 2015
Isotopes in North American Rocky Mountain Snowpack 1993-2014
By Lesleigh Anderson (GECSC), Max Berkelhammer, and Alisa Mast. Published in Quaternary Science Reviews.
This report documents isotopic ratios in Rocky Mountain snowpack. Changes in snowpack and water resources have significant impacts on alpine ecosystems, and it is important to understand their response to climate forcing such as temperature and dominant storm trajectories. A process-based understanding of climate-snowpack relationships from networks such as the Isotopes in Rocky Mountain Snowpack network facilitates interpretation of long-term patterns of snowpack and temperature from paleoclimate proxy records.
April 7, 2015
U.S. Geological Survey Unmanned Aircraft Systems (UAS) Roadmap 2014
By Jill Cress, Mike Hutt, Jeff Sloan, Mark Bauer, Mark Feller, and Susan Goplen. USGS Open-File Report 2015-1032.
The National Unmanned Aircraft Systems (UAS) Project Office, located in Denver as part of the Geosciences and Environmental Change Science Center, has been a key player in performing research on and operational studies of this emerging data-collection technology. UAS have been found to be more cost-effective, safer, and better platforms for studying climate and landscape changes, conducting wildlife inventories, and supporting land management missions than traditional methods. This report provides an overview of the technology, procedures, and lessons learned from missions conducted by U.S. Department of the Interior agencies and describes strategic actions that the Department could take in order to fully utilize this technology going forward.
April 2, 2015
Linking social values and ecosystem services: Social-ecological hotspots for public lands management
By Ken Bagstad (GECSC), James Reed, Darius Semmens (GECSC), Ben Sherrouse (GECSC), and Austin Troy. Published in Regional Environmental Change.
In this paper, hot and cold spots for perceived and modeled ecosystem services were mapped by synthesizing results from a social-values mapping study of residents living near the Pike-San Isabel National Forest, located in the Southern Rocky Mountains, with corresponding biophysically modeled ecosystem services. The goal was to determine whether publicly valued locations for aesthetic, biodiversity, and life-sustaining values relate meaningfully to results from corresponding biophysical ecosystem service models. The study found weak relationships between perceived and biophysically modeled services, indicating that public perception of ecosystem service provisioning regions is limited. Biophysical and cultural ecosystem services hotspot maps for ecosystem services may provide more useful information for forest planning when combined than alone.
April 1, 2015
Long-term controls on soil organic carbon with depth and time: A case study from the Cowlitz River Chronosequence, WA USA
By Corey Lawrence (GECSC), Jennifer Harden, Xiaomei Xu, Marjorie Schulz, and Susan Trumbore. Published in Geoderma.
In this study, an extensive dataset of soil profile chemistry and mineralogy is compiled from a soil chronosequence formed along the Cowlitz River, Washington, with soils ranging in age from 250 to 1200,000 years and spanning a developmental gradient encompassing clear changes in soil mineralogy, chemistry, and surface area. Comparison of these and other metrics of soil development with soil organic carbon properties reveal several relationships that may be diagnostic of the long-term coupling of soil development and carbon cycling. The results of the study advance a framework for linking temporal (e.g., millennial scale) changes in soil development with the storage and stability of soil organic carbon, including depth-dependent evolution of soil mineral profiles and stabilization of soil organic carbon through organic-mineral and organic-metal associations.
March 30, 2015
Sample descriptions and geophysical logs for cored well BP-3-USGS, Great Sand Dunes National Park and Preserve, Alamosa County, Colorado
By V.J.S. Grauch, Gary Skipp (GECSC), Jonathan Thomas, Joshua Davis, and Mary Ellen Benson. USGS Data Series 918.
Well BP-3-USGS, drilled in 2009 but now plugged and abandoned, was sited to test hypotheses developed from geophysical studies and to answer questions about the history and evolution of Pliocene and Pleistocene Lake Alamosa. This report presents lithologic descriptions from the well samples and core, along with a compilation and basic data processing of the geophysical logs. It provides a basis from which future studies can answer questions regarding geologic history and climate change, groundwater hydrology, and geophysical interpretation in the San Luis Valley.
March 26, 2015
Field-Based Description of Rhyolite Lava Flows of the Calico Hills Formation, Nevada National Security Site, Nevada
By Don Sweetkind (GECSC) and Shiera Bova. USGS Scientific Investigations Report 2015-5022.
This report, produced in cooperation with the U.S. Department of Energy, describes the lithologic variability of the Calico Hills Formation based on geologic mapping of surface outcrops near the Calico Hills and Yucca Mountain in the western part of the Nevada National Security Site in southern Nevada. Map data and outcrop descriptions are used to develop information on the individual rhyolite lava flows within the Calico Hills Formation, including their lateral extent and continuity, thickness, and field-based criteria useful in stratigraphic correlation. Geologic mapping and outcrop description of the lava-bearing Calico Hills Formation are intended to provide a useful surface analog to similar rocks buried beneath Pahute Mesa in the northwestern part of the Nevada National Security Site. The geologic mapping results may be useful in developing, or at least corroborating, conceptual models of Calico Hills Formation lithofacies variations at Pahute Mesa.
March 24, 2015
Land-cover change in the Gulf Coastal Plains and Ozarks Landscape Conservation Cooperative, 1973 to 2000
By Mark Drummond, Mike Stier, and Alisa Coffin. USGS Open-File Report 2015-1018.
This report summarizes baseline land-cover change information from between 1973 and 2000 for the Gulf Coastal Plains and Ozarks Landscape Conservation Cooperative (LCC). Using sample data from the USGS Land Cover Trends dataset, the study developed estimates of change for 10 land-cover classes in the LCC, with results showing that an estimated 17.7 percent of the LCC land cover had a change during the 27-year period. The report also highlights causes and challenges of land-cover change.
March 23, 2015
Insufficient Sampling to Identify Species Affected by Turbine Collisions
By Julie Beston (GECSC), Jay Diffendorfer (GECSC), and Scott Loss. Published in The Journal of Wildlife Management.
The collection of information on bird fatalities caused by collisions with turbines has been undertaken at many wind energy facilities. This study compared the results of collection efforts at 50 North American wind facilities and found that facilities with short intervals between sampling events and high sampling effort detected more affected species, but many wind facilities appeared to be undersampled. Most studies in North America are of a shorter duration, suggesting these studies may not be capable of detecting the full range of species actually killed, which may understate impacts for rare species of conservation concern that collide infrequently with turbines but suffer disproportionate consequences from those fatalities.
March 13, 2015
National unmanned aircraft systems project office
By Susan Goplen and Jeff Sloan. USGS Fact Sheet 2015-3013.
The USGS National Unmanned Aircraft Systems (UAS) Project Office leads the implementation of UAS technology in the larger Department of the Interior. This Fact Sheet gives an overview of the Project Office capabilities in both planning and undertaking UAS missions as well as providing multiple examples of geospatial data products derived from UAS data acquisitions.
March 9, 2015
Obtaining valid geologic models from 3-D resistivity inversion of magnetotelluric data at Pahute Mesa, Nevada
By Brian Rodriguez and Don Sweetkind (GECSC). USGS Open-File Report 2015-1019.
This report summarizes the results of a three-dimensional (3-D) resistivity inversion simulation conducted without a priori information on the known 3-D distribution of subsurface geology at Pahute Mesa. The simulation was compared to the "known" model, with the results showing that it was generally able to reproduce the gross resistivity structure of the "known" model but with simulated conductive volcanic composite unit horizons that were often too shallow in comparison. The 3-D inversion results show some promise of recovering the resistivity and thickness of the buried volcanic composite confining units, but numerous model uncertainties and artifacts exist.
March 4, 2015
Atlas of relations between climatic parameters and distributions of important trees and shrubs in North America—Revisions for all taxa from the United States and Canada and new taxa from the western United States
By Bob Thompson (GECSC), Kathy Anderson, Richard Pelltier (GECSC), Laura Strickland (GECSC), Sarah Shafer (GECSC), Patrick Bartlein, and Andrew McFadden. U.S. Geological Survey Professional Paper 1650-G.
This is the seventh volume in an atlas series that explores the relations between the geographic distributions of woody plant species and climatic variables in North America. These relationships are presented in graphical and tabular form for use in biogeographic, ecologic, paleoclimatic, and global-change research. This volume of the atlas provides numerous changes, updates, and enhancements from previous volumes including added coverage of Canada, the addition of monthly temperature and precipitation values, and the addition of 148 new species from the arid and semiarid western United States.
February 20, 2015
Social values for ecosystem services, version 3.0 (SolVES 3.0)—Documentation and user manual
By Ben Sherrouse and Darius Semmens. USGS Open-File Report 2015-1008.
SolVES is a geographic information system (GIS) tool developed by the GECSC. It can be used to incorporate quantified, spatially explicit social-values information into ecosystem service assessments. Among the updates included in the SolVES 3.0 release are new survey point weighting options and improved categorical data graphs. Accompanying this release is the revised documentation and user manual.
February 13, 2015
The new Cenozoic Landscape Evolution of the Southern Rocky Mountains Project website gives an overview of mapping and research conducted by the GECSC and collaborating USGS Science Centers. The project utilizes a combination of geologic mapping, geophysical surveys, basin modeling, and structural, tectonic, neotectonic, geomorphic, volcanic, stratigraphic, and geochronologic studies to better understand the evolution of the geologic landscape of the southern Rocky Mountains province, which includes parts of Colorado, New Mexico, and Wyoming. Besides providing information to help us better understand the geologic framework of the region, many of the objectives of this project also address societal issues related to groundwater management, geothermal and traditional energy resources, and geologic hazards.
February 4, 2015
Evidence for long-time scale (1000-year) changes in hydrothermal activity induced by seismic events
By Trevor Howald, Mark Person, Andrew Campbell, Virgil Luth, Albert Hofstra, Don Sweetkind (GECSC), Carl Gable, Amlan Banerjee, Elco Luijendijk, Laura Crossey, Karl Karlstrom, Shari Kelley, and Fred Phillips. Published in Geofluids.
The pollen 14C age and oxygen isotopic composition of siliceous sinter deposits from the former Beowawe geyser field reveal evidence of two hydrothermal discharge events that followed relatively low-magnitude earthquakes of Holocene and late Pleistocene age along the Malpais fault zone in Whirlwind Valley, Nevada. The model used suggests that the Malpais fault zone is composed of several pathways to the surface, each pathway having different fault zone apertures. As the most permeable conduit is sealed off by mineralization, alternative conduits are accessed along the Malpais fault.
January 28, 2015
Contributions by the GECSC National Land Cover Database (NLCD) Team have been included in recent updates to the 2011 NLCD, which now includes
Alaska. The GECSC NLCD Team (Cartographers Catherine Costello and Rick Poss and Physical
Scientist Lori Baer) is currently performing an accuracy assessment of the 2011 database for the
conterminous U.S, developing improved methods and procedures for producing its 2016 edition, as well
as working on procedures for producing a NLCD for the 1990's and 1980's. The overall purpose of the
NLCD is to provide complete, current, consistent, and public domain information on the Nation's land
January 26, 2015
Optimizing conservation strategies
for Mexican free-tailed bats: A population viability and ecosystem services approach
Ruscena Wiederholt, Laura López-Hoffman, Colleen Svancara, Wayne Thogmartin, Gary McCracken,
Jay Diffendorfer (GECSC), Ken Bagstad (GECSC), Paul Cryan, Amy Russell, Darius Semmens (GECSC), and
Rodrigo Medellín. Published in Biodiversity and Conservation
This article presents a
conservation prioritization method for maternity roosts of the Mexican free-tailed bat, a species
that winters in central and southern Mexico and migrates north to large maternity roosts in the
southwestern U.S. and northern Mexico. These bats provide valuable ecosystem services such as insect
pest-suppression in agricultural areas and recreational viewing opportunities. Using data on each
roost's contribution to the species' population viability, ecosystem services provided, and risks to
the roost structure and bat population within a multi-attribute utility function, we demonstrate the
most critical maternity roosts to protect, which can aid in conservation of the species.
January 21, 2015
Directly dated MIS 3 lake-level record from
Lake Manix, Mojave Desert, California, USA
By Marith Reheis (GECSC), David Miller, John
McGeehin, Joanna Redwine, Charles Oviatt, and Jordon Bright. Published in Quaternary Research.
This study found that during marine isotope stage 3 (MIS 3), at least eight highstands of Lake
Manix occurred from about 45,000 to 25,000 years ago. The ages of these highstands, representing
cool wet conditions in southern California, correlate to Dansgaard-Oeschger stadials recorded in
Greenland and the North Atlantic. These high lake levels in such a low-latitude desert setting as
the Manix basin require significant rearrangements of atmospheric circulation and suggest that the
southern lakes were sustained by greatly increased precipitation from tropical sources.
January 16, 2015
On the effects of
scale for ecosystem services mapping
By Adrienne Grêt-Regamey, Bettina Weibel, Ken
Bagstad (GECSC), Marika Ferrari, Davide Geneletti, Hermann Klug, Uta Schirpke, and Ulrike Tappeiner.
Published in PLoS ONE.
Using four case studies from mountainous regions in Europe and the
U.S., information gains and losses were quantified when using fine and coarse resolution spatial
data for five ecosystem services—carbon sequestration, flood regulation, agricultural
production, timber harvest, and scenic beauty. The analysis shows that ecosystem services assessment
results differ substantially between the fine and coarse resolution analyses in all case studies and
across all services, but the scale effect is not equally strong for all ecosystem services. The
report provides recommendations for ecosystem services mapping that can help make results more
comparable and account for geographic questions related to data resolution.
January 7, 2015
In the Mountain Town News article "When the global climate
wiggles, it shakes its hips at high elevations," writer Allen Best gives an overview of some of
the findings from the Snowmastodon fossil excavation of 2010. Geologist Jeff Pigati, GECSC project
leader for the Snowmastodon study,
provides an explanation of what proxies tell us about high altitude climates in relation to global
climate as they were when the animals were present at the site between ~140,000 and 77,000 years
ago. GECSC Geologist Laura Strickland was also interviewed for the article, and she discusses what
the study of the vegetation history revealed. Information from this article also appeared in the
Denver Post opinion piece "The lessons from
January 5, 2015
Steady-state numerical groundwater flow model of the
Great Basin carbonate and alluvial aquifer system
By Lynette Brooks, Melissa Masbruch,
Don Sweetkind (GECSC), and Susan Buto. USGS Scientific Investigations Report 2014-5213.
report describes the construction, calibration, evaluation, and results of a steady-state numerical
groundwater flow model of the Great Basin carbonate and alluvial aquifer system (an area
encompassing 110,000 square miles across five states) that was developed as part of the USGS
National Water Census Initiative to evaluate the nation's groundwater availability. The numerical
model uses MODFLOW-2005, and incorporates and tests complex hydrogeologic and hydrologic elements of
a conceptual understanding of an interconnected groundwater system throughout the region, including
mountains, basins, consolidated rocks, and basin fill.
