Skip to main content
U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Results

165621 results.

Alternate formats: RIS file of the first 3000 search results  |  Download all results as CSV | TSV | Excel  |  RSS feed based on this search  |  JSON version of this page of results

Page 1330, results 33226 - 33250

Show results on a map

Publication Extents

Not all publications have extents, not all extents are completely accurate
Water resources of De Soto Parish, Louisiana
Lawrence B. Prakken, Vincent E. White
2014, Fact Sheet 2013-3107
Information concerning the availability, use, and quality of water in De Soto Parish, Louisiana, is critical for proper water-supply management. The purpose of this fact sheet is to present information that can be used by water managers, parish residents, and others for stewardship of this vital resource. Information on the...
Three-dimensional seismic velocity structure and earthquake relocations at Katmai, Alaska
Rachel Murphy, Clifford Thurber, Stephanie G. Prejean, Ninfa Bennington
2014, Journal of Volcanology and Geothermal Research (276) 121-131
We invert arrival time data from local earthquakes occurring between September 2004 and May 2009 to determine the three-dimensional (3D) upper crustal seismic structure in the Katmai volcanic region. Waveforms for the study come from the Alaska Volcano Observatory's permanent network of 20 seismic stations in the area (predominantly single-component,...
Seismicity and seismic structure at Okmok Volcano, Alaska
Summer J. Ohlendorf, Clifford H. Thurber, Jeremy D. Pesicek, Stephanie G. Prejean
2014, Journal of Volcanology and Geothermal Research (278-279) 103-119
Okmok volcano is an active volcanic caldera located on the northeastern portion of Umnak Island in the Aleutian arc, with recent eruptions in 1997 and 2008. The Okmok area had ~900 locatable earthquakes between 2003 and June 2008, and an additional ~600 earthquakes from the beginning of the 2008 eruption...
Accuracy assessment of the U.S. Geological Survey National Elevation Dataset, and comparison with other large-area elevation datasets: SRTM and ASTER
Dean B. Gesch, Michael J. Oimoen, Gayla A. Evans
2014, Open-File Report 2014-1008
The National Elevation Dataset (NED) is the primary elevation data product produced and distributed by the U.S. Geological Survey. The NED provides seamless raster elevation data of the conterminous United States, Alaska, Hawaii, U.S. island territories, Mexico, and Canada. The NED is derived from diverse source datasets that are processed...
The search for geologic evidence of distant-source tsunamis using new field data in California
Rick Wilson, Eileen Hemphill-Haley, Bruce Jaffe, Bruce Richmond, Robert Peters, Nick Graehl, Harvey Kelsey, Robert Leeper, Steve Watt, Mary McGann, Don F. Hoirup, Catherine Chague-Goff, James Goff, Dylan Caldwell, Casey Loofbourrow
2014, Open-File Report 2013-1170-C
A statewide assessment for geological evidence of tsunamis, primarily from distant-source events, found tsunami deposits at several locations, though evidence was absent at most locations evaluated. Several historical distant-source tsunamis, including the 1946 Aleutian, 1960 Chile, and 1964 Alaska events, caused inundation along portions of the northern and central California...
Impacts of white-tailed deer on red trillium (Trillium recurvatum): defining a threshold for deer browsing pressure at the Indiana Dunes National Lakeshore
Noel B. Pavlovic, Stacey A. Leicht-Young, Ralph Grundel
2014, Scientific Investigations Report 2014-5070
Overabundant white-tailed deer (Odocoileus virginianus) have been a concern for land managers in eastern North America because of their impacts on native forest ecosystems. Managers have sought native plant species to serve as phytoindicators of deer impacts to supplement deer surveys. We analyzed experimental data about red trillium (Trillium recurvatum),...
Post-earthquake relaxation using a spectral element method: 2.5-D case
Frederick Pollitz
2014, Geophysical Journal International (198) 308-326
The computation of quasi-static deformation for axisymmetric viscoelastic structures on a gravitating spherical earth is addressed using the spectral element method (SEM). A 2-D spectral element domain is defined with respect to spherical coordinates of radius and angular distance from a pole of symmetry, and 3-D viscoelastic structure is assumed...
Geochemical and mineralogical maps for soils of the conterminous United States
David B. Smith, William F. Cannon, Laurel G. Woodruff, Federico Solano, Karl J. Ellefsen
2014, Open-File Report 2014-1082
