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Page 563, results 14051 - 14075

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Not all publications have extents, not all extents are completely accurate
Micrometer-scale U–Pb age domains in eucrite zircons, impact re-setting, and the thermal history of the HED parent body
M.D. Hopkins, S.J. Mojzsis, W.F. Bottke, Oleg Abramov
2015, Icarus (245) 367-378
Meteoritic zircons are rare, but some are documented to occur in asteroidal meteorites, including those of the howardite–eucrite–diogenite (HED) achondrite clan (Rubin, A. [1997]. Meteorit. Planet. Sci. 32, 231–247). The HEDs are widely considered to originate from the Asteroid 4 Vesta. Vesta and the other large main belt asteroids record...
2014 National Park visitor spending effects: economic contributions to local communities, states, and the nation
Catherine Cullinane Thomas, Christopher Huber, Lynne Koontz
2015, Natural Resource Report NPS/NRSS/EQD/NRR—2015/947
The National Park System covers more than 84 million acres and is comprised of more than 401 sites across the Nation. These lands managed by the National Park Service (NPS) serve as recreational destinations for visitors from across the Nation and around the world. On vacations or on day trips,...
Correspondence of biological condition models of California streams at statewide and regional scales
Jason T. May, Larry R. Brown, Andrew C. Rehn, Ian R. Waite, Peter R Ode, Raphael D Mazor, Kenneth C Schiff
2015, Environmental Monitoring and Assessment (187)
We used boosted regression trees (BRT) to model stream biological condition as measured by benthic macroinvertebrate taxonomic completeness, the ratio of observed to expected (O/E) taxa. Models were developed with and without exclusion of rare taxa at a site. BRT models are robust, requiring few assumptions compared with traditional modeling...
Kinematics of shallow backthrusts in the Seattle fault zone, Washington State
Thomas L. Pratt, K.G. Troost, Jackson K. Odum, William J. Stephenson
2015, Geosphere (11) 1948-1974
Near-surface thrust fault splays and antithetic backthrusts at the tips of major thrust fault systems can distribute slip across multiple shallow fault strands, complicating earthquake hazard analyses based on studies of surface faulting. The shallow expression of the fault strands forming the Seattle fault zone of Washington State shows the...
High‐resolution trench photomosaics from image‐based modeling: Workflow and error analysis
Nadine G. Reitman, Scott E.K. Bennett, Ryan D. Gold, Richard W. Briggs, Christopher DuRoss
2015, Bulletin of the Seismological Society of America (105) 2354-2366
Photomosaics are commonly used to construct maps of paleoseismic trench exposures, but the conventional process of manually using image‐editing software is time consuming and produces undesirable artifacts and distortions. Herein, we document and evaluate the application of image‐based modeling (IBM) for creating photomosaics and 3D models of paleoseismic trench exposures,...
Spatial patterns of atmospheric deposition of nitrogen and sulfur using ion-exchange resin collectors in Rocky Mountain National Park, USA
David W. Clow, Heidi Roop, Leora Nanus, Mark Fenn, Graham A. Sexstone
2015, Atmospheric Environment (101) 149-157
Lakes and streams in Class 1 wilderness areas in the western United States (U.S.) are at risk from atmospheric deposition of nitrogen (N) and sulfur (S), and protection of these resources is mandated under the Federal Clean Air Act and amendments. Assessment of critical loads, which are the maximum exposure...
Plague bacterium as a transformer species in prairie dogs and the grasslands of western North America
David A. Eads, Dean E. Biggins
2015, Conservation Biology (29) 1086-1093
Invasive transformer species change the character, condition, form, or nature of ecosystems and deserve considerable attention from conservation scientists. We applied the transformer species concept to the plague bacterium Yersinia pestis in western North America, where the pathogen was introduced around 1900. Y. pestis transforms grassland ecosystems by severely depleting the abundance...
Fishes of the Blackwater River Drainage, Tucker County, West Virginia
Daniel A. Cincotta, Stuart A. Welsh, Douglas P. Wegman, Thomas E. Oldham, Lara B. Hedrick
2015, Southeastern Naturalist (14) 297-313
The Blackwater River, a tributary of the upper Cheat River of the Monongahela River, hosts a modest fish fauna. This relatively low diversity of fish species is partly explained by its drainage history. The Blackwater was once part of the prehistoric, northeasterly flowing St. Lawrence River. During the Pleistocene Epoch,...
Hydrodynamic modeling to evaluate the influence of constructed side-channel habitat on larval drift of pallid strugeon in the Lower Missouri River
Susannah O. Erwin, Robert B. Jacobson
2015, Conference Paper, Proceedings of the joint federal interagency conference 2015: Proceedings of papers of the 5th federal interagency hydrologic modeling conference and the 10th federal interagency sedimentation conference (Proceedings of the 3rd joint federal interagency conference on sedimentation and hydrologic modeling)
Larval drift is a critical phase of ontogeny for many species of lotic fishes. Downstream advection and dispersion of drifting larvae or eggs is controlled by the complex interaction of flow regime, channel planform, local channel morphology, and the resulting hydraulic gradients. In many regulated rivers, channel engineering and perturbations...