December 30, 2014
Surficial Geology and Stratigraphy of Pleistocene Lake
Manix, San Bernardino County, California
By Marith Reheis (GECSC), Joanna Redwine, Elmira
Wan, Jack McGeehin, and Paco VanSistine (GECSC). USGS Scientific Investigations Map 3312.
This map focuses on the extensive exposures created by incision of the Mojave River and its
tributaries into the interbedded lacustrine and alluvial deposits within the subbasins of Lake
Manix, and extends from the head of Afton Canyon to Manix Wash. It illuminates the geomorphic
development and depositional history of the lake and alluvial fans within the active tectonic
setting of the eastern California shear zone, especially interactions with the left-lateral Manix
fault. Along with the two map sheets and report, this publication includes downloadable GIS files
and numerous photographs.
December 24, 2014
The new Sustainable Landscapes Project website
gives an overview of research conducted by the GECSC on the dynamics of landscape conservation and
the emerging capacity for sustainable socio-ecological interaction in the face of human population
pressure and resulting environmental changes. The issues studied by the project include
afforestation and forest persistence, maintenance of productive agricultural systems, ecological
restoration and recovery, and changes at the urban fringe. The web site gives an overview of
comparative urban landscapes studies underway in the southern coastal plains of Texas, Louisiana,
and Florida, as well as photo comparisons of landscape recovery.
December 23, 2014
The Association of American Geographers, in
collaboration with USGS and the Group on Earth Observations, has published A New Map of Global Ecological Land Units—An
Ecophysiographic Stratification Approach. It describes the concepts and methods for delineating
ecological land units which have been developed in response to the need for a high resolution,
standardized, and data-derived map of global ecosystems for use in analyses of climate change
impacts, assessments of economic and non-economic value of ecosystem goods and services,
biodiversity conservation planning, and natural resource management. GECSC Geographer Paco Van
Sistine developed the global landforms data layer used in this report.
December 22, 2014
The Snowmastodon Project
Quaternary Research special volume, edited by Jeff Pigati (GECSC) and Ian Miller.
discovery of the Ziegler Reservoir fossil site near Snowmass Village, Colorado in October 2010 led
to the recovery of bones belonging to an array of extinct Pleistocene animals, including mastodons,
mammoths, deer, sloths, bison, horses, camels, salamanders and rodents. The world-class
paleontological site also featured geologic evidence of climate conditions during the Last
Interglacial Period. A special volume of Quaternary Research includes 14 articles about the site by
scientists from the USGS, Denver Museum of Nature and Science, and academic institutions around the
world. USGS scientists contributing to this volume include Tom Ager, Bruce Bryant, Paul Carrara,
Harrison Gray, Jeff Honke, Shannon Mahan, Dan Muhs, Jim Paces, Jeff Pigati, Gary Skipp, Laura
Strickland, and Bob Thompson.
December 17, 2014
Radiocarbon dating loess deposits in the
Mississippi Valley using terrestrial gastropod shells (Polygyridae, Helicinidae, Discidae)
By Jeff Pigati (GECSC), Jack McGeehin, Dan Muhs (GECSC), David Grimley, and Jeff Nekola.
Published in Aeolian Research.
Gastropod shells (mostly Succineidae) have been used to
successfully date late Quaternary loess deposits in Alaska and the Great Plains. However,
Succineidae shells are rarely found in loess deposits in the Mississippi Valley. This study was
conducted to determine whether shells of gastropod taxa that are common to the Mississippi Valley
could also provide reliable carbon-14 ages. The results show that, for most of the taxa studied,
shell ages were accurate to within a few hundred years, which is acceptable for certain types of
scientific research. The study also found that shells of the genus Mesodon gave ages that
were up to several thousand years too old and should be avoided for dating whenever possible.
December 16, 2014
Quaternary geologic map of the north-central part of the
Salinas River Valley and Arroyo Seco, Monterey County, California
By Emily Taylor and Don
Sweetkind. USGS Scientific Investigations Map 3260.
The 1:24,000 and 1:50,000 scale maps
presented in this report summarize the geology of the Arroyo Seco, a perennial drainage in the
central Coast Range of California. The geology of the Arroyo Seco records a sequence of strath
terraces which preserve an erosional and depositional history, controlled by both climate change and
regional tectonics. Along with the two map sheets and pamphlet, this publication includes
downloadable GIS files.
December 15, 2014
DOI/GTN-P climate and active-layer data acquired in the
National Petroleum Reserve-Alaska and the Arctic National Wildlife Refuge, 1998-2013
Frank Urban and Gary Clow. USGS Data Series 892.
This online report provides an additional
two years of air temperature, wind speed, wind direction, ground temperature, soil moisture, snow
depth, rainfall, up- and downwelling shortwave radiation, and atmospheric pressure data to that
previously published in USGS Data Series 812. In addition to presenting data, this report also
describes monitoring, data collection, and quality control methodology. The data collection is
ongoing and done in close collaboration with the Bureau of Land Management and the U.S. Fish and
December 8, 2014
The Arizona Daily Star story Drones new research tool for wildlife, land covers an aerial survey
of the Las Ciengas National Conservation Area conducted jointly by the USGS Unmanned Aircraft
Systems (UAS) Project Office, the Bureau of Land Management, and Nature Conservancy. The goal of the
project was to provide photographs needed by researchers to help them monitor grassland restoration
efforts. The benefits of using UAS technology are explained as well as the how the USGS and other
government agencies work with the Federal Aviation Administration to get authorization for their
projects. (Icon photo by A.E. Araiza/Arizona Daily Star)
December 8, 2014
Physical properties of the WAIS Divide ice
By Joan Fitzpatrick (GECSC), Donald Voigt, John Fegyveresi, Nathan Stevens, Matthew
Spencer, Jihong Cole-Dai, Richard Alley, Gabriella Jardine, Eric Cravens (GECSC), Lawrence Wilen, TJ
Fudge, and Joseph McConnell. Published in the Journal of Glaciology.
The WAIS (West Antarctic
Ice Sheet) Divide deep ice core was recently completed to a total depth of 3405 m, ending ~50 m
above the bed. Investigation of the visual stratigraphy and grain characteristics indicates that the
ice column at the drilling location is undisturbed by any large-scale overturning or discontinuity,
and therefore the climate record developed from this core is likely to be continuous and
robust. The characteristics of the core, such as ice grain sizes, bubble-number densities, bubble
sizes and shapes, bubble elongations, and crystallographic orientations are described.
December 5, 2014
Resource Management and Ecosystem Services Guidebook, produced by the National Ecosystem
Services Partnership (NESP), provides an overview of how agencies can use ecosystem services in
resource management. Among the authors are GECSC Research Economist Ken Bagstad who co-authored the
guidebook chapter on monetary valuation of ecosystem services, and along with GECSC Physical
Scientist Ben Sherrouse, participated in the Technical Working Group that contributed to the
development of the assessment framework. GECSC Physical Scientist Darius Semmens was a member of
the NESP's Community of Practice that provided feedback on the guidebook's design and content.
December 2, 2014
Aeolian responses to climate variability
during the past century on Mesquite Lake Playa, Mojave Desert
By John Whitney (GECSC),
George Breit, Susan Buckingham, Rich Reynolds (GECSC), Rian Bogle, Lifeng Luo, Harland Goldstein
(GECSC), and John Vogel. Published in Geomorphology.
This paper is the first study to
recognize short-term cycles of aeolian activity related to a modern regional climate pattern
controlled by changes in sea-surface temperature. The study documents the last ~100 years of aeolian
history on the Mesquite Lake playa, and interprets the response of geomorphic processes to changing
climatic conditions. Sand-sheet development and migration, as well as yardang (wind-eroded landform)
formation, appear closely related to episodes of drought and wetness linked to variations of the
Pacific Decadal Oscillation. The findings are relevant to other playa settings beyond Nevada and
California for its demonstration of the influence of short-term climatic variability on aeolian
processes; its combination of many kinds of observations and measurements; its documentation of
local sand-cementation processes; and its use of yardangs to recognizing recurrent patterns of wind
erosion on a century timescale. Ongoing aeolian activity at Mesquite Lake playa has important
environmental implications, because the playa is a major source of dust and dust storms to the
downwind communities in Las Vegas Valley, Nevada (pop. 1.2 million).
November 26, 2014
U.S. Geological Survey science for the Wyoming
Landscape Conservation Initiative—2013 annual report
By Zachary Bowen and others,
including GECSC Ecologist Steve Garman. Published as USGS Open-File Report 2014-1213.
the sixth report produced by the USGS for the Wyoming Landscape Conservation Initiative (WLCI), a
science-based program founded to assess, monitor, and enhance aquatic and terrestrial habitats at a
landscape scale in the state. The report details the 25 Fiscal Year 2013 activities conducted by the
USGS that address the specific management needs identified by WLCI partners. GECSC Ecologist Steve
Garman contributions to the Initiative include modeling land use/cover change.
November 17, 2014
Composition of dust deposited to snow
cover in the Wasatch Range (Utah, USA): Controls on radiative properties of snow cover and
comparison to some dust-source sediments
By Rich Reynolds (GECSC), Harland Goldstein
(GECSC), Bruce Moskowitz, Ann Bryant, McKenzie Skiles, Raymond Kokaly, Cody Flagg, Kimberly Yauk,
Thelma Berquó, George Breit, Michael Ketterer, Daniel Fernandez, Mark Miller, and Thomas
Painter. Published in Aeolian Research.
This study provides the first comprehensive analyses
of the particle-compositional causes of accelerated snow melt in the American West. It was found
that goethite (an iron oxide mineral) and carbonaceous matter are the main influences on lowering
snow-cover albedo on the basis of spectroscopic, magnetic, chemical, and electron microscopic
methods. The results of this study will improve models that factor in effects of dust on snow-melt
rates by providing snow hydrologists with new quantitative inputs.
November 13, 2014
Coastal tectonics on the eastern margin
of the Pacific Rim: late Quaternary sea-level history and uplift rates, Channel Islands National
Park, California, USA
By Dan Muhs (GECSC), Kathleen Simmons (GECSC), Randy Schumann
(GECSC), Lindsey Groves, Stephen DeVogel, Scott Minor (GECSC), and DeAnna Laurel. Published in
Quaternary Science Reviews.
Coastal California is very active tectonically and geomorphic
expressions of this include uplifted marine terraces. In this study, the terraces on San Miguel
Island and Santa Rosa Island were mapped and new age estimates were generated using uranium-series
dating of fossil corals and amino acid geochronology of fossil mollusks. The study shows that uplift
rates on these two islands are relatively low and similar to most other parts of southern
California, challenging a recent study that suggested that uplift rates were extraordinarily high
for this area.
November 12, 2014
map of the west-central Buffalo National River region, northern Arkansas
By Mark Hudson
and Kenzie Turner. USGS Scientific Investigations Map 3314.
This 1:24,000-scale map
summarizes the geology of the west-central Buffalo National River region in the Ozark Plateaus
region of northern Arkansas. Along with the map sheets, this report provides a geologic map database
of the map area that improves understanding of the regional geologic framework, its influence on
regional groundwater flow systems, and the Quaternary history of landscape development.
November 3, 2014
Spatial and temporal patterns of dust
emissions (2004-2012) in semi-arid landscapes, southeastern Utah, USA
By Cody Flagg,
Jason Neff, Rich Reynolds (GECSC), and Jayne Belnap. Published in Aeolian Research.
paper reports dust fluxes (2004-2012) from a network of 85 passive dust collectors located across
numerous plant communities, soil types, and land-use histories in the cold, high Colorado Plateau
Desert. This first large-scale quantification of dust emissions from this region improves our
understanding of the effects of man-made disturbances and climate on the interacting dynamics of
wind erosion, perennial and annual plants, and conditions of biologic soil crust.
October 29, 2014
Surficial geologic map of the Red Rock Lakes area,
By Ken Pierce (GECSC), Tara Chesley-Preston, and Richard Sojda. U.S.
Geological Survey Open-File Report 2014-1157.
The Red Rock Lakes map is located in
southwestern Montana and centers on the Red Rock Lakes National Wildlife Refuge. The terrain of the
mapped area varies from the Centennial Valley and Centennial Range to watery lowlands containing
Upper and Lower Red Rock Lakes, many ponds, and peat lands. New mapping within this map provides
insight to the Quaternary evolution of the Centennial Valley and associated southern-bounding
Centennial fault. Along with the map and pamphlet, this publication includes downloadable GIS
October 28, 2014
Ecological Change on California's Channel Islands
from the Pleistocene to the Anthropocene
By Torben Rick, Scott Sillett, Cameron
Ghalambor, Courtney Hofman, Katherine Ralls, Scott Anderson, Christina Boser, Todd Braje, Daniel
Cayan, Terry Chesser, Paul Collins, Jon Erlandson, Kate Faulkner, Robert Fleischer, Chris Funk,
Russell Galipeau, Ann Huston, Julie King, Lyndal Laughrin, Jesus Maldonado, Kathryn McEachern, Dan
Muhs (GECSC), Seth Newsome, Leslie Reeder-Myers, Christopher Still and Scott Morrison. Published in
This report integrates data from multiple disciplines to illuminate the past,
present, and future of biodiversity on California's Channel Islands, an archipelago that has
undergone a wide range of land-use and ecological changes. The analysis presented spans
approximately 20,000 years, from before human occupation and through Native American
hunter-gatherers, commercial ranchers and fishers, the US military, and other land managers. It
demonstrates that long-term, interdisciplinary research provides insight into conservation
decisions, preserves rare and endemic taxa, and reduces the impacts of climate change on natural and
October 16, 2014
Glacial and Quaternary geology of the northern
Yellowstone area, Montana and Wyoming
By Ken Pierce (GECSC), Joseph Licciardi, Teresa Krause,
and Cathy Whitlock. Published in Geological
Society of America Field Guide 37—Exploring the Northern Rocky Mountains.
field trip of the Exploring the Northern Rocky Mountains Field Guide focuses on the glacial geology
and paleoecology beginning in Paradise Valley, Montana and progressing southward into northern
Yellowstone National Park. The stops on the route present glacial features with description and
information on their formation. Also presented here is an overview of the paleoecology and
paleo-fire history of the field trip area.