The U.S. Geological Survey began sampling in 2007 for a low-density (1 site per 1,600 square kilometers, 4,857 sites) geochemical and mineralogical survey of soils in the conterminous United States as part of the North American Soil Geochemical Landscapes Project. The sampling protocol for the national-scale survey included, at each...
Creating a monthly time series of the potentiometric surface in the Upper Floridan aquifer, Northern Tampa Bay area, Florida, January 2000-December 2009
Terrie M. Lee, Geoffrey G. Fouad
2014, Scientific Investigations Report 2014-5038
In Florida’s karst terrain, where groundwater and surface waters interact, a mapping time series of the potentiometric surface in the Upper Floridan aquifer offers a versatile metric for assessing the hydrologic condition of both the aquifer and overlying streams and wetlands. Long-term groundwater monitoring data were used to generate a...
An individual-based growth and competition model for coastal redwood forest restoration
Phillip J. van Mantgem, Adrian J. Das
2014, Canadian Journal of Forest Research (44) 1051-1057
Thinning treatments to accelerate coastal redwood forest stand development are in wide application, but managers have yet to identify prescriptions that might best promote Sequoia sempervirens (Lamb. ex D. Don) Endl. (redwood) growth. The creation of successful thinning prescriptions would be aided by identifying the underlying mechanisms governing how individual tree growth...
Freshwater availability and coastal wetland foundation species: ecological transitions along a rainfall gradient
Michael J. Osland, Nicholas M. Enwright, Camille L. Stagg
2014, Ecology (95) 2789-2802
Climate gradient-focused ecological research can provide a foundation for better understanding critical ecological transition points and nonlinear climate-ecological relationships, which is information that can be used to better understand, predict, and manage ecological responses to climate change. In this study, we examined the influence of freshwater availability upon the coverage...
Beach science in the Great Lakes
Meredith B. Nevers, Murulee N. Byappanahalli, Thomas A. Edge, Richard L. Whitman
2014, Journal of Great Lakes Research (40) 1-14
Monitoring beach waters for human health has led to an increase and evolution of science in the Great Lakes, which includes microbiology, limnology, hydrology, meteorology, epidemiology, and metagenomics, among others. In recent years, concerns over the accuracy of water quality standards at protecting human health have led to a significant...
Home range characteristics of Mexican Spotted Owls in the Rincon Mountains, Arizona
David W. Willey, Charles van Riper III
2014, Wilson Journal of Ornithology (126) 53-59
We studied a small isolated population of Mexican Spotted Owls (Strix occidentalis lucida) from 1996–1997 in the Rincon Mountains of Saguaro National Park, southeastern Arizona, USA. All mixed-conifer and pine-oak forest patches in the park were surveyed for Spotted Owls, and we located, captured, and radio-tagged 10 adult birds representing...
The distribution and extent of heavy metal accumulation in song sparrows along Arizona's upper Santa Cruz River
Michael B. Lester, Charles van Riper III
2014, Environmental Monitoring and Assessment (186) 4779-4791
Heavy metals are persistent environmental contaminants, and transport of metals into the environment poses a threat to ecosystems, as plants and wildlife are susceptible to long-term exposure, bioaccumulation, and potential toxicity. We investigated the distribution and cascading extent of heavy metal accumulation in southwestern song sparrows (Melospiza melodia fallax), a...
Factors affecting public-supply well vulnerability in two karst aquifers
MaryLynn Musgrove, Brian G. Katz, Lynne S. Fahlquist, Christy A. Crandall, Richard J. Lindgren
2014, Ground Water (52) 63-75
Karst aquifers occur in a range of climatic and geologic settings. Nonetheless, they are commonly characterized by their vulnerability to water-quality impairment. Two karst aquifers, the Edwards aquifer in south-central Texas and the Upper Floridan aquifer in western Florida, were investigated to assess factors that control the movement of contaminants...
Mercury concentrations in water, and mercury and selenium concentrations in fish from Brownlee Reservoir and selected sites in Boise and Snake Rivers, Idaho and Oregon, 2013
Dorene E. MacCoy
2014, Open-File Report 2014-1099
Mercury (Hg) analyses were conducted on samples of sport fish and water collected from six sampling sites in the Boise and Snake Rivers, and Brownlee Reservoir to meet National Pollution Discharge and Elimination System (NPDES) permit requirements for the City of Boise, Idaho. A water sample was collected from each...
Sea otters are recolonizing southern California in fits and starts
Kevin D. Lafferty, M. Tim Tinker
