Magnetostratigraphy of the Neogene Chaka basin and its implications for mountain building processes in the north-eastern Tibetan Plateau
H.-P. Zhang, W.H. Craddock, Richard O. Lease, W.-T. Wang, D.-Y. Yuan, P.-Z. Zhang, P. Molnar, D.-W. Zheng, W.-J. Zheng
2012, Basin Research (24) 31-50
Magnetostratigraphy of sedimentary rock deposited in the Chaka basin (north‐eastern Tibetan Plateau) indicates a late Miocene onset of basin formation and subsequent development of the adjacent Qinghai Nan Shan. Sedimentation in the basin initiated at ∼11 Ma. In the lower part of the basin fill, a coarsening‐upward sequence starting at ∼9 Ma,...
Relating stick-slip friction experiments to earthquake source parameters
Arthur F. McGarr
2012, Geophysical Research Letters (39)
Analytical results for parameters, such as static stress drop, for stick-slip friction experiments, with arbitrary input parameters, can be determined by solving an energy-balance equation. These results can then be related to a given earthquake based on its seismic moment and the maximum slip within its rupture zone, assuming that...
The impact of biotic/abiotic interfaces in mineral nutrient cycling: A study of soils of the Santa Cruz chronosequence, California
A. F. White, M. S. Schulz, D.V. Vivit, T.D. Bullen, J. Fitzpatrick
2012, Geochimica et Cosmochimica Acta (77) 62-85
Biotic/abiotic interactions between soil mineral nutrients and annual grassland vegetation are characterized for five soils in a marine terrace chronosequence near Santa Cruz, California. A Mediterranean climate, with wet winters and dry summers, controls the annual cycle of plant growth and litter decomposition, resulting in net above-ground productivities of...
Scientific basis for safely shutting in the Macondo Well after the April 20, 2010 Deepwater Horizon blowout
Stephen H. Hickman, Paul A. Hsieh, Walter D. Mooney, Catherine B. Enomoto, Philip H. Nelson, Larry Mayer, Peter Flemings, Kathryn Moran, Thomas S. Weber, Marcia K. McNutt
James R. Rice, editor(s)
2012, PNAS (109) 20268-20273
As part of the government response to the Deepwater Horizon blowout, a Well Integrity Team evaluated the geologic hazards of shutting in the Macondo Well at the seafloor and determined the conditions under which it could safely be undertaken. Of particular concern was the possibility that, under the anticipated high...
Impact of wildfire and slope aspect on soil temperature in a mountainous environment
Brian A. Ebel
2012, Vadose Zone Journal (11)
Soil temperature changes after landscape disturbance impact hydrology, ecology, and geomorphology. This study used field measurements to examine wildfire and aspect effects on soil temperatures. Combustion of the litter and duff layers on north-facing slopes removed pre-fire aspect-driven soil temperature controls.Wildfire is one of the most significant disturbances in mountainous...
Significance of a 3D Elevation Program to wetland mapping
Gregory I. Snyder, Megan Lang
2012, National Wetlands Newsletter (34) 11-15
The recent National Enhanced Assessment conducted by the U.S. Geology Survey identified billions of dollars in potential annual benefits if a national-scale enhanced elevation data program was implemented. Given the importance of topography to wetlands, wetland mapping could benefit significantly from improved elevation data. ...
The paleohydrology of unsaturated and saturated zones at Yucca Mountain, Nevada, and vicinity
James B. Paces, Joseph F. Whelan
John S. Stuckless, editor(s)
2012, Book chapter, Hydrology and geochemistry of Yucca Mountain and vicinity, Southern Nevada and California
Surface, unsaturated-zone, and saturated-zone hydrologic conditions at Yucca Mountain responded to past climate variations and are at least partly preserved by sediment, fossil, and mineral records. Characterizing past hydrologic conditions in surface and subsurface environments helps to constrain hydrologic responses expected under future climate conditions and improve predictions of repository...
Wetlands of the Central Valley of California and Klamath Basin
Joseph P. Fleskes
Darold P. Batzer, Andrew H. Baldwin, editor(s)
2012, Book chapter, Wetland habitats of North America: ecology and conservation concerns
No abstract available. ...
Gulf Coast Ecosystem Restoration Task Force---Gulf of Mexico Ecosystem Science Assessment and Needs
Shelby Walker, Alyssa M. Dausman, Dawn L. Lavoie, editor(s)
2012, Report
The Gulf Coast Ecosystem Restoration Task Force (GCERTF) was established by Executive Order 13554 as a result of recommendations from “America’s Gulf Coast: A Long-term Recovery Plan after the Deepwater Horizon Oil Spill” by Secretary of the Navy Ray Mabus (Mabus Report). The GCERTF consists of members from 11 Federal...