October 15, 2014
Identifying Sources of Aeolian
Mineral Dust: Present and Past
By Dan Muhs (GECSC), Joseph Prospero, Matthew Baddock, and
Thomas Gill. A chapter in Mineral Dust: A Key Player in the Earth System.
dust is an important component of the Earth's environmental systems and identifying its sources is
crucial to fully understanding the roles it plays. This chapter in Mineral Dust reviews the methods
used to identify dust sources active at present and in the past. The study of dust and its sources
also gives indications of what role it played during past glacial and interglacial periods and
indications of what can be expected in the future.
October 8, 2014
Characterizing recent and projecting
future potential patterns of mountain pine beetle outbreaks in the Southern Rocky Mountains
By Lu Liang, Todd Hawbaker (GECSC), Yanlei Chen, Zhiliang Zhu, and Peng Gong. Published in
The aim of this study was to quantify the landscape-level drivers that
explained the dynamic patterns of mountain pine beetle mortality, and simulate areas with future
potential mountain pine beetle mortality under projected climate-change scenarios in Grand County,
Colorado. The results show that neighborhood mortality, winter mean temperature anomaly, and
residential housing density were positively associated with mountain pine beetle mortality, whereas
summer precipitation was negatively related. The model used for this study implies that the impacts
of mountain pine beetle outbreaks on vegetation composition and structure, and ecosystem functioning
in Grand County are likely to increase in the future.
October 3, 2014
The misconception of ecosystem disservices:
How a catchy term may yield the wrong message for science and society
Villa, Ken Bagstad (GECSC), Brian Voigt, Gary Johnson, Ioannis Athanasiadis, and Stefano Balbi.
Published in Ecosystem Services.
This article points out problems that may arise when
economists describe natural phenomena that harm people or economic assets as an "ecosystem
disservice." Several examples are given where society attempts to mitigate these harms only to see
undesirable unintended consequences. It is argued that replacing the "disservices" concept with a
fuller understanding of ecosystem service flow dynamics is a more efficient way to advance both the
science of ecosystem services and the policy instruments that may lead to a more sustainable
October 3, 2014
Muhs (GECSC), Stephen Cattle, Onn Crouvi, Denis-Didier Rousseau, Jimin Sun, and Marcelo
Zárate. A chapter in Mineral Dust: A Key Player in the Earth System.
Loess covers a
significant portion of the land surface of the Earth and as such constitutes one of the most
important archives of long-term dust deposition. Paleosols represent periods of landscape stability
when loess deposition ceased or at least slowed significantly. Studies from several continents show
that loess in most regions was deposited during glacial periods and paleosols formed during
interglacial and interstadial periods.
September 19, 2014
The contributions of
Donald Lee Johnson to understanding the Quaternary geologic and biogeographic history of the
California Channel Islands
By Dan Muhs. Published in Monographs of the Western North
Donald Lee Johnson (1934–2013) spent over 50 years studying
diverse topics related to the California Channel Islands. During that time he made a number of
memorable contributions to our understanding of the geomorphology, Quaternary stratigraphy, soil
science, biogeography, archaeology, and history of the islands, including clarifying the origin of
Pleistocene pygmy mammoths that inhabited them. This article, part of the 8th California Islands
Symposium, gives an overview of some of those contributions.
September 17, 2014
The GECSC National Unmanned Aircraft Systems
Project Office and the U.S. Fish and Wildlife Service teamed up in August to conduct a second round
of Unmanned Aerial Systems surveys over Chase Lake National
Wildlife Refuge, North Dakota for a census of ground-nesting colonial waterbirds. This
proof-of-concept project focused on improved methodology for collecting census estimates of the
American white pelican, double-crested cormorants, gulls and other breeding species found at the
refuge. Detection of juvenile pelicans using improved sensors was the primary focus of this
September 9, 2014
Neotectonics and geomorphic evolution
of the northwestern arm of the Yellowstone Tectonic Parabola: Controls on intra-cratonic
extensional regimes, southwest Montana
By Cal Ruleman (GECSC), Mort Larsen, and Michael
Stickney. Published in Geological Society of
America Field Guide 37—Exploring the Northern Rocky Mountains.
fieldtrip, beginning and ending in Bozeman, Montana, looks at Quaternary surface ruptures that
characterize prehistoric earthquake magnitudes. It includes an overview of the active tectonics
within the Madison Valley and Hebgen Lake basin, site of the catastrophic Hebgen Lake earthquake of
August 18, 1959. This chapter of the Exploring the Northern Rocky Mountains Field Guide includes new
geologic maps and geomorphic analyses that demonstrate preexisting structural controls on surface
rupture patterns along the Madison Range and Hebgen Lake-Red Canyon fault systems.
July 21, 2014
GECSC Geologist Ren Thompson and Tien Grauch of the
USGS Crustal Geophysics and Geochemistry Science Center served as instructors and regional experts
for a NASA astronaut training exercise in the application of geophysics and geologic mapping to
field investigation of the volcano-tectonic evolution of the northern Rio Grande rift. Eight
students of the current NASA astronaut candidate class were immersed in field studies from July
14-18 in the Rio Grande del Norte National Monument of northern New Mexico. This exercise was
coordinated by NASA, in cooperation with the USGS, the New Mexico Bureau of Geology and Mineral
Resources, the Bureau of Land Management, and a number of academic research institutions.
July 15, 2014
Harvest estimates and economic valuation
of native consumption of Northern Pintails (Anas acuta) in Arctic and sub-Arctic North
By Joshua Goldstein, Wayne Thogmartin, Ken Bagstad (GECSC), James Dubovsky, Brady
Mattsson, Darius Semmens (GECSC), Laura López-Hoffman, and Jay Diffendorfer (GECSC).
Published in Human Dimensions of Wildlife.
In this case study, regional and sub-regional
economic values of subsistence pintail harvests by indigenous communities in Arctic U.S. and Canada
were quantified using the replacement cost method, which compares the cost of the most similar
store-bought replacement for hunted duck meat. For an estimated annual subsistence harvest of
~15,000 pintail, a mean estimate for the total replacement cost was ~$63,000/year (in 2010 USD),
with sub-regional values ranging from $263/year to $21,930/year. These results provide an
order-of-magnitude, conservative estimate of one component of the regional ecosystem-service values
of pintails while presenting spatially explicit values that can inform migratory species
July 7, 2014
From theoretical to actual ecosystem services:
Accounting for beneficiaries and spatial flows in ecosystem service assessments
Bagstad (GECSC), Ferdinando Villa, David Batker, Jennifer Harrison-Cox, Brian Voigt, and Gary
Johnson. Published in Ecology and Society.
New ecosystem services modeling approaches that
map and quantify service-specific sources, sinks, users, and spatial flows can provide a more
complete understanding of ecosystem services than the approaches that solely map ecosystems'
capacity to provide a service (i.e., sources). This article presents results of a case study
conducted in the Puget Sound in Washington that aimed to quantify and differentiate between the
theoretical provision of services and their actual provision using this newer method. The service
supply, demand, and flow of five ecosystem services were mapped using the ARIES methodology, with the outcome showing the importance of
mapping flow paths between people and ecosystems when mapping ecosystem services.
July 2, 2014
distributions across chaparral habitats exposed to wildfire and rural housing in southern
By Paul Schuette, Jay Diffendorfer (GECSC), Doug Deutschman, Scott Tremor, and
Wayne Spencer. Published by International Journal of Wildland Fire.
Few data exist to
evaluate the effects of fire and anthropogenic pressures on plant and animal communities found in
chaparral and coastal sage scrub habitats. To address this knowledge gap, detection-non-detection
data was collected to measure carnivore (coyote, gray fox, bobcat, and striped skunk) occupancy
patterns following a 2003 wildfire in San Diego County, California. The occupancy patterns revealed
have potential use as baseline data to inform fire management policy and wildlife management
strategies in similar fire-prone ecosystems.
July 1, 2014
map of the Granite 7.5' quadrangle, Lake and Chaffee Counties, Colorado
By Ralph Shroba,
Karl Kellogg, and Ted Brandt. U.S. Geological Survey Scientific Investigations Map 3294.
1:24,000-scale map describes the geology of the Granite 7.5' quadrangle in the upper Arkansas
valley, along the lower flanks of the Sawatch Range and Mosquito Range, of central Colorado. Along
with the geologic map (with and without lidar hillshade) and accompanying report, GIS data files of
the mapped area are available for download.
June 30, 2014
Ocean-atmosphere forcing of centennial
hydroclimate variability in the Pacific Northwest
By Byron Steinman, Mark Abbott, Michael
Mann, Joseph Ortiz, Song Feng, David Pompeani, Nathan Stansell, Lesleigh Anderson (GECSC), Bruce
Finney and Broxton Bird. Published in Geophysical Research Letters.
This paper presents
sediment oxygen isotope records spanning the last two millennia from 10 lakes, as well as climate
model simulations, indicating that the Little Ice Age was dry relative to the Medieval Climate
Anomaly in much of the Pacific Northwest of North America. The findings utilized a network of
oxygen isotope records in the Western U.S, including those that GECSC Geologist Lesleigh Anderson
developed from Jellybean Lake and Marcella Lake in the Yukon Territory, Canada.
June 19, 2014
Mapping Mountain Pine Beetle Mortality through Growth
Trend Analysis of Time-Series Landsat Data
By Lu Liang, Yanlei Chen, Todd Hawbaker
(GECSC), Zhiliang Zhu, and Peng Gong. Published in Remote Sensing.
In recent decades, the
forests of western North America have experienced an extensive mountain pine beetle outbreak.
Monitoring the spread of the outbreak has been challenging, and remote sensing could be used to
generate data needed for long-term monitoring. This article presents a method for such monitoring
that integrates Landsat temporal trajectories and decision tree techniques to derive annual forest
disturbance maps over an 11-year period in Grand County, Colorado. Overall accuracy of our results
ranged between 87 and 94% depending on the year, but was much higher than accuracies from
single-date image classifications which ranged between 37 and 75%. Our approach requires minimal
training data and could be used to detect and attributing disturbances in other, but similar
June 19, 2014
Modeling erosion of ice-rich permafrost bluffs
along the Alaskan Beaufort Sea coast
By Katherine Barnhart, Robert Anderson, Irina
Overeem, Cameron Wobus, Gary Clow (GECSC), and Frank Urban (GECSC). Published in Journal of
Geophysical Research: Earth Surface.
Along Alaska's Beaufort Sea coast, erosion rates have
increased roughly threefold from 6.8 to 19 meters per year since 1955 while the sea ice-free season
has increased roughly twofold from 45 to 100 days since 1979. Presented in this paper is a numerical
model of bluff retreat to assess the relative roles of the length of sea ice-free season, sea level,
water temperature, nearshore wavefield, and permafrost temperature in controlling erosion rates in
June 18, 2014
Geologist Frank Urban contributed coastal erosion
footage from Drew Point, Alaska to the National Geographic television program "COSMOS: A Spacetime Odyssey" (Episode 12). Using the footage
as an example, host Neil deGrasse Tyson explains how we can witness the effects of global warming in
the acceleration of erosion of Alaska's northern shore. The collection of this time-lapse imagery is
a component of the Real-Time Permafrost and
Climate Monitoring Network - Arctic Alaska.
June 17, 2014
Methodological improvements in U.S.
state-level Genuine Progress Indicators: Towards GPI 2.0
By Ken Bagstad (GECSC),
Günseli Berik, and Erica J. Brown Gaddis. Published in the journal Ecological Indicators.
The Genuine Progress Indicator (GPI) has emerged as an important monetary measure of economic
well-being that takes into account the benefits and costs of economic production across diverse
domains in a more comprehensive manner than the widely cited Gross Domestic Product. In this study,
the "state of the art" in recent US state-level GPI studies is reviewed and diverging methods, which
have reduced comparability between studies and resulted in varying methodological sophistication,
are identified. These differences in method and application will need to be successfully addressed
and disseminated in order to create a "GPI 2.0" that measures economic well-being with greater
consistency, accuracy, and policy relevance than past GPI measurements.
June 12, 2014
Validating a method for transferring
social values of ecosystem services between public lands in the Rocky Mountain region
Ben Sherrouse and Darius Semmens. Published in Ecosystem Services.
Social values (perceived
values that the public ascribes to ecosystem services) can enhance ecosystem service assessments
when considered alongside economic and ecological values. Social-values data can be elicited through
value and preference surveys; however, various limitations prevent their regular collection. These
limitations led to the use of Social Values for Ecosystem
Services (SolVES) to demonstrate an approach for applying benefit transfer, a
nonmarket-valuation method, to spatially explicit social values. Performance was evaluated through
comparisons of social-value maps estimated by models transferred from external study areas with
those generated from local survey data. It was found that performance varied with the number and
type of environmental variables used, as well as differences in the study areas' physical and social
contexts. Results suggest that enhanced metadata and better social-context matching could improve
June 11, 2014
Pluvial lakes in the Great Basin of the
western United States—A view from the outcrop
By Marith Reheis (GECSC), Kenneth
Adams, Charles Oviatt, and Steven Bacon. Published in Quaternary Science Reviews.
invited review paper discusses how outcrops and landforms in the Great Basin can potentially yield
long climate records and provide direct evidence of lake level, as opposed to the study of lake
sediment cores which rely on proxy interpretation. Outcrop-based studies of lake level changes and
drainage-basin histories are reviewed and summarized, and lake-level records compared to proxy core
records for some lakes. The paper concludes with the suggestion that research on a pluvial lake
should incorporate and synthesize both core and outcrop studies for a more complete record.
June 9, 2014
Natural uranium and strontium isotope tracers
of water sources and surface water-groundwater interactions in arid wetlands—Pahranagat
Valley, Nevada, USA
By Jim Paces (GECSC) and Frederic Wurster. Published in the Journal
The study emphasizes the use and benefits of heavy radiogenic isotopes of Sr
and U to identify unique sources of groundwater and surface water in a modern arid wetland. Those
data allow a simple means of understanding hydrologic mixing processes in a complex geochemical
environment that would be very difficult to evaluate based on more conventional chemical and
June 6, 2014
Iron oxide minerals in dust of the Red Dawn
event in eastern Australia, September 2009
By Rich Reynolds (GECSC), Stephen Cattle,
Bruce Moskowitz, Harland Goldstein (GECSC), Kimberly Yauk , Cody Flagg, Thelma Berquó,
Raymond Kokaly, Suzette Morman, and George Breit. Published in Aeolian Research.
minerals are an important component in atmospheric dust. Ferric oxides have the capacity to absorb
solar radiation thereby changing weather and climate, and ferrous oxides are considered to be the
major source of iron for ocean fertilization, with potentially important effects on draw-down of
atmospheric carbon dioxide. In this study of iron oxide minerals in dust across eastern Australia
from the massive Red Dawn dust storm of September 23, 2009, nano-size ferric oxides, hematite and
goethite, are ubiquitous and are associated with very low reflectance of solar radiation, based on
laboratory measurements. Magnetite (a mixed ferric-ferrous oxide) occurs in Red Dawn dusts collected
in and around Sydney, leading to the inference that anthropogenic ferrous iron was carried in the
dust eastward to the Tasman Sea, with potential to induce fertilization of phytoplankton.