2014, Ecosphere (5)
After near extinction as a result of the fur trade in the 1700s and 1800s, the southern sea otter slowly reoccupied the core of its range in central California. Range expansion beyond central California is seen as key to full recovery of otters, but the rate of expansion has been...
Cruise report for P1-13-LA, U.S. Geological Survey gas hydrates research cruise, R/V Pelican April 18 to May 3, 2013, deepwater Gulf of Mexico
Seth S. Haines, Patrick E. Hart, Carolyn Ruppel, Thomas O'Brien, Wayne Baldwin, Jenny White, Eric Moore, Peter Dal Ferro, Peter Lemmond
2014, Open-File Report 2014-1080
The U.S. Geological Survey led a seismic acquisition cruise in the Gulf of Mexico from April 18 to May 3, 2013, with the objectives of (1) achieving improved imaging and characterization at two established gas hydrate study sites, and (2) refining geophysical methods for gas hydrate characterization in other locations....
Bathymetry and acoustic backscatter: outer mainland shelf and slope, Gulf of Santa Catalina, southern California
Peter Dartnell, James E. Conrad, Holly F. Ryan, David P. Finlayson
2014, Open-File Report 2014-1094
In 2010 and 2011, scientists from the U.S. Geological Survey (USGS), Coastal and Marine Geology Program, acquired bathymetry and acoustic-backscatter data from the outer shelf and slope region offshore of southern California. The surveys were conducted as part of the USGS Marine Geohazards Program. Assessment of the hazards posed by...
Earthquake catalog for estimation of maximum earthquake magnitude, Central and Eastern United States: Part A, Prehistoric earthquakes
Russell L. Wheeler
2014, Open-File Report 2014-1025-A
Computation of probabilistic earthquake hazard requires an estimate of Mmax, the maximum earthquake magnitude thought to be possible within a specified geographic region. This report is Part A of an Open-File Report that describes the construction of a global catalog of moderate to large earthquakes, from which one can estimate...
Distribution and landscape controls of organic layer thickness and carbon within the Alaskan Yukon River Basin
Neal J. Pastick, Matthew B. Rigge, Bruce K. Wylie, M. Torre Jorgenson, Joshua R. Rose, Kristofer D. Johnson, Lei Ji
2014, Geoderma (230-231) 79-94
Understanding of the organic layer thickness (OLT) and organic layer carbon (OLC) stocks in subarctic ecosystems is critical due to their importance in the global carbon cycle. Moreover, post-fire OLT provides an indicator of long-term successional trajectories and permafrost susceptibility to thaw. To these ends, we 1) mapped OLT and...
Water levels and water quality in the Sparta-Memphis aquifer (middle Claiborne aquifer) in Arkansas, spring-summer 2011
T.P. Schrader
2014, Scientific Investigations Report 2014-5044
The U.S. Geological Survey, in cooperation with the Arkansas Natural Resources Commission and the Arkansas Geological Survey, has monitored water levels in the Sparta Sand of Claiborne Group and Memphis Sand of Claiborne Group (herein referred to as “the Sparta Sand” and “the Memphis Sand,” respectively) since the 1920s. Groundwater...
Corticosterone metabolite concentrations in greater sage-grouse are positively associated with the presence of cattle grazing
M.D. Jankowski, Robin E. Russell, J. Christian Franson, Robert J. Dusek, M.K. Hines, M. Gregg, Erik K. Hofmeister
2014, Rangeland Ecology and Management (67) 237-246
The sagebrush biome in the western United States is home to the imperiled greater sage-grouse (Centrocercus urophasianus) and encompasses rangelands used for cattle production. Cattle grazing activities have been implicated in the range-wide decline of the sage-grouse, but no studies have investigated the relationship between the physiological condition of sage-grouse...
Events affecting gold exploration in Venezuela since 1999
David R. Wilburn
2014, Open-File Report 2014-1068
The structure of the gold mining industry in Venezuela has changed significantly since 1999 as a result of Government policy changes and industry response to these changes. This report documents the policy decisions that have affected the mining industry, discusses the response of the industry on a site by site...
Physiological and ecological effects of increasing temperature on fish production in lakes of Arctic Alaska
Michael P. Carey, Christian E. Zimmerman
2014, Ecology and Evolution (4) 1981-1993
Lake ecosystems in the Arctic are changing rapidly due to climate warming. Lakes are sensitive integrators of climate-induced changes and prominent features across the Arctic landscape, especially in lowland permafrost regions such as the Arctic Coastal Plain of Alaska. Despite many studies on the implications of climate warming, how fish...