A robust method to forecast volcanic ash clouds
Roger P. Denlinger, Michael J. Pavolonis, Justin Sieglaff
2012, Journal of Geophysical Research D: Atmospheres (117) 1-10
Ash clouds emanating from volcanic eruption columns often form trails of ash extending thousands of kilometers through the Earth's atmosphere, disrupting air traffic and posing a significant hazard to air travel. To mitigate such hazards, the community charged with reducing flight risk must accurately assess risk of ash ingestion for...
A plant distribution shift: temperature, drought or past disturbance?
Dylan W. Schwilk, Jon E. Keeley
2012, PLoS ONE (7)
Simple models of plant response to warming climates predict vegetation moving to cooler and/or wetter locations: in mountainous regions shifting upslope. However, species-specific responses to climate change are likely to be much more complex. We re-examined a recently reported vegetation shift in the Santa Rosa Mountains, California, to better understand...
Verifiable metamodels for nitrate losses to drains and groundwater in the Corn Belt, USA
Bernard T. Nolan, Robert W. Malone, Jo Ann M. Gronberg, K.R. Thorp, Liwang Ma
2012, Environmental Science & Technology (46) 901-908
Nitrate leaching in the unsaturated zone poses a risk to groundwater, whereas nitrate in tile drainage is conveyed directly to streams. We developed metamodels (MMs) consisting of artificial neural networks to simplify and upscale mechanistic fate and transport models for prediction of nitrate losses by drains and leaching in the...
Airborne electromagnetic imaging of discontinuous permafrost
B. J. Minsley, J.D. Abraham, B. D. Smith, J. C. Cannia, C.I. Voss, M.T. Jorgenson, Michelle Ann Walvoord, B.K. Wylie, L. Anderson, L.B. Ball, M. Deszcz-Pan, T.P. Wellman, T. A. Ager
2012, Geophysical Research Letters (39) 1-8
The evolution of permafrost in cold regions is inextricably connected to hydrogeologic processes, climate, and ecosystems. Permafrost thawing has been linked to changes in wetland and lake areas, alteration of the groundwater contribution to streamflow, carbon release, and increased fire frequency. But detailed knowledge about the dynamic state of permafrost...
The unexpected discovery of blind snakes (Serpentes: Typhlopidae) in Micronesia: Two new species of Ramphotyphlops from the Caroline Islands
A.H. Wynn, R.P. Reynolds, D.W. Buden, M. Falanruw, B. Lynch
2012, Zootaxa 39-54
Two new blind snakes in the genus Ramphotyphlops are described from Ulithi (R. hatmaliyeb sp. nov.) and Ant Atoll (R. adocetus sp. nov.) in the Caroline Islands, the first blind snake species known from Micronesia east of Palau (excluding Ramphotyphlops braminus). Both species are unusual in being known only from...
Thinning of young Douglas-fir forests decreases density of northern flying squirrels in the Oregon Cascades
Tom Manning, Joan C. Hagar, Brenda C. McComb
2012, Forest Ecology and Management (264) 115-124
Large-scale commercial thinning of young forests in the Pacific Northwest is currently promoted on public lands to accelerate the development of late-seral forest structure for the benefit of wildlife species such as northern spotted owls (Strix occidentalis caurina) and their prey, including the northern flying squirrel (Glaucomys sabrinus). Attempts to...
Ecological controls on the shell geochemistry of pink and white Globigerinoides ruber in the northern Gulf of Mexico: implications for paleoceanographic reconstruction
Julie N. Richey, Richard Z. Poore, Benjamin P. Flower, David J. Hollander
2012, Marine Micropaleontology (82-83) 28-37
We evaluate the relationship between foraminiferal test size and shell geochemistry (δ13C, δ18O, and Mg/Ca) for two of the most commonly used planktonic foraminifers for paleoceanographic reconstruction in the subtropical Atlantic Ocean: the pink and white varieties of Globigerinoides ruber. Geochemical analyses were performed on foraminifera from modern core-top samples...