May 30, 2014
Temperature data acquired from the DOI/GTN-P
Deep Borehole Array on the Arctic Slope of Alaska, 1973-2013
By Gary Clow. Published in
Earth Systems Science Data.
This report presents a 40-yr record of permafrost temperatures
acquired by the USGS from the DOI/GTN-P Deep Borehole Array on the Arctic Slope of Alaska. This is
the largest array of deep (> 125 m) boreholes in the world used to monitor the thermal state of
permafrost, one of the Essential Climate Variables monitored by the Global Climate Observing System
(GCOS). The Global Terrestrial Network for Permafrost (GTN-P), of which DOI/GTN-P is a part, is one
of several global terrestrial networks contributing to GCOS. In addition to documenting the rapidly
changing state of permafrost in arctic Alaska, the data will be useful for refining our basic
understanding of the physical conditions occurring in permafrost in this region, as well as
providing important information for validating predictive models used for climate impact
May 22, 2014
Geospatial optimization of siting large-scale
solar energy projects [PDF]
By Jordan Macknick, Ted Quinby, Emmet Caulfield, Margot
Gerritsen, Jay Diffendorfer (GECSC), and Seth Haines. Published by the Joint Institute for Strategic
The siting of utility-scale solar projects can be complex, with
environmental, social, and economic factors needing to be evaluated. This report describes a
proof-of-concept, Web-based Geographical Information Systems (GIS) tool that evaluates multiple
user-defined criteria in an optimization algorithm to inform discussions and decisions regarding the
locations of such projects. The tool improves upon the existing siting guidelines by being
user-driven, transparent, interactive, and capable of incorporating multiple criteria.
May 21, 2014
Biologic effects of desert dust in
respiratory epithelial cells and a murine model
By Andrew Ghio, Suryanaren Kummarapurugu,
Haiyan Tong, Joleen Soukup, Lisa Dailey, Elizabeth Boykin, Ian Gilmour, Peter Ingram, Victor Roggli,
Harland Goldstein (GECSC), and Rich Reynolds (GECSC). Published in Inhalation Toxicology.
This study, a collaboration between USGS, U.S. Environmental Protection Agency, and Duke
University researchers, tested the postulate that desert dust collected in the southwestern United
States imparts a biological effect in respiratory epithelial cells. The results show that the desert
dusts, despite containing low concentrations of pure silica, provoked biologic effects similar to
those imparted by pure silica dust, which is known to cause severe biologic damage. The samples used
in the test are representative of the annual dust transport from major dust-source regions on the
Colorado Plateau to and beyond Colorado's heavily populated Front Range.
May 20, 2014
Research Ecologist Jenny Briggs is featured in Career gaps: Maternity
muddle, a Nature online article about the challenges (and some solutions) surrounding
maternity/paternity leave and the early years of childrearing for research scientists. In the story
Jenny describes strategies she employed for maintaining annual field research in the forests of
Colorado after having her second child Iris. Also featured in the article is former GECSC employee
Yarrow Axford, who discusses how she managed her research work at Northwestern University in
Evanston, Illinois, after the birth of her son. Contributors to the article highlighted the
important support they received from employers, colleagues, and family.
May 16, 2014
Effect of sulfate and carbonate minerals on
particle-size distributions in arid soils
By Dirk Goossens, Brenda Buck, Yuanxin Teng,
Colin Robins, and Harland Goldstein (GECSC). Published in Soil Science Society of American
The presence of water-soluble salt minerals, which are common in arid soils, can
affect the results of particle-size analyses. This study investigates the effects of salt minerals
on particle-size analysis by comparing analyses in water, in which the minerals dissolve, and
isopropanol, in which they do not. The results show that more accurate particle-size distributions
for arid soils containing water-soluble minerals can be obtained through analysis using liquids in
which the mineral grains do not dissolve.
May 9, 2014
As part of his work on the "Rates of Recent Warming in
Arctic Alaska as Detected by the DOI/GTN-P Observing Network" project, GECSC Geologist Frank Urban
recently installed two new real-time cameras near the USGS/Bureau of Land Management camp at Inigok, Alaska. The new cameras (Camera 1, Camera 2)
communicate to a USGS base station at Inigok via a radio telemetry link and will be used to support
the Circum-Arctic Lakes Observation Network (CALON) lake
monitoring efforts as well as provide additional imagery for air and field logistics at Inigok.
April 29, 2014
Three-dimensional geologic mapping of the Cenozoic
basin fill, Amargosa Desert basin, Nevada and California
By Emily Taylor and Don
Sweetkind. Published as USGS Scientific Investigations Report 2014-5003.
subsurface geologic framework of the Cenozoic basin fill that underlies the Amargosa Desert in
southern Nevada and southeastern California has been improved by using borehole data to construct
three-dimensional lithologic and interpreted facies models. The lithologic model presented in this
report portrays a complex system of interfingered coarse- to fine-grained alluvium, playa and
palustrine deposits, eolian sands, and interbedded volcanic units. Accompanying the report is the
April 24, 2014
GECSC Geologist Lesleigh Anderson is quoted in
several publications about a soon to be published study titled "Paired oxygen isotope records reveal modern North
American atmopsheric dynamics during the Holocene" in Nature Communications that utilizes
Lesleigh's isotope record from Jellybean
Lake in the Yukon Territory, Canada. In three seperate articles Lesleigh discusses how the new
study highlights the value of the paleoclimate data as historical context for modern jet stream
behavior. She went on to say that mechanisms that drive long-term jetstream behavior are difficult
to precisely indentify but that phenomena like El Niño and the Pacific Decadal Oscillation
also appear to undergo long-term shifts that are only evident from long paleoclimatic records. Her
comments can be found in "Frigid Eastern Winters
and Warm Western Ones Nothing New—Blame the Jet Stream" (E&E Publishing), "Frigid Winter? Blame
4,000 Years of Wild Jet Streams" (LiveScience), and "Hot
West, Cold East May be the Norm as World Warms" (Climate Central).
April 18, 2014
The USGS Unmanned Aircraft System (UAS) Project
Office was involved in the recent test run of using unmanned arial technology to survey elk in
dense, forested areas in the Skagit Valley of Washington. The mission, done in cooperation with the
Bureau of Land Management, the Bureau of Indian Affairs, and Western Washington University, was
reported on in the articles "New elk survey takes flight" and "Drones plot upriver elk herd's size". The project's
purpose is also discussed in the Western Washington University video "
Professor, students use UAVs to track elk herds". The UAS Project Office provided and operated
the battery-powered Raven aircraft for the survey.
GECSC Geologist Lesleigh Anderson is quoted in the LiveScience article Despite Warming, Ground
Refreezes at Alaska's Shrinking Lakes. This story describes a recent study led by Martin Briggs
and other USGS scientists that reports on new permafrost forming around a shrinking lake in Alaska's
interior. Lesleigh explains how her 2013 study of the lake's
lower water levels can be attributed to less precipitation and more evaporation that may be a
reflection of normal Pacific climate cycles that affect the region. Together the two studies
provide new insights into the dynamics between climate, surface water and permafrost in Alaska.
April 16, 2014
Ecosystem services are the benefits that nature
provides to human well-being—from clean air and water, protection from natural disasters,
fisheries, crop pollination and control of pests and disease, and outdoor places for recreation,
solitude, and renewal. The Ecosystem Services
Assessment and Valuation (ESAV) project's new website gives an overview of research underway by
the ESAV team, such as the study of spatial subsidies for migratory species, resource management on
public lands, and the development and use of ecosystem services tools.
April 15, 2014
The GECSC NLCD team (Cartographer Catherine Costello,
Cartographer Rick Poss, and Physical Scientist Lori Baer) produced about one third of the dataset
found in the newly released 2011 edition of the National
Land Cover Database (NLCD). The purpose of the database, a product of the Multi-Resolution Land Characteristics Consortium, is to provide
complete, current, consistent, and public domain information on the Nation's land cover. The NLCD
team is currently working on updating the database to include Alaska, which is scheduled to be
published in December 2014.
April 2, 2014
The collaborative work of GECSC Geologist Frank Urban
and Irina Overeem of the University of Colorado, Boulder, is highlighted in Earth Magazine's April
cover story "
Scientists go to extremes to monitor Arctic permafrost loss". Monitoring of Alaska's northern
coast reveals that the increasingly rapid coastal erosion is a consequence of rising air
temperature, which decreases the amount of shoreline-protecting sea ice, thereby exposing permafrost
to relatively warmer seawater and waves for longer periods. This article follows several other
publications as well as a National Oceanic Partnership Program Excellence in Partnering award.
April 1, 2014
A methodology for adaptable and robust
ecosystem services assessment
By Ferdinando Villa, Ken Bagstad (GECSC), Brian Voigt, Gary
Johnson, Rosimeiry Portela, Miroslav Honzák, and David Batker. Published in PLoS ONE.
Ecosystem services are an established conceptual framework for attributing value to the benefits
that nature provides to humans. As the promise of robust ecosystem services-driven management is put
to the test, shortcomings in our ability to accurately measure, map, and value ecosystem services
have surfaced. This article introduces an integrated ecosystem services modeling methodology, named
ARIES (ARtificial Intelligence for Ecosystem Services), which aims to introduce improvements on
March 25, 2014
Evaluation of Pleistocene groundwater flow
through fractured tuffs using a U-series disequilibrium approach, Pahute Mesa, Nevada, USA
By Jim Paces (GECSC), Paul Nichols, Leonid Neymark, and Harihar Rajaram. Published in Chemical
Groundwater flow through fractured felsic tuffs and lavas at the Nevada National
Security Site represents the most likely mechanism for transport of radionuclides away from
underground nuclear tests at Pahute Mesa. To help evaluate fracture flow and matrix-water exchange,
this study determined U-series isotopic compositions on more than 40 drill core samples from 5
boreholes that represent discrete fracture surfaces, breccia zones, and interiors of unfractured
core. It was found that U-series isotopes record evidence for water/rock interaction caused by
groundwater flow through fractures in volcanic rocks. The method used in this study could
potentially identify areas within the saturated zone that represent zones of greater or lesser
groundwater flow, the nature of geochemical processes affecting U mobility and transport, and the
likelihood of whether or not rock matrix is likely to contribute to retardation or dispersion of
constituents of contaminant plumes.
March 21, 2014
Desert wetlands in the geologic
By Jeff Pigati (GECSC), Jason Rech, Jay Quade, and Jordon Bright. Published in
Desert wetlands are relatively common in arid environments worldwide
and form where water tables approach or breach the ground surface. Over time, sediments become
trapped in wetlands by a combination of wet ground conditions and dense plant cover. If properly
recognized, wetland deposits can provide an important source of hydrologic and climatic information.
This paper presents an overview of some of the physical and geochemical characteristics, microfauna
assemblages, and sedimentologic features that can be used to identify wetlands in the geologic
record, and suggests further avenues of research related to these unique hydrologic systems.
March 19, 2014
map of the Sunshine 7.5' quadrangle, Taos County, New Mexico
By Ren Thompson (GECSC),
Kenzie Turner (GECSC), Ralph Shroba (GECSC), Michael Cosca, Cal Ruleman (GECSC), John Lee, and Ted
Brandt (GECSC). Published as USGS Scientific Investigations Map 3283.
This 1:24,000 scale map
describes the geology of the Sunshine 7.5-minute quadrangle, which is located in the south-central
part of the San Luis Basin of northern New Mexico, in the Rio Grande del Norte National Monument.
This region contains deposits that record volcanic, tectonic, and associated alluvial and colluvial
processes over the past four million years. Along with the geologic map are downloadable GIS data
files of the mapped area.
March 19, 2014
map of the Ute Mountain 7.5' quadrangle, Taos County, New Mexico, and Conejos and Costilla Counties,
By Ren Thompson (GECSC), Kenzie Turner (GECSC), Ralph Shroba (GECSC), Michael
Cosca, Cal Ruleman (GECSC), John Lee, and Ted Brandt (GECSC). Published as USGS Scientific
Investigations Map 3284.
This 1:24,000 scale map describes the geology of the Ute Mountain
7.5-minute quadrangle, which is located to the north of the adjacent Sunshine 7.5' quadrangle (USGS Scientific Investigations Map 3283). Ute Mountain
has the distinction of being one of the largest intermediate composition eruptive centers of the
Taos Plateau, a largely volcanic tableland occupying the southern portion of the San Luis Basin.
Along with the geologic map are downloadable GIS data files of the mapped area.
March 14, 2014
GECSC Ecologist Jay Diffendorfer was interviewed by
Boise State Public Radio for their report "
Interactive Map Pinpoints Idaho, U.S. Wind Turbines". Jay discussed the USGS WindFarm Mapping Application, a tool created to
assess the impact of wind energy development on wildlife, which in Idaho would pertain to such
species as raptors, bats and sage grouse. The data from this application has also found use by the
Department of Defense, which is using it to study to assess the impact of wind farms on radar
March 13, 2014
representation of oil and natural gas well pad scars in southwest Wyoming
By Steve Garman
and Jamie McBeth. USGS Data Series 800.
This online report presents a baseline digital
representation of oil and gas well pad scars in the Wyoming Landscape Conservation Initiative study
area, for use in wildlife habitat assessments, and more generally, in assessments of land-use
trends. Up until now, a digital representation of this surface-disturbance feature within what is a
significant portion of the remaining intact sagebrush steppe in the country, has been limited. The
report contains a 7-page pamphlet and downloadable shapefiles for use with GIS applications.
March 12, 2014
Applying Threshold Concepts to Conservation
Management of Dryland Ecosystems: Case Studies on the Colorado Plateau
By Matthew Bowker,
Mark Miller, Steve Garman (GECSC), and Travis Belote. Chapter seven of Application of Threshold Concepts in Natural
Resource Decision Making.
Threshold behaviors describe how a trigger, or sequence of
triggers, may lead to distinct changes within an ecosystem. An ideal monitoring program would
quantify key triggers and be able to inform managers when their measurements indicate an approaching
threshold crossing. Early warning of an approaching threshold crossing enables managers to formulate
actions to avoid irreversible ecosystem decline. This report offers a flexible means for identifying
these triggers, and presents the results of a data-rich case study in Canyonlands National Park and
a data-poor case study in Wupatki National Monument.