The origin of Mauna Loa's Nīnole Hills: Evidence of rift zone reorganization
Jeffrey Zurek, Glyn Williams-Jones, Frank A. Trusdell, Simon Martin
2015, Geophysical Research Letters (42) 8358-8366
In order to identify the origin of Mauna Loa volcano's Nīnole Hills, Bouguer gravity was used to delineate density contrasts within the edifice. Our survey identified two residual anomalies beneath the Southwest Rift Zone (SWRZ) and the Nīnole Hills. The Nīnole Hills anomaly is elongated, striking northeast, and in inversions...
Influence of Smallmouth Bass predation on recruitment of age-0 Yellow Perch in South Dakota glacial lakes
Daniel J. Dembkowski, D.W. Willis, B. G. Blackwell, Steven R. Chipps, T. D. Bacula, M.R. Wuellner
2015, North American Journal of Fisheries Management (35) 736-747
We estimated the influence of predation by Smallmouth Bass Micropterus dolomieu on recruitment of age-0 Yellow Perch Perca flavescens in two northeastern South Dakota glacial lakes. We estimated a likely range in consumption of age-0 Yellow Perch using Smallmouth Bass diet information from two time periods when age-0 Yellow Perch...
Climate change and vulnerability of bull trout (Salvelinus confluentus) in a fire-prone landscape.
Jeffrey A. Falke, Rebecca L. Flitcroft, Jason B. Dunham, Kristina M. McNyset, Paul F. Hessburg, Gordon H. Reeves
2015, Canadian Journal of Fisheries and Aquatic Sciences (72) 304-318
Linked atmospheric and wildfire changes will complicate future management of native coldwater fishes in fire-prone landscapes, and new approaches to management that incorporate uncertainty are needed to address this challenge. We used a Bayesian network (BN) approach to evaluate population vulnerability of...
Hydrogeologic map of the Islamic Republic of Mauritania (phase V, deliverable 56), Synthesis of hydrologic data (phase V, deliverable 57), and chemical hydrologic map of the Islamic Republic of Mauritania (added value)
Michael J. Friedel, Carol A. Finn, John D. Horton
2015, Open-File Report 2013-1280-C
A hydrogeologic study was conducted to support mineral-resource assessment activities in Mauritania, Africa. Airborne magnetic depth estimates reveal two primary groundwater basins: the porous coastal Continental Terminal Basin (fill deposits); and the interior, fractured interior Taoudeni Basin. In the Continental Terminal Basin, there is uniform vertical recharge and localized discharge...
Paleoseismic evidence for late Holocene tectonic deformation along the Saddle mountain fault zone, Southeastern Olympic Peninsula, Washington
Elizabeth Barnett, Brian L. Sherrod, Jonathan F. Hughes, Harvey M. Kelsey, Jessica L. Czajkowski, Timothy J. Walsh, Trevor A. Contreras, Elizabeth R. Schermer, Robert J. Carson
2015, Bulletin of the Seismological Society of America (105) 38-71
Trench and wetland coring studies show that northeast‐striking strands of the Saddle Mountain fault zone ruptured the ground about 1000 years ago, generating prominent scarps. Three conspicuous subparallel fault scarps can be traced for 15 km on Light Detection and Ranging (LiDAR) imagery, traversing the foothills of the southeast Olympic Mountains:...
Evaluation of stream flow effects on smolt survival in the Yakima River Basin, Washington, 2012-2014
Ian Courter, Tommy Garrison, Tobias J. Kock, Russell W. Perry
2015, Report
The influence of stream flow on survival of emigrating juvenile (smolts) Pacific salmon Oncorhynchus spp. and steelhead trout O. mykiss is of key management interest. However, few studies have quantified flow effects on smolt migration survival, and available information does not indicate a consistent flow-survival relationship within the typical range...
Copper toxicity and organic matter: Resiliency of watersheds in the Duluth Complex, Minnesota, USA
Nadine M. Piatak, Robert R. Seal, Perry M. Jones, Laurel G. Woodruff
2015, Conference Paper, Proceedings of the 10th International Conference on Acid Rock Drainage and IMWA Annual Conference
We estimated copper (Cu) toxicity in surface water with high dissolved organic matter (DOM) for unmined mineralized watersheds of the Duluth Complex using the Biotic Ligand Model (BLM), which evaluates the effect of DOM, cation competition for biologic binding sites, and metal speciation. A sediment-based BLM was used to estimate...