Oxygen and sulfur isotope systematics of sulfate produced during abiotic and bacterial oxidation of sphalerite and elemental sulfur
N. Balci, B. Mayer, W. C. Pat Shanks III, K.W. Mandernack
2012, Geochimica et Cosmochimica Acta (77) 335-351
Studies of metal sulfide oxidation in acid mine drainage (AMD) systems have primarily focused on pyrite oxidation, although acid soluble sulfides (e.g., ZnS) are predominantly responsible for the release of toxic metals. We conducted a series of biological and abiotic laboratory oxidation experiments with pure and Fe-bearing sphalerite (ZnS &...
A Holocene record of endogenic iron and manganese precipitation and vegetation history in a lake-fen complex in northwestern Minnesota
Walter E. Dean, L.A. Doner
2012, Journal of Paleolimnology (47) 29-42
Little Shingobee Lake and Fen are part of the extensive network of lakes and wetlands in the Shingobee River headwaters of northwestern Minnesota, designed to study the interactions between surface and ground waters. Prior to about 11.2 cal. ka, most of these lakes and wetlands were interconnected to form glacial Lake...
Landscape controls on the timing of spring, autumn, and growing season length in mid-Atlantic forests
A.J. Elmore, S.M. Guinn, B. J. Minsley, A.D. Richardson
2012, Global Change Biology (18) 656-674
The timing of spring leaf development, trajectories of summer leaf area, and the timing of autumn senescence have profound impacts to the water, carbon, and energy balance of ecosystems, and are likely influenced by global climate change. Limited field-based and remote-sensing observations have suggested complex spatial patterns related to geographic...
Humic acid facilitates the transport of ARS-labeled hydroxyapatite nanoparticles in iron oxyhydroxide-coated sand
Dengjun Wang, Scott A. Bradford, Ronald W. Harvey, Bin Gao, Long Cang, Dongmei Zhou
2012, Environmental Science & Technology (46) 2738-2745
Hydroxyapatite nanoparticles (nHAP) have been widely used to remediate soil and wastewater contaminated with metals and radionuclides. However, our understanding of nHAP transport and fate is limited in natural environments that exhibit significant variability in solid and solution chemistry. The transport and retention kinetics of Alizarin red S (ARS)-labeled nHAP...
A spatial cluster analysis of tractor overturns in Kentucky from 1960 to 2002
D.M. Saman, H.P. Cole, A. Odoi, M.L. Myers, D.I. Carey, S.C. Westneat
2012, PLoS ONE (7)
Background:Agricultural tractor overturns without rollover protective structures are the leading cause of farm fatalities in the United States. To our knowledge, no studies have incorporated the spatial scan statistic in identifying high-risk areas for tractor overturns. The aim of this study was to determine whether tractor overturns cluster in certain...
Climatic forcing of Quaternary deep-sea benthic communities in the North Pacific Ocean
Moriaki Yasuhara, G. Hunt, T. M. Cronin, N. Hokanishi, H. Kawahata, Akira Tsujimoto, M. Ishitake
2012, Paleobiology (38) 162-179
There is growing evidence that changes in deep-sea benthic ecosystems are modulated by climate changes, but most evidence to date comes from the North Atlantic Ocean. Here we analyze new ostracod and published foraminiferal records for the last 250,000 years on Shatsky Rise in the North Pacific Ocean. Using linear...
Near‐surface void detection using a seismic landstreamer and horizontal velocity and attenuation tomography
Sean F. Buckley, John W. Lane Jr.
2012, Conference Paper, Symposium on the Application of Geophysics to Engineering and Environmental Problems 2012
The detection and characterization of subsurface voids plays an important role in the study of karst formations and clandestine tunnels. Horizontal velocity and attenuation tomography (HVAT) using offset‐fan shooting and a towed seismic land streamer is a simple, rapid, minimally invasive method that shows promise for detecting near‐surface voids and...
Upper Klamath Basin Landsat Image for October 29, 2006: Path 45 Rows 30 and 31
Daniel T. Snyder
2012, Report
This image is a mosaic of Landsat-5 images of the upper Klamath Basin. The original images were obtained from the U.S. Geological Survey Earth Resources Observation and Science Center (EROS). EROS is responsible for archive management and distribution of Landsat data products. The Landsat-5 satellite is part of an ongoing...
Quantifying anthropogenically driven morphologic changes on a barrier island: Fire Island National Seashore, New York
Meredith G. Kratzmann, Cheryl J. Hapke
2012, Journal of Coastal Research (28) 76-88
Beach scraping, beach replenishment, and the presence of moderate development have altered the morphology of the dune–beach system at Fire Island National Seashore, located on a barrier island on the south coast of Long Island, New York. Seventeen communities are interspersed with sections of natural, nonmodified land within the park...