February 11, 2014
Market forces and technological
substitutes cause fluctuations in the value of bat pest-control services for cotton
Laura López-Hoffman, Ruscena Wiederholt, Chris Sansone, Ken Bagstad (GECSC), Paul Cryan, Jay
Diffendorfer (GECSC), Joshua Goldstein, Kelsie LaSharr, John Loomis, Gary McCracken, Rodrigo
Medellín, Amy Russell, and Darius Semmens (GECSC). Published in PLOS ONE.
explores the effects of market forces and substitutes on ecosystem service values by assessing how
the value of the pest-control services provided by Mexican free-tailed bats to cotton producers in
the United States has changed over time. The data from 1990 through 2008 shows that the ecosystem
service value of the bats provided to cotton producers declined by 79% due to the widespread
adoption of Bt cotton, which is transgenically modified to express its own pesticide, plus declines
in the market price of cotton. However, with the possible evolution of pest resistance to Bt cotton,
the value of bat pest-control services may increase again, giving rise to an economic option value
argument for conserving Mexican free-tailed bat populations.
February 7, 2014
Unmanned Aircraft Systems (UAS) Project Manager
Mike Hutt and Cartographer Jeff Sloan are quoted in the O'Reilly Radar article "Drone on: UAVs will rule the skies (unless the
FAA says otherwise)". In the story Mike presents the example of a mapping project in White Sands
National Monument that benefitted from the use of UAS, specifically the high resolution imagery they
were able to obtain over the project area. The cost benefits to using this technology, project
challenges, as well as increased use of UAS by research organizations are also discussed.
February 3, 2014
Created and hosted at the GECSC, the new Interior Geospatial Emergency Management System (IGEMS) website
offers the public and emergency management communities online maps containing the latest available
information on earthquakes, earthquake shakemaps, streamflow data, floods, volcanoes, wildfires, as
well as information on severe weather hazards. This site replaces the Natural Hazards Support System
(NHSS), which was one of the first public applications to provide an integrated approach in
incorporating a wide range of hazards into a dynamic mapping environment. Since IGEMS uses the
latest software and technology, it provides functionality beyond that of the NHSS system, including
support for mobile devices such as tablets and smartphones.
January 31, 2014
The role of dust storms in atmospheric particle
concentrations at two sites in the western U.S.
By Jason Neff, Rich Reynolds (GECSC),
Seth Munson, Dan Fernandez, and Jayne Belnap. Published in the Journal of Geophysical Research.
This study presents two continuous records of total dust flux (all particle sizes) from sites in
Colorado and Utah and compares these records to measured dust fluxes for small size ranges less than
10 and 2.5 micrometers (PM10 and PM2.5) made from adjacent samplers. These small dust particles
receive much attention because of their roles in affecting climate and their multiple effects on
human health. Nevertheless, larger particles in atmospheric dust are also common, even far from
their sources in dryland areas. The study found that (1) extreme air pollution across the American
West can be caused by high concentrations of desert dust (all particle sizes) carried by regional
wind storms, (2) standard air-quality measurements (PM2.5 and PM2.5-10), measured by USEPA and NPS,
do not capture the large majority of particulate pollution in this region, and (3) total dust
concentrations in this region are very similar to dust concentrations measured near the large
deserts of Asia and Africa. The study contradicts recently published interpretations about sources
of dust-pollution the American West (wrongly attributed to far-traveled Asian dust), and it thereby
can be taken to counter policy recommendations that are based on inadequate recognition of North
American dust sources.
January 24, 2014
climate and active-layer data acquired in the National Petroleum Reserve-Alaska and the Arctic
National Wildlife Refuge, 1998-2011
By Frank Urban and Gary Clow. U.S. Geological Survey
Data Series 812.
This online report provides over ten years of air temperature, wind speed,
wind direction, ground temperature, soil moisture, snow depth, rainfall, up- and downwelling
shortwave radiation, and atmospheric pressure data collected by the Department of the Interior's
climate monitoring array, part of the Global Terrestrial Network for Permafrost. In addition to
presenting data, this report also describes monitoring, data collection, and quality control
methodology. The data collection is ongoing and done in close collaboration with the Bureau of Land
Management and the U.S. Fish and Wildlife Service.
January 22, 2014
δ87Sr in peat as tracers of paleosalinity in the Sacramento-San Joaquin Delta of
By Judith Drexler, Jim Paces (GECSC), Charles Alpers, Lisamarie
Windham-Myers, Leonid Neymark, Thomas Bullen, and H.E. Taylor. Published in Applied
This study represents a major effort to understand changes in salinity in the
Sacramento-San Joaquin Delta coastal wetland over the last 6,000 years. By looking at the natural
radiogenic isotopes of uranium and strontium as tracers of the hydrologic contributions from
seawater and the two fluvial sources, it was found that the eastern Delta was consistently supplied
with freshwater over this time, but that the western Delta alternated between fresh and brackish
conditions. The largest shifts in salinity are associated with development of agricultural and
mining activities starting in the late 1800s; however, post 1960s data indicate a trend toward
fresher, pre-development conditions.
January 17, 2014
Land-Use and Land-Cover Change in Three Corn Belt
Ecoregions: Similarities and Differences
By Roger Auch, Chris Laingen, Mark Drummond
(GECSC), Kristi Sayler, Ryan Reker, Michelle Bouchard, and Jeffery Danielson. Published in Focus on
While corn can be found nearly uninterrupted across the Midwestern Corn Belt
region, differences in pre-settlement land cover and other biophysical conditions led the U.S.
Environmental Protection Agency to identify three distinct ecological regions: the Eastern Corn Belt
Plains, the Central Corn Belt Plains, and the Western Corn Belt Plains. This study examined the
differences in land cover trends across these ecoregions between 1973 and 2000 using Landsat
satellite imagery, socioeconomic data, fieldwork, and a random sampling approach. Results show that
land use categorical changes vary by ecoregion with the westernmost zone showing the most temporary
changes as grassland and agriculture fluctuated in response to government policies and economic
opportunities. The leading type of landscape change in the eastern and central zones was the
conversion of agricultural land cover to developed (urban) land.
January 14, 2014
Uranium-series ages of corals, sea level
history, and palaeozoogeography, Canary Islands, Spain: An exploratory study for two Quaternary
By Dan Muhs (GECSC), Joaquín Meco, and Kathleen Simmons
(GECSC). Published in Palaeogeography, Palaeoclimatology, Palaeoecology.
presents the first ever uranium-series dates obtained from fossilized marine deposits found on the
Canary Islands. The ages for two records that show a sea level considerably higher than today
occurred at roughly 481,000 years ago and at about 130,000-120-000 years ago. Mollusk remains in the
deposits also provide clues about the surrounding ocean temperature at the time when they were
created, which appears to have had warmer-than-modern sea surface temperatures.
January 13, 2014
Mountain pine beetle impacts on vegetation and carbon
By Todd Hawbaker, Jenny Briggs, Megan Caldwell, and Susan Stitt. U.S. Geological
Survey Fact Sheet 2013-3095
In the Southern Rocky Mountains, an epidemic outbreak of mountain
pine beetle has caused levels of tree mortality unprecedented in recorded history. The impacts of
this mortality on vegetation composition, forest structure, and carbon stocks have only recently
received attention, although the impacts of other disturbances such as fires and land-use/land-cover
change are much better known. This study integrates field-collected data with vegetation simulation
models to assess and quantify how long-term patterns of vegetation and carbon stocks have and may
change in response to mountain pine beetle outbreaks and other disturbances.
December 24, 2013
Simulated impacts of mountain pine beetle and
wildfire disturbances on forest vegetation composition and carbon stocks in the Southern Rocky
By Megan Caldwell (GECSC), Todd Hawbaker (GECSC), Jenny Briggs (GECSC), Paul
Cigan, and Susan Stitt (GECSC). Published in Biogeosciences.
In the Rocky Mountains of
eastern Grand County, Colorado, a recent mountain pine beetle outbreak caused remarkable levels of
tree mortality. To evaluate the long-term impacts of both this insect outbreak and another
characteristic disturbance of these forests, high-severity wildfire, this study used computer
modeling to simulate potential changes in species composition and carbon stocks for these scenarios.
The results show that lodgepole pine forests are largely resilient to disturbances, with the forest
recovering from the insect outbreak in 40-50 years, compared to 70-80 years of recovery time after
December 10, 2013
Loess origin, transport, and deposition over
the past 10,000 years, Wrangell-St. Elias National Park, Alaska
By Dan Muhs (GECSC), Jim
Budahn, Jack McGeehin, Arthur Bettis III, Gary Skipp (GECSC), Jim Paces (GECSC), and Elisabeth
Wheeler. Published in Aeolian Research.
Dust plays an wide-ranging and integral part in
Earth's environmental systems, but dust research has mainly been limited to study of contemporary
dust sources in low-latitude arid regions, or on dust production at higher latitudes during the last
glacial period. In contrast, this study examined a modern, high-latitude glaciogenic dust record
from along Alaska's Copper River, where dust has been accumulating over the past 10,000 years. The
results show that contemporary glaciogenic dust at high latitudes plays an important role in the
overall dust budget, particularly with respect to iron delivery to the world's oceans.
December 2, 2013
GECSC Geologist Sarah Shafer co-authored chapters
3, 4, and 5 in the report Climate Change in the
Northwest: Implications for Our Landscapes, Waters, and Communities published by Island Press.
The report is a regional technical input contribution to the U.S. National Climate Assessment and
has been covered by popular media. The report reviews the current understanding of potential future
climate changes and their effects in Oregon, Washington, and Idaho.
December 2, 2013
Comparing approaches to spatially explicit
ecosystem service modeling: A case study from the San Pedro River, Arizona
By Ken Bagstad
(GECSC), Darius Semmens (GECSC), and Robert Winthrop. Published in Ecosystem Services.
study compares results obtained from two leading open-source ecosystem services modeling tools,
ARIES and InVEST, when applied to a project in the San Pedro River watershed on the U.S.-Mexico
border. Locally important services that both modeling systems could address—carbon, water, and
scenic viewsheds—were modeled. It was found that results were more closely aligned for
landscape-scale urban-growth scenarios and more divergent for a site-scale mesquite-management
November 27, 2013
Chronology and provenance of last-glacial
(Peoria) loess in western Iowa and paleoclimatic implications
By Dan Muhs (GECSC), Arthur
Bettis III, Helen Roberts, Stephen Harlan, Jim Paces (GECSC), and Rich Reynolds (GECSC). Published
in Quaternary Research.
Modeling suggests that the increased dustiness Earth experienced
during the last glacial period was due to generally stronger, more frequent winds. This study tested
that model by creating a chronology of the loess deposits found in Loveland, Iowa—one of the
thickest such deposits from last-glacial-age found in the world. The findings confirmed that
increased dustiness during the last glacial period was driven largely by enhanced gustiness, forced
by a steepened meridional temperature gradient.
November 25, 2013
Evaluation of Pleistocene groundwater flow
through fractured tuffs using a U-series disequilibrium approach, Pahute Mesa, Nevada, USA
By Jim Paces (GECSC), Paul Nichols, Leonid Neymark, and Harihar Rajaram. Published in Chemical
Groundwater flow through fractured felsic tuffs and lavas at the Nevada National
Security Site represents the most likely mechanism for transport of radionuclides away from
underground nuclear tests at Pahute Mesa. The methods employed for this study found that many Pahute
Mesa fractures represent stable hydrologic pathways over million-year timescales. Furthermore, these
methods can potentially identify areas within the saturated zone that represent zones of greater or
lesser groundwater flow, the nature of geochemical processes affecting U mobility and transport, and
the likelihood of whether or not rock matrix contributes to retardation or dispersion of
constituents of contaminant plumes.
November 18, 2013
Accumulation of Organic Carbon-Rich Strata along
the Western Margin and in the Center of the North American Western Interior Seaway during the
By Walt Dean (GECSC), Erle Kauffman, and Michael Arthur.
Published as Chapter 3 of At the Top of the Grand Staircase: The Late Cretaceous of Southern Utah,
published by Indiana University Press.
A core of the mid-Cretaceous organic-carbon-rich
Tropic Shale was collected near the Town of Escalante in western Utah. The Tropic is really a
marlstone with up to 60% CaCO3. The Tropic is the time equivalent of the Bridge Creek
Limestone in eastern Colorado and Kansas. Geochemical analyses of samples from the Escalante core
have enabled us to correlate individual peaks of CaCO3 with limestone beds in the Bridge
November 18, 2013
Climate change's impact on key ecosystem services and
the human well-being they support in the US
By Erik Nelson, Peter Kareiva, Mary
Ruckelshaus, Katie Arkema, Gary Geller, Evan Girvetz, Dave Goodrich, Virginia Matzek, Malin Pinsky,
Walt Reid, Martin Saunders, Darius Semmens (GECSC), and Heather Tallis. Published in Frontiers in
Ecology and the Environment.
Climate models portend continued warming and more frequent
extreme weather events across the United States. This paper discusses some of those observed and
anticipated impacts on food production, wildfire management, coastal development, recreation, and
water availability. It is proposed that government agencies, private companies, and nongovernmental
organizations can assess and prioritize possible ecosystem service-based adaptations to change
through a natural capital and assets "balance sheet" framework.
November 15, 2013
Moving across the border: modeling migratory bat
By Ruscena Wiederholt, Laura López-Hoffman, Jon Cline, Rodrigo Medellin,
Paul Cryan, Amy Russell, Gary McCracken, Jay Diffendorfer (GECSC), and Darius Semmens (GECSC).
Published in Ecosphere.
Knowledge and conservation of bat migratory routes is critical in the
face of increasing threats from climate change and wind turbines that might decrease migratory
survival. This article presents the results of a study that employed a new modeling approach for
Mexican free-tailed bat migration that simulates migratory routes between winter habitat in southern
Mexico and summer breeding roosts in northern Mexico and the southwestern United States. This
network modeling approach contributes to conservation efforts by identifying those breeding roosts
most influential to the overall bat population, and can be used as a tool to improve our
understanding of bat migration for other species.
November 15, 2013
The Mountain Town News article After the haul of big
Ice Age bones, the Snowmass takeaways more difficult reports on some of the findings that GECSC
Geologists Jeff Pigati and Laura Strickland presented at the Geological Society of America meeting
in October. The dig at Snowmass Village, Colorado in 2011 uncovered an unusual amount of extinct
megafauna fossils as well as fossils of smaller animals and the remains of plants and pollen. Jeff
and Laura shared the results of their work that they did on the site, giving details about the
environment and climate as it existed there tens of thousands of years ago.