Climate tolerances and habitat requirements jointly shape the elevational distribution of the American Pika (Ochotona princeps), with implications for climate change effects
Leah H. Yandow, Anna D. Chalfoun, Daniel F. Doak
2015, PLoS ONE (10) 1-21
Some of the most compelling examples of ecological responses to climate change are elevational range shifts of individual species, which have been observed throughout the world. A growing body of evidence, however, suggests substantial mediation of simple range shifts due to climate change by other limiting factors. Understanding limiting factors...
Identifying sediment sources in the sediment TMDL process
Allen C. Gellis, Faith A. Fitzpatrick, Joseph P. Schubauer-Berigan, R.B. Landy, Lillian E. Gorman Sanisaca
2015, Conference Paper, Proceedings of the 3rd Joint Federal Interagency Conference (10th Federal Interagency Sedimentation Conference and 5th Federal Interagency Hydrologic Modeling Conference)
Sediment is an important pollutant contributing to aquatic-habitat degradation in many waterways of the United States. This paper discusses the application of sediment budgets in conjunction with sediment fingerprinting as tools to determine the sources of sediment in impaired waterways. These approaches complement monitoring, assessment, and modeling of sediment erosion,...
Non-perturbational surface-wave inversion: A Dix-type relation for surface waves
Matthew M. Haney, Victor C. Tsai
2015, Geophysics (80) EN167-EN177
We extend the approach underlying the well-known Dix equation in reflection seismology to surface waves. Within the context of surface wave inversion, the Dix-type relation we derive for surface waves allows accurate depth profiles of shear-wave velocity to be constructed directly from phase velocity data, in contrast to perturbational methods....
Small lakes show muted climate change signal in deepwater temperatures
Luke A. Winslow, Jordan S. Read, Gretchen J. A. Hansen, Paul C. Hanson
2015, Geophysical Research Letters (42) 355-361
Water temperature observations were collected from 142 lakes across Wisconsin, USA, to examine variation in temperature of lakes exposed to similar regional climate. Whole lake water temperatures increased across the state from 1990 to 2012, with an average trend of 0.042°C yr−1 ± 0.01°C yr−1. In large (>0.5 km2) lakes, the positive temperature trend was...
Estimating switchgrass productivity in the Great Plains using satellite vegetation index and site environmental variables
Yingxin Gu, Bruce K. Wylie, Daniel M. Howard
2015, Ecological Indicators (48) 472-476
Switchgrass is being evaluated as a potential feedstock source for cellulosic biofuels and is being cultivated in several regions of the United States. The recent availability of switchgrass land cover maps derived from the National Agricultural Statistics Service cropland data layer for the conterminous United States provides an opportunity to...
Analysis and selection of magnitude relations for the Working Group on Utah Earthquake Probabilities
Christopher DuRoss, Susan Olig, David Schwartz
2015, Conference Paper, Basin and Range Province Seismic Hazards Summit III, Utah Geological Survey Miscellaneous Publication 15-5
Prior to calculating time-independent and -dependent earthquake probabilities for faults in the Wasatch Front region, the Working Group on Utah Earthquake Probabilities (WGUEP) updated a seismic-source model for the region (Wong and others, 2014) and evaluated 19 historical regressions on earthquake magnitude (M). These regressions relate M to fault parameters...
Geologic map of Mauritania (phase V, deliverables 51a, 51b, and 51c)
Dwight Bradley, Holly Motts, John D. Horton, Stuart A. Giles, Cliff D. Taylor
2015, Open-File Report 2013-1280-A1
In 1996, at the request of the Government of the Islamic Republic of Mauritania, a team of U.S. Geological Survey (USGS) scientists produced a strategic plan for the acquisition, improvement and modernization of multidisciplinary sets of data to support the growth of the Mauritanian minerals sector and to highlight the...
Quantifying stream thermal regimes at management-pertinent scales: combining thermal infrared and stationary stream temperature data in a novel modeling framework.
Shane J. Vatland, Robert E. Gresswell, Geoffrey C. Poole
2015, Water Resources Research (51) 31-46
Accurately quantifying stream thermal regimes can be challenging because stream temperatures are often spatially and temporally heterogeneous. In this study, we present a novel modeling framework that combines stream temperature data sets that are continuous in either space or time. Specifically, we merged the fine spatial resolution of thermal infrared...
Robust global ocean cooling trend for the pre-industrial Common Era
Helen V. McGregor, Michael N. Evans, Hugues Goosse, Guillaume Leduc, Belen Martrat, Jason A. Addison, P. Graham Mortyn, Delia W. Oppo, Marit-Solveig Seidenkrantz, Marie-Alexandrine Sicre, Steven J. Phipps, Kandasamy Selvaraj, Kaustubh Thirumalai, Helena L. Filipsson, Vasile Ersek
2015, Nature Geoscience (8) 671-677
The oceans mediate the response of global climate to natural and anthropogenic forcings. Yet for the past 2,000 years — a key interval for understanding the present and future climate response to these forcings — global sea surface temperature changes and the underlying driving mechanisms are poorly constrained. Here we...