November 8, 2013
National valuation of monarch butterflies indicates
an untapped potential for incentive-based conservation
By Jay Diffendorfer (GECSC), John
Loomis, Leslie Ries, Karen Oberhauser, Laura Lopez-Hoffman, Darius Semmens (GECSC), Brice Semmens,
Bruce Butterfield, Ken Bagstad (GECSC), Josh Goldstein, Ruscena Wiederholt, Brady Mattsson, and
Wayne Thogmartin. Published in Conservation Letters.
North American monarch butterflies,
whose annual migration is one of the world's most spectacular natural events, have been declining in
number since 1999. This study sought to understand how much, and where, humans place value for a
migratory species that crosses international borders and depends on multiple regions. The results
indicate that U.S. households valued monarchs as a total one time payment of $4.78-$6.64 billion,
levels similar to many endangered vertebrate species. If even a small percentage of the population
acted upon this reported willingness, the cumulative effort would likely translate into a large,
untapped potential for conservation of the iconic butterfly.
November 5, 2013
Constraints on the age of the Great Sand Dunes,
Colorado, from subsurface stratigraphy and OSL dates
By Rich Madole (GECSC), Shannon
Mahan, Joe Romig, Jeremy Havens (GECSC). Published in Quaternary Research.
The age of the
Great Sand Dunes has been debated for nearly 150 years. Precisely when the Great Sand Dunes began to
form is yet to be determined, but this paper presents new information—chiefly subsurface
stratigraphic data, OSL dates, and geomorphic evidence—that indicates that the Great Sand
Dunes began to form in the latter part of the middle Pleistocene, sometime between 440,000 and
130,000 years ago.
November 4, 2013
map of the Mount Sherman 7.5' quadrangle, Lake and Park Counties, Colorado
Bohannon and Cal Ruleman. Published as USGS Scientific Investigations Map 3271.
describes the geology of the Mount Sherman 7.5-minute quadrangle, which is located along the crest
of the Mosquito Range in between Leadville and Fairplay, Colorado. The quadrangle includes eleven
13,000-foot peaks and one fourteener, Mount Sherman. This publication also includes downloadable GIS
data files of the mapped area.
October 31, 2013
Oceanographic controls on sedimentary and geochemical
facies on the Peru outer shelf and upper slope
By Michael Arthur and Walt Dean (GECSC).
Published as U.S. Geological Survey Open-File Report 2013-1105.
characteristics of organic matter in surface sediments deposited under an intense oxygen-minimum
zone on the Peru margin were mapped and studied in samples from deck-deployed box cores and push
cores acquired by submersible on two east-west transects spanning depths of 75 to 1,000 meters at
12°S and 13.5°S. On the basis of sampling and analyses of the top 1–2 cm of available
cores, three main belts of sediments were identified on each transect with increasing depth: (1)
muds on the outer shelf and upper slope that are rich in organic-carbon and the phosphate mineral
apatite; (2) authigenic phosphatic mineral crusts and pavements consisting entirely of apatite; and
(3) glauconite sands at depths >750 m. The phosphorite and glauconite are formed entirely on the sea
floor from preexisting carbonate and (or) detrital clastic sediments. The distribution of
sedimentary geochemical facies on the Peru margin are primarily controlled by oxidation/reduction
conditions and strength of bottom currents.
October 30, 2013
A comparative assessment of decision-support
tools for ecosystem services quantification and valuation
By Ken Bagstad (GECSC), Darius
Semmens (GECSC), Sissel Waage, and Robert Winthrop. Published in Ecosystem Services.
Ecosystem services tools, be they simple spreadsheet models or complex software packages, seek to
identify, characterize, and quantify the benefits that ecosystems provide to people. This study
rates 17 ecosystem services tools against eight evaluative criteria that gauge their readiness for
widespread application in public- and private-sector decision making. This study also describes
potential pathways forward to reduce the resource requirements for running ecosystem services
models, which are essential to facilitate their more widespread use in environmental decision
October 28, 2013
map of Chickasaw National Recreation Area, Murray County, Oklahoma
By Chuck Blome, Dave
Lidke (GECSC), Ron Wahl, and James Golab. Published as U.S. Geological Survey Scientific
Investigations Map 3258.
Prepared in cooperation with the National Park Service, this
1:24,000-scale geologic map is a compilation of previous geologic maps and new geologic mapping of
areas in and around Chickasaw National Recreation Area. The accompanying pamphlet includes
information pertaining to how the geologic units and structural features in the map area relate to
the formation of the northern Arbuckle Mountains and its Arbuckle-Simpson aquifer. Also available
for download are GIS data files of the mapped area.
October 25, 2013
The Ventura County Star interviewed GECSC Geologist
Dan Muhs for the article "
Fossil found on Santa Rosa Island may reveal new information on pygmy mammoths". Dan was
studying marine terraces on Santa Rosa Island, part of Channel Islands National Park, last summer
when he discovered a mammoth tusk among 80,000 year old marine fossils. Mammoth remains have been
found on the Channel Islands before, but this fossil's location indicates that mammoths lived on the
islands much earlier than previously believed.
August 19, 2013
Radiocarbon dating late Quaternary loess
deposits using small terrestrial gastropod shells
By Jeff Pigati (GECSC), Jack McGeehin,
Dan Muhs (GECSC), and Arthur Bettis III. Published in Quaternary Science Reviews.
deposits are an important archive of past environmental and climate conditions, and are one of the
few geologic deposits that contain primary information of past atmospheric circulation patterns and
wind regimes. However, constraining the age of loess is often difficult because of the paucity of
organic material typically available for radiocarbon dating and the inherent limitations of
luminescence techniques. This study shows that 14C dating of small terrestrial gastropod
shells provides a reliable alternative to these techniques for dating late Quaternary loess deposits
in North America.
August 12, 2013
An application of Social Values for Ecosystem
Services (SolVES) to three national forests in Colorado and Wyoming
By Ben Sherrouse
(GECSC), Darius Semmens (GECSC), and Jessica Clement. Published in Ecological Indicators.
SolVES, a GIS tool to assess, map, and quantify nonmarket
values perceived by ecosystem stakeholders, has been extended in version 2.0 with the capability to
generate more complete social-value maps from available survey data and produce more robust models
describing the relationship between social values and ecosystems. Applying SolVES to value and
preference survey data, the study evaluated how effectively its calculations could reproduce results
from more common statistical methods of data analysis, as well as examined how its spatial results
could be used by managers and stakeholders to better understand more complex relationships among
stakeholder values, attitudes, and preferences. The results suggest that SolVES can effectively
reproduce information derived from traditional statistical analyses while adding spatially explicit,
social-value information that can contribute to integrated resource assessment, planning, and
management of forests and other ecosystems.
July 26, 2013
and patterns of off-highway vehicle (OHV) use in remote areas of the western USA [PDF]
Douglas Ouren and Alisa Coffin (GECSC). Published in Oecologia Australis.
popularity of OHV activities has elevated concerns about their ecological effects, the impacts on
wildlife, and the sustainability of OHV use on secondary and tertiary road networks. To better
understand the impacts of this activity on the environment, this study set out to gather information
about OHV use within a study area in Western Colorado. The resulting data shows patterns of the
daily, seasonal, and annual motorized use in this area, as well as types of vehicles driven and the
relative location of observation points within the road network.
July 25, 2013
and Sections of the Holy Cross Quadrangle, Eagle, Lake, Pitkin, and Summit Counties,
By Odgen Tweto. Digital edition and database by Theodore R. Brandt (GECSC).
USGS Miscellaneous Investigations Series Map I-830.
Originally mapped by Ogden Tweto and
published as a printed edition in 1974, the geologic data for Holy Cross 15-minute quadrangle has
been captured digitally for use with GIS applications. These data are presented as ArcGIS
geodatabase, ArcInfo coverage, and ArcView shape files along with images of the printed map sheets.
The map depicts in detail the complex geology at the north end of the Sawatch Range on the west at
its junction with south end of the Gore Range on the east.
July 23, 2013
Tourism values for Mexican free-tailed bat
(Tadarida brasiliensis mexicana) viewing
By Ken Bagstad (GECSC) and Ruscena Wiederholt.
Published in Human Dimensions of Wildlife.
This article summarizes visitation numbers and
economic values for Mexican free-tailed bat wildlife viewing at sites throughout the Southwestern
United States. This sort of rangewide ecosystem service value estimation of a migratory species has
seldom been estimated, but when paired with biological data about species' habitat needs, it can
better inform conservation management and policy decisions.
July 22, 2013
Spatial dynamics of ecosystem service flows: A
comprehensive approach to quantifying actual services
By Ken Bagstad (GECSC), Gary
Johnson, Brian Voigt, and Ferdinando Villa. Published in Ecosystem Services.
ecosystem service flows between ecosystems and their beneficiaries that are not co-located has been
a need of researchers since the problem was first described. This article presents an approach to
fill that need called SPAN (Service Path Attribution Networks), a family of agent-based models used
to map ecosystem service flows, highlighting the spatial connections between source, sink, and use
locations. The article also describes currently implemented SPAN models as well as examples of how
to apply this approach to additional ecosystem services.
July 19, 2013
The Seattle Times article "Northwest Scientists
Using Drones to Spy on Nature" reports on the increased use of unmanned aircraft systems (UAS)
by scientists in their research. Quoted in the article is UAS Project Manager Mike Hutt, who
explains how this increased interest is largely the result of expanded capabilities that came with
an improvement in the aircraft and monitoring technology. Also discussed are the origins of UAS for
scientific research as well as an overview of the technology and its advantages over other data
July 15, 2013
Controls on recent Alaskan lake changes identified
from water isotopes and remote sensing
By Lesleigh Anderson (GECSC), Jean Birks, Jennifer
Rover, and Nikki Guldager. Published in Geophysical Research Letters, volume 40.
the existence and cause of recent lake area changes in the Yukon Flats, a region of discontinuous
permafrost in north central Alaska, this study evaluated remotely sensed imagery with lake water
isotope compositions and hydroclimatic parameters. Evaluation of the collected data revealed not
only the source water of the lakes, but also evaporation rates and rates of water inflow. The
findings indicate that most of these lakes were near their maximum extent in the early 1980s during
a relatively cool and wet period. Subsequent reductions can be explained by moisture deficits and
July 3, 2013
UAS Project Manager Mike Hutt is quoted in the article
Droning on for Science that
appears in the July issue of Earth. Mike gives details about UAS Project Office missions, cost
advantages of using unmanned aerial systems (UAS) over other technologies, as well as the process
for getting authorization to undertake proposed missions. The rest of the article gives an overview
of UAS and how it is being employed for scientific research by various governmental agencies and
June 19, 2013
Identifying buried segments of active faults in the
northern Rio Grande rift using aeromagnetic, LiDAR, and gravity data, south-central Colorado,
By Tien Grauch (USGS Crustal Geophysics and Geochemistry Science Center) and Cal
Ruleman (GECSC). Published in the Journal of International Geophysics.
In geologic mapping,
aeromagnetic data interpretation helps locate normal faults with significant offset under cover,
while LiDAR imagery can be used to identify the age and sense of motion of faults. This study shows
that combined interpretation of these two kinds of data not only confirmed general aspects of
previous geologic mapping of the Rio Grande rift but also provided significant improvements to it.
Examples are given that show how combined interpretation resolved issues specific to this study
June 17, 2013
GECSC Geologist Frank Urban is featured in the
Environmental Monitor article "USGS weather station
network monitors Arctic Alaska's climate". He explains the challenges of maintaining climate
monitoring equipment situated in an extreme environment that includes high winds, freezing
temperatures, and curious, but destructive animals such as bears and wolverines. An overview of the
USGS climate monitoring program and equipment used are also discussed.
June 13, 2013
Unlocking the Potential of RPAS for Geological
By Mike Hutt. Published in
2013 RPAS Yearbook: RPAS—The Global Perspective, p. 119.
Remotely Piloted Aircraft
Systems (RPAS) were first used by USGS researchers in 2004, where they were employed to acquire data
from the Mount St. Helens volcano. Since then, RPAS have been used for missions in many of the USGS
scientific disciplines. As a research tool, this technology has proven advantages including low
cost, mission flexibility, and increased access to remote or dangerous locations.
June 6, 2013
USGS Unmanned Aircraft Systems (UAS) Project Manager
Mike Hutt and Science Center Cartographer Jeff Sloan are quoted in the Las Vegas Review-Journal
article "Drones to spy on Southern Nevada wildlife, not people". The article gives information
about an upcoming UAS project to count mule deer and bighorn sheep in the Nevada Desert National
Wildlife Refuge. Mike and Jeff discuss system capabilities, past missions, as well as how the
Project's policies address the concerns of those who fear that the technology may infringe on an
June 5, 2013
Linking geological and health sciences to assess
childhood lead poisoning from artisanal gold mining in Nigeria
By Geoffrey Plumlee, James
Durant, Suzette Morman, Antonio Neri, Ruth Wolf, Carrie Dooyema, Philip Hageman, Heather Lowers,
Gregory Fernette, Gregory Meeker, William Benzel, Rhonda Driscoll, Cyrus Berry, James Crock, Harland
Goldstein (GECSC), Monique Adams, Casey Bartrem, Simba Tirima, Behrooz Behbod, Ian von Lindern, and
Mary Jean Brown. Published in Environmental Health Perspectives.
In 2010, health officials in
Nigeria linked a lead poisoning outbreak, which resulted in approximately 400 fatalities of children
and affected the health of thousands more, to artisanal gold processing in the region. An
interdisciplinary geological- and health-science assessment was conducted in order to clarify lead
sources and exposure pathways, identify additional toxicants of concern and populations at risk, and
set the framework to examine the potential for similar lead poisoning globally. The findings,
presented in this article, confirm that ore deposit geology and ore processing were fundamental
causes of the extreme contamination of the local soil, plants, and water.
May 24, 2013
In the Denver Post article Keeping up with drones, USGS UAS Project Manager Mike Hutt explains some
of the advantages of using unmanned aerial systems (UAS) in scientific research. The article then
goes on to tell how those advantages, relatively low cost and easy access to wildlife, are—or
could potentially be—employed by hunters. The legal and ethical ramifications of using UAS
technology in outdoor sports are discussed.
May 20, 2013
A Framework for Quantitative Assessment of
Impacts Related to Energy and Mineral Resource Development
By Seth Haines, Jay
Diffendorfer (GECSC), Laurie Balistrieri, Byron Berger, Troy Cook, Don DeAngelis, Holly Doremus,
Donald Gautier, Tanya Gallegos, Margot Gerritsen, Elisabeth Graffy, Sarah Hawkins, Kathleen Johnson,
Jordan Macknick, Peter McMahon, Tim Modde, Brenda Pierce, John Schuenemeyer, Darius Semmens (GECSC),
Benjamin Simon, Jason Taylor, and Katie Walton-Day. Published in Natural Resources Research.
Natural resource planning requires standardized methods for assessing the impacts of resource
development and use. The framework presented in this paper provides such a method—an algorithm
that returns a consistent, reproducible, and quantitative assessment of resource development
impacts. The paper includes examples of how the algorithm could be utilized by combining data from
resource assessments with biological information and geospatial data to model the effects of
development on wildlife habitat.
May 13, 2013
Geological Society of America Special Paper 494, "New Perspectives on Rio Grande Rift Basins:
From Tectonics to Groundwater" summarizes recent research on the Rio Grande rift of the southern
Rocky Mountains. The aim of this publication is to provide better understanding of natural resources
(e.g., ground water), geologic processes (e.g., natural hazards), and geologic history of this large
region. Contributing to this 500-page report are many USGS scientists including GECSC members Mark
Hudson (author and coeditor), Ren Thompson, Cal Ruleman, Ralph Shroba, Florian Maldonado, David
Sawyer, and Scott Minor.
May 7, 2013
GECSC Cartographer Jeff Sloan was interviewed for The
New York Times story "A Drone's-Eye View of Nature". In the article Jeff explains some of the
challenges facing those who wish to use unmanned aerial systems (UAS) for research. In the
accompanying video "Ancient and Modern Birds" Jeff talks about the use of UAS in Sand Hill Crane studies being
conducted in Colorado's Monte Vista National Wildlife Refuge. The video also shows Science Center
member Mark Bauer operating the Raven aircraft used in that project.
May 3, 2013
The geologic records of dust in the
By Dan Muhs. Published in Aeolian Research, volume 9.
geologic records of dust composition, sources, and deposition rates is important for understanding
the role of dust in the overall planetary radiation balance, fertilization of organisms in the
world's oceans, nutrient additions to the terrestrial biosphere and soils, and for paleoclimatic
reconstructions. This review summarizes some of what is known about that record, which is found in a
wide variety of archives, including loess, lake sediments, soils, marine sediments, and glacial ice.
May 3, 2013
Mineralogy and Bioaccessibility of Dust Generated From Soils as Determined by Reflectance
Spectroscopy and Magnetic and Chemical Properties—Nellis Dunes Recreational Area,
By Harland Goldstein (GECSC), Rich Reynolds (GECSC), Suzette Morman, Bruce
Moskowitz, Raymond Kokaly, Dirk Goossens, Brenda Buck, Cody Flagg, Jessica Till, Kimberly Yauk, and
Thelma Berquó. USGS Scientific Investigations Report 2013-5054.
Dust issues related to
climatic variability, atmospheric dynamics, melting of snow and ice, and air quality (including
public health) are at the forefront of scientific investigations as dust storms in the U.S. are
increasing in number and intensity due in part to prolonged drought conditions. To address these
issues, the authors of the report are developing a unique combination of methods that describe
characteristics of atmospheric dust: chemical and mineral compositions, radiative properties, and
elemental bioaccessibility in the human lung and gastric system. Applying these techniques to rare
dust samples from an area near Las Vegas, Nevada, they found relatively high iron concentrations in
the samples, mostly as likely nano-size ferric oxide, that also contained potentially toxic metals
having very high bioaccessibility.
April 30, 2013
Temperature, Wind Speed, and Wind Direction in the National Petroleum Reserve—Alaska and the
Arctic National Wildlife Refuge, 1998-2011
By Frank Urban and Gary Clow. Published as
USGS Open-File Report 2013-1063.
This report provides over ten years of air temperature, wind
speed, and wind direction data collected by the Department of the Interior's climate monitoring
array, part of the Global Terrestrial Network for Permafrost. In addition to presenting data, this
report also describes monitoring, data collection, and quality control methodology. Data collection
by the monitoring array is ongoing and includes several additional climate variables to be released
in subsequent reports.
April 23, 2013
USGS Climate Connections [click link for
YouTube video] visited Denver and gave people on the street an opportunity to ask climate
change-related questions, which were answered by USGS scientists. Among those providing answers are
Darius Semmens, GECSC Research Physical Scientist, and Jenny Briggs, GECSC Research Ecologist. These
interchanges are part of the USGS's effective outreach efforts to involve citizens in the issues of
April 16, 2013
Geological Survey Water Science Strategy—Observing, Understanding, Predicting, and Delivering
Water Science to the Nation
By Eric Evenson, Randall Orndorff, Chuck Blome (GECSC), John
Karl Böhlke, Paul Hershberger, Victoria Langenheim, Gregory McCabe, Scott Morlock, Howard
Reeves, James Verdin, Holly Weyers, and Tamara Wood. USGS Circular 1383-G
This report, which
expands upon the Water Science Strategy outlined in USGS Circular 1309, looks at the relevant issues
facing society and develops a strategy built around observing, understanding, predicting, and
delivering water science for the next 5 to 10 years. The plan also looks at methodologies to build
new capabilities, tools, and delivery systems to meet the Nation's water-resource needs. Nine
priority actions are presented in the report, which combine and elevate the numerous specific
strategic actions listed within its pages.
April 4, 2013
Geological Survey science for the Wyoming Landscape Conservation Initiative—2011 annual
USGS Open-File Report 2013-1033. Authors on the report include Jay Diffendorfer,
Steve Garman, and Sarah Shafer of the GECSC.
This is the fourth annual report produced by the
USGS for the Wyoming Landscape Conservation Initiative, a science-based program founded to assess,
monitor, and enhance aquatic and terrestrial habitats at a landscape scale in the state. The report
details annual work activities conducted in Fiscal Year 2011 and covers ongoing/expanded, completed,
or new projects conducted under the multi-disciplinary science and technical-assistance
April 1, 2013
Origin of the Sinai-Negev erg, Egypt and
Israel: mineralogical and geochemical evidence for the importance of the Nile and sea level
By Dan Muhs (GECSC), Joel Roskin, Haim Tsoar, Gary Skipp (GECSC), James Budahn,
Amihai Sneh, Naomi Porat, Jean-Daniel Stanley, Itzhak Katra, and Dan Blumberg. Published in
Quaternary Science Reviews, vol. 69.
It has been proposed that the Nile Delta is the source
of the sand in the Sinai-Negev erg, but that assertion has never been proven with empirical data.
Using mineralogical and geochemical data, this study confirmed that it was the primary source of
sediments of this region. By examining cores, this study also shows how sea level during the the
Last Glacial period, along with favorable climatic conditions, was a major contributing factor of
March 12, 2013
GECSC Supervisory Cartographer Mike Hutt is quoted in
the Reuters article PDAC-Drone
startups woo stretched miners for survey work. The story reports on how the mining industry is
benefitting from unmanned aircraft system (UAS) technology and includes examples of the GECSC UAS
Project's work with that field.
March 7, 2013
Aeolian controls on soil geochemistry and
weathering fluxes in high-elevation ecosystems of the Rocky Mountains, USA
Lawrence, Rich Reynolds (GECSC), Michael Ketterer, and Jason Neff. Published in Geochimica et
Cosmochimica Acta, volume 107.
Long-term, persistent inputs of atmospheric dust commonly
accumulate in soils and must then help sustain chemical weathering fluxes from these soils. The
authors determined the contribution of far-traveled atmospheric dust to soil chemistry for various
montane soil types in Colorado on the basis of geochemical mass-balance and calculated chemical
weathering rates from these soils. Weathering of dust explained as much as 70% of the long-term
weathering flux. These results are significant because the chemical weathering of silicate minerals
is an important regulator of the climate system through interactions with the carbon cycle.
March 4, 2013
States-Mexican Borderlands—Facing tomorrow's challenges through USGS science
by Randy Updike, Gene Ellis (GECSC), Ric Page (GECSC), Melanie Parker, Jay Hestbeck, and William
Horak. USGS Circular 1380.
As the principal science bureau of the U.S. Department of the
Interior, the USGS has a unique role to play in the resolution of a multitude of natural and
sociological issues in the Borderlands, the area in both countries along the United States-Mexican
border. The USGS applies geographical, geospatial, biological, hydrological, and geological sciences
to these complex issues, and the results of that scientific research provide insight into the area's
natural systems and their relation to human activity.
February 25, 2013
The Ice Dynamics, Paleoclimate, and Ice Cores
Project seeks to provide understanding of the physical characteristics of ice sheets as well as
contribute data that national and international multi-disciplinary teams use in their
high-resolution global climate history records. The project's new website provides background,
objectives, and key findings of the project along with publications that have resulted from research
conducted by project staff. An overview of the project-related facilities at the U.S. National Ice
Core Laboratory is also presented.
February 21, 2013
Mapping, monitoring, and modeling Western Gateway
Community landscape dynamics
By David Hester. USGS Fact Sheet 2012-3141.
public lands in the western United States are becoming increasingly surrounded by Gateway
Communities. These communities are undergoing landscape change due to population growth, economic
growth, and the resulting land-use development. Socioeconomic, demographic, and land-use changes in
Gateway Communities are often perceived as threats to Federal land resources, natural amenities,
cultural resources, and recreational opportunities. However, land-surface disturbances on Federal
public lands, such as conventional and alternative energy development (which impact surrounding
Gateway Communities), are also environmental and societal issues that Federal land and adjacent
regional community planners need to consider in their long-range land-use planning.
February 14, 2013
Biogeochemistry of Beetle Killed Forests:
Explaining a Weak Nitrate Response
By Charles Rhoades, James McCutchan, Jr., Leigh
Cooper, David Clow, Thomas Detmer, Jenny Briggs (GECSC), John Stednick, Thomas Veblen, Rachel Ertz,
Gene Likens, and William Lewis, Jr. Published in the Proceedings of the National Academy of
Sciences, v. 110, no. 5.
In United States and European watersheds, where atmospheric
deposition of inorganic nitrogen is moderate to low, disturbance of forests by timber harvest or
violent storms causes a dramatic increase in stream nitrate concentration. In contrast, no
significant increase in streamwater nitrate concentrations has occurred following extensive tree
mortality caused by the mountain pine beetle in Colorado. This paper synthesizes data from several
field studies at multiple scales and develops a model to account for the unexpected dynamics of
lodgepole pine forests' response to epidemic levels of infestation. Results suggest that the
combination of low atmospheric nitrogen deposition, tree mortality spread over multiple years, and
high compensatory capacity associated with undisturbed residual vegetation, regeneration, and soils
explains the ability of these beetle-infested watersheds to retain nitrate despite widespread
mortality of the dominant canopy tree species.
February 7, 2013
Towards a publicly available, map-based regional
software tool to estimate unregulated daily streamflow at ungauged rivers
Archfield, Peter Steeves, John Guthrie (GECSC), and Kernell Ries. Published in Geoscientific Model
Development, vol. 6.
This paper presents one of the first publicly available, map-based
software tools to provide unregulated daily streamflow time series for any user-selected river
location in a particular study region. The software tool, which
requires only an internet connection, a web browser, and a macro-based spreadsheet program, was
developed for the Connecticut River basin, but the overall framework is adaptable to other
January 31, 2013
Challenges and opportunities for ecosystem services
science and policy in arid and semiarid environments
By Ken Bagstad (GECSC), Darius Semmens
(GECSC), and Charles van Riper III. Published as Chapter 4 of Colorado Plateau V: Research, environmental
planning, and management for effective conservation, University of Arizona Press.
book chapter describes the scientific challenges and policy opportunities for using ecosystem
services as a management framework for the Colorado Plateau. The temporal and spatial distribution
of water and the location of beneficiaries are key drivers of supply and demand for ecosystem
services in this semiarid, lightly populated region. This chapter is part of a larger work
synthesizing the potential contributions of recent scientific advances toward conservation and
resource management on the Colorado Plateau.
January 30, 2013
The Cambrian-Ordovician rocks of Sonora, Mexico,
and southern Arizona, southwestern margin of North America (Laurentia)
By Ric Page (GECSC),
Anita Harris, and John Repetski. Published as Chapter 35 of The great American carbonate bank: The
geology and economic resources of the Cambrian-Ordovician Sauk megasequence of Laurentia. (American
Association of Petroleum Geologists Memoir 98)
This book chapter summarizes the stratigraphy,
paleontology, and economic resources of Cambrian and Ordovician rocks in Sonora, Mexico and southern
Arizona using selected stratigraphic reference sections. It is part of a larger publication that
describes the deposits of the Great American Carbonate Bank, of North America, that comprise
carbonate and clastic rocks deposited during Cambrian through earliest Middle Ordovician
January 18, 2013
Can We Span the Boundaries Between Wildland Fire Science and Management in the United
By Susan Kocher, Eric Toman, Sarah Trainor, Vita Wright, Jenny Briggs (GECSC),
Charles Goebel, Eugénie MontBlanc, Annie Oxarart, Donna Pepin, Toddi Steelman, Andrea Thode,
and Thomas Waldrop. Published in Journal of Forestry, v. 110.
In 2009, the federal Joint Fire
Science Program initiated a national network of regional fire science consortia to promote wildland
fire science and its application to resource management priorities specific to diverse regional
ecosystems. Needs assessments were conducted by the consortia in each region, then synthesized by
this team of authors at the national level. Results showed striking similarities among the regions
in how fire science is accessed and used, barriers to its use, and research information needed;
however, some notable regional differences were revealed. The article discusses opportunities and
obstacles for fire science application and documents the advantages of regionally focused
boundary-spanning organizations. Jenny Briggs, Research Ecologist, serves as the USGS representative
on the interagency, multi-institution Steering Team of the Southern Rockies Fire Science Network
January 18, 2013
Mike Hutt of the Unmanned Aircraft Systems Project
(UAS) is quoted in the article "Drones for
Hire" that appears in the January issue of Smithsonian's Air and Space magazine. The article
describes the logistics of a UAS Project mission, the hardware used, and the operation of the
aircraft. Mike discusses the capabilities and potential uses of unmanned aircraft systems within the
USGS and elsewhere.
January 18, 2013
Mike Hutt and Jeff Sloan were interviewed by
Patrick Egan and Gene Robinson on the January 16 sUAS News
Podcast. Mike and Jeff answered questions about the program's background, the evolving
technology of unmanned aircraft systems (UAS), and upcoming project missions. The public benefit of
the UAS Project missions are also discussed.
January 15, 2013
January's issue of Unmanned Systems magazine
features the cover story "Saving
Money, Aiding Wildlife: Lower Cost Means More Surveys with UAS for USGS" [PDF] by Gaea
Honeycutt. Along with a history of the USGS UAS program and
description of the office's capabilities and projects, the story includes a Q&A with GECSC
Supervisory Cartographer Mike Hutt. Among the topics discussed is the cost benefits of using UAS
craft over other forms of aerial monitoring.
January 14, 2013
Spatial Analysis of Cultural Ecosystem Service Valuation by Regional Stakeholders in Florida—A
Coastal Application of the Social Values for Ecosystem Services (SolVES) Tool
Coffin (GECSC), Robert Swett, and Zachary Cole. USGS Fact Sheet 2012-3125.
Geographer Alisa Coffin is working with the Florida Sea Grant College Program to map nonmonetary
values of cultural ecosystem services for a pilot area on Florida's Gulf Coast. Using this
information, the USGS SolVES 2.0 tool, a GIS application,
will provide quantitative models to relate perceived nonmonetary values assigned to locations by
survey respondents with the underlying environmental characteristics of those same locations. A
critical goal is to integrate research results with coastal and marine spatial planning
applications, thus making them relevant to coastal planners and managers in their daily efforts to
sustainably manage coastal resources.
December 31, 2012
Ecosystem Service Flows under Uncertainty with Stochastic SPAN [PDF]
By Gary Johnson,
Robert Snapp, Ferdinando Villa, and Ken Bagstad (GECSC). Presented at the International
Environmental Modelling and Software Society's 2012 International Congress on Environmental
Modelling and Software Managing Resources of a Limited Planet in Leipzig, Germany.
introduces a systematic approach to address both the unreliability of data that ecosystem services
modelers have access to and the difficulty in communicating that uncertainty through a stochastic
adaptation of the Service Path Attribution Networks (SPAN) framework. This framework accounts for
the spatial dynamics of ecosystem service flows and uncertainty associated with those flows. The
SPAN algorithms are presented here as a framework which combines probabilistic input data with a
stochastic transport model in order to generate probabilistic spatial outputs.
December 21, 2012
Quaternary Geologic Map of the Glasgow 1° x 2°
By Dave Fullerton (GECSC), Roger Colton, and Chuck Bush (GECSC). USGS
Open-File Report 2012-1217.
This map of the Glasgow quadrangle was prepared to serve as a
database for compilation of a Quaternary geologic map of parts of North Dakota and Montana and
adjacent Canada. It encompasses approximately 16,084 km2 (6,210 mi2). The map
units are surficial deposits and materials, not landforms.
December 20, 2012
Hydrology and Geochemistry of Yucca Mountain and Vicinity, Southern Nevada and California
Geological Society of America Memoir 209. Edited by John Stuckless.
This book, along with
its companion volume The Geology and Climatology of
Yucca Mountain and Vicinity, Southern Nevada and California, presents a comprehensive approach
to characterizing a potential site for the disposal of radioactive waste. Much of this work
represents innovative approaches addressing the geochemistry and hydrology of the site, as well as
the paleohydrology and transport of radionuclides under ambient and thermally altered conditions.
Although the studies focused on Yucca Mountain, the methods and interpretations should be useful to
any similar effort.
December 17, 2012
Todd Hawbaker was interviewed for the Stateline article "Wildfire Epidemic Leaves States Searching for Answers". He
was asked about his work projecting changes in wildfire occurrence and greenhouse gas emissions
under climate change that was recently published in Baseline
and Projected Future Carbon Storage and Greenhouse-Gas Fluxes in Ecosystems of the Western United
States (USGS Professional Paper 1797).
2012Ecosystem services valuation to support
decision making on public lands—A case study of the San Pedro River watershed, Arizona
By Ken Bagstad (GECSC), Darius Semmens (GECSC), Rob Winthrop, Delilah Jaworksi, and Joel Larson.
USGS Scientific Investigations Report 2012-5251.
This report details the findings of the
Bureau of Land Management-USGS Ecosystem Services Valuation Pilot Study. The study evaluated
alternative methods and tools that quantify and value ecosystem services as well as assessed the
tools' readiness for use in decisionmaking processes. The report includes suggestions of scientific
needs that agencies such as the USGS could help meet to improve these decisionmaking tools.
December 4, 2012Quaternary Geologic Map of the Vicksburg 4° x
6° Quadrangle, United States
Digital edition by Chuck Bush of USGS Miscellaneous
Investigations Series I-1420 (NI-15).
The geologic data of this map, first published as a
printed edition in 1990 as part of the Quaternary Geologic Atlas of the United States, has been
captured digitally for use with GIS applications. These data are presented here along with images of
the printed map sheet, map text, and ArcInfo coverage export files and ArcView shape files.
December 3, 2012Lower-Crustal Xenoliths from Jurassic
Kimberlite Diatremes, Upper Michigan (USA): Evidence for Proterozoic Orogenesis and Plume Magmatism
in the Lower Crust of the Southern Superior Province
By Robert Zartman, Pamela Kempton,
Jim Paces (GECSC), Hilary Downes, Ian Williams, Gábor Dobosi, and Kiyota Futa. Published in the
Journal of Petrology.
This study of mafic granulite xenoliths contained within two diatremes
from the Jurassic Michigan kimberlite province shows that the lower crust beneath northern Michigan
formed in Archean times and underwent a variety of tectono-magmatic processes throughout the
Proterozoic, including orogenesis, partial melting and mafic magmatic underplating in response to
upwelling mantle plumes.
November 29, 2012
Quaternary Geologic Map of the White Lake 4° x
6° Quadrangle, United States
Digital edition by Chuck Bush of USGS Miscellaneous
Investigations Series I-1420 (NH-15).
The geologic data of this map, first published as a
printed edition in 1990 as part of the Quaternary Geologic Atlas of the United States, has been
captured digitally for use with GIS applications. This data is presented here along with images of
the printed map sheet, map text, and ArcInfo coverage export files and ArcView shape files.
November 28, 2012
Tectonic influences on the preservation of
marine terraces: Old and new evidence from Santa Catalina Island, California
Schumann (GECSC), Scott Minor (GECSC), Dan Muhs (GECSC), Lindsey Groves, and Jack McGeehin.
Published in Geomorphology, v. 179.
Among the California Channel Islands, only Santa Catalina
Island lacks clearly identifiable marine terrace deposits or landforms. River long profile data
suggests that rapid uplift, caused by a restraining bend in the Catalina Fault, caused intense
landscape rejuvenation that likely removed all traces of subaerial marine terraces by erosion.
Bathymetric data indicate that submerged marine terraces around Santa Catalina Island are similar to
those surrounding the other Channel Islands, which suggests that the same terrace-forming processes
acted on Catalina Island as on the other Channel Islands.
November 15, 2012
3-D geologic framework modeling and its application to groundwater flow studies
Blome (GECSC) and David V. Smith, USGS Fact Sheet 2012-3106.
Discussed in this publication
are the evolution of project three-dimensional subsurface framework modeling, research in
hydrostratigraphy and airborne geophysics, and methodologies used to link geologic and groundwater
flow models. Three-dimensional framework models of the Edwards and Arbuckle-Simpson aquifers are
shown as examples.
November 15, 2012
On November 6,
GECSC emeritus Ken Pierce was awarded the Distinguished Career Award at the annual Quaternary
Geology and Geomorphology Section meeting of the Geological Society of America in Charlotte, North
Carolina. This award recognizes an outstanding geologist who has demonstrated excellence in their
contributions to science through research of the Quaternary Period.
November 15, 2012
half-million-year record of paleoclimate from the Lake Manix Core, Mojave Desert, California
By Marith Reheis (GECSC), Jordan Bright, Steve Lund, David Miller, Gary Skipp (GECSC), and Robert
Fleck. Published in Palaeogeography, Palaeoclimatology, Palaeoecology, v. 365-366.
Study of a
45-m-long core of lacustrine sediment from Lake Manix, the former terminus of the Mojave River,
along with supplemental outcrop data, revealed a robust record of Mojave River discharge over the
last half-million years. Significant findings from this study include: persistence of Lake Manix
nearly continuously from oxygen-isotope stage (OIS) 10 through stage 3, including during
interglacial periods; a surprising summer-dominated hydrology for the area during OIS 12 as opposed
to winter dominance in later periods; and a highly variable stable isotope record buffered by
evaporation during both interglacial and glacial periods.
October 26, 2012
GECSC Scientist Emeritus Florian Maldonado authored the
chapter "Summary of the geology of the northern part of the Sierra Cuchillo, Socorro and Sierra
Counties, southwestern New Mexico" for the New Mexico Geological Society Guidebook,
63rd Field Conference, Warm Springs Region.
October 24, 2012
Map of Mesa Verde National Park, Montezuma County, Colorado
By Paul Carrara, in
cooperation with the National Park Service. USGS Scientific Investigations Map 3224.
Verde National Park in southwestern Colorado was established to preserve and protect the artifacts
and dwelling sites, including the famous cliff dwellings, of the Ancestral Puebloan people. The map,
which encompasses an area of about 100 mi2 (260 km2), includes all of Mesa
Verde National Park, and a small part of the Ute Mountain Indian Reservation. Surficial deposits
depicted on the map include: artificial fills, alluvium of small ephemeral streams, alluvium
deposited by the Mancos River, residual gravel on high mesas, a combination of alluvial and
colluvial deposits, fan deposits, colluvial deposits, loess, and various forms of mass movement.
Bedrock units include the Cliff House Sandstone, Menefee Formation, Point Lookout Sandstone, and
Mancos Shale all of Late Cretaceous age. In addition, minette dikes, of Oligocene age, found at
several locations in the park are shown on the map. The surficial geology of the park is depicted on
the map and described in detail in the accompanying pamphlet.
October 12, 2012
In their story A Drone's Eye
View of the Elwha River, Oregon Public Broadcasting has reported on efforts to monitor the impacts of the
Elwah Dam removal using unmanned aircraft systems (UAS). The GECSC's National UAS Project
Office, partnering with the National Park Service and Bureau of Reclamation, collected data that
will help researchers better understand how the dam's removal affected wildlife, the surrounding
environment, and geology of the area. The imagery collected will also be useful in the study of how
the emptied reservoir recovers over time.
Each year the USGS Office of Communication and Outreach honors outstanding publications
with the Eugene M. Shoemaker Communication Award. This year, the award for Graphic Product went to
the Geologic Map of Big Bend National Park, Texas by
GECSC members Kenzie Turner, Ric Page, and Margaret Berry, with editing and digital cartography by
Gayle Dumonceaux and layout by Carol Quesenberry, both of the Denver Publishing Service Center.
September 27, 2012
Soil genesis on the island of Bermuda in the
Quaternary: The importance of African dust transport and deposition
By Dan Muhs (GECSC),
Jim Budahn, Joseph Prospero, Gary Skipp (GECSC), and Stanley Herwitz. Published in Journal of
Geophysical Research, vol. 117.
The origin of terra rossa, red or reddish-brown, clay-rich
soils overlying high-purity carbonate substrates, has intrigued geologists and pedologists for
decades. This study of terra rossa on Bermuda found that soils on this island in the western
Atlantic margin have been influenced by long-range-transported dust inputs from Africa over much of
the past ∼500,000 years.
September 12, 2012
Senior Scientist Rich Reynolds was interviewed on
KPCW, public radio in Park City, Utah, about dust issues in the American West.
August 31, 2012
Quantitative estimation of climatic
parameters from vegetation data in North America by the mutual climatic range technique
By Bob Thompson (GECSC), Kat Anderson, Richard Pelltier (GECSC), Laura Strickland (GECSC),
Patrick Bartlein, and Sarah Shafer (GECSC). Published in Quaternary Science Reviews, v. 51, p.
This paper presents a new approach for paleoclimatic reconstructions from
paleobiological data. By incorporating modern relations between climatic parameters and plant
distributions, the commonly used mutual climatic range technique will yield more precise
August 24, 2012
Sea-level history of past interglacial periods
from uranium-series dating of corals, Curaçao, Leeward Antilles islands
By Dan Muhs
(GECSC), John Pandolfi, Kathleen Simmons (GECSC), and Randy Schumann (GECSC). Published in
By uranium-series dating of fossil corals, the ages of past high sea
levels on Curaçao island were obtained. This information helps us better understand the
magnitude of possible future sea-level rise as caused by melting of large ice sheets in Greenland
August 23, 2012
Holocene alluvial stratigraphy and response to
climate change in the Roaring River valley, Front Range, Colorado, USA
By Rich Madole.
Published in Quaternary Research.
The stratigraphic analyses presented here contradict the
opinion, as argued in the water-rights trial USA v. Colorado, that stream channels in the higher
parts of the Front Range are relics of the Pleistocene and nonalluvial under the present climate.
The findings of this study give a better understanding of the hydroclimatic variability during the
recent geologic past, which is useful in not only reconstructing the climatic history of the
drainage basin, but for the current management of water resources.
August 3, 2012
GECSC Research Geologist Scott Minor was interviewed and is
quoted in the story "
Underground fire continues to burn north of Fillmore" that appeared in the July 17 edition of
the Ventura County Star. The article is about a thermal anomaly that has caused an underground fire
in Ventura County, California.
July 18, 2012
Quaternary geologic map of the Louisville 4° x
6° quadrangle, United States
Digital edition by Chuck Bush of USGS Miscellaneous
Investigations Series Map I-1420 (NJ-16).
The geologic data of this map, first published as a
printed edition in 1991 as part of the Quaternary Geologic Atlas of the United States, has been
captured digitally for use with GIS applications. This data is presented here along with images of
the printed map sheet, map text, and ArcInfo coverage export files and ArcView shape files.
July 17, 2012
Fingerprinting of glacial silt in lake
sediments yields continuous records of alpine glaciation (35-15 ka), western USA
Rosenbaum (GECSC), Rich Reynolds (GECSC), and Steven Colman. Published in Quaternary Research.
Magnetic properties were used to derive records of glacial silt in sediments from Upper Klamath
Lake (OR) and Bear Lake (UT and ID). These records provide continuous radiocarbon-dated records of
the last glacial interval for the southeastern Cascade Range and northwestern Uinta Mountains,
respectively. As sea level began to fall prior to the last glacial maximum (LGM), existing glaciers
in the Upper Klamath Lake area expanded. At the beginning of the global LGM (∼26.5 ka),
glaciers appeared in the Bear Lake area, and Upper Klamath Lake-area glaciers underwent further
expansion. Both records indicate that glaciers reached maximum extents near the end of the global
LGM, remained near their maxima for ∼1000 years, and underwent two stages of retreat separated
by a short period of expansion.