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

10951 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 129, results 3201 - 3225

Show results on a map

Publication Extents

Not all publications have extents, not all extents are completely accurate
Instrumenting caves to collect hydrologic and geochemical data: case study from James Cave, Virginia
Madeline E. Schreiber, Benjamin F. Schwartz, William Orndorff, Daniel H. Doctor, Sarah D. Eagle, Jonathan D. Gerst
2015, Book chapter, Advances in watershed science and assessment
Karst aquifers are productive groundwater systems, supplying approximately 25 % of the world’s drinking water. Sustainable use of this critical water supply requires information about rates of recharge to karst aquifers. The overall goal of this project is to collect long-term, high-resolution hydrologic and geochemical datasets at James Cave, Virginia,...
Large-scale dam removal on the Elwha River, Washington, USA: source-to-sink sediment budget and synthesis
Jonathan A. Warrick, Jennifer A. Bountry, Amy E. East, Christopher S. Magirl, Timothy J. Randle, Guy R. Gelfenbaum, Andrew C. Ritchie, George R. Pess, Vivian Leung, Jeff J. Duda
2015, Geomorphology (246) 729-750
Understanding landscape responses to sediment supply changes constitutes a fundamental part of many problems in geomorphology, but opportunities to study such processes at field scales are rare. The phased removal of two large dams on the Elwha River, Washington, exposed 21 ± 3 million m3, or ~ 30 million tonnes (t), of sediment that had been deposited...
Growth rates and variances of unexploited wolf populations in dynamic equilibria
L. David Mech, John Fieberg
2015, Wildlife Society Bulletin (39) 41-48
Several states have begun harvesting gray wolves (Canis lupus), and these states and various European countries are closely monitoring their wolf populations. To provide appropriate perspective for determining unusual or extreme fluctuations in their managed wolf populations, we analyzed natural, long-term, wolf-population-density trajectories totaling 130 years of data from 3...
The quality of our nation's waters: water quality in the Principal Aquifers of the Piedmont, Blue Ridge, and Valley and Ridge regions, eastern United States, 1993-2009
Bruce D. Lindsey, Tammy M. Zimmerman, Melinda J. Chapman, Charles A. Cravotta III,, Zoltan Szabo
2015, Circular 1354
The aquifers of the Piedmont, Blue Ridge, and Valley and Ridge regions underlie an area with a population of more than 40 million people in 10 states. The suburban and rural population is large, growing rapidly, and increasingly dependent on groundwater as a source of supply, with more than 550...
Hydrogeology of the Ramapo River-Woodbury Creek valley-fill aquifer system and adjacent areas in eastern Orange County, New York
Paul M. Heisig
2015, Scientific Investigations Report 2014-5156
The hydrogeology of the valley-fill aquifer system and surrounding watershed areas was investigated within a 23-mile long, fault-controlled valley in eastern Orange County, New York. Glacial deposits form a divide within the valley that is drained to the north by Woodbury Creek and is drained to the south by the...
Soil greenhouse gas emissions and carbon budgeting in a short-hydroperiod floodplain wetland
Jackie Batson, Gregory B. Noe, Cliff R. Hupp, Ken W. Krauss, Nancy B. Rybicki, Edward R. Schenk
2015, Journal of Geophysical Research: Biogeosciences (120) 77-95
Understanding the controls on floodplain carbon (C) cycling is important for assessing greenhouse gas emissions and the potential for C sequestration in river-floodplain ecosystems. We hypothesized that greater hydrologic connectivity would increase C inputs to floodplains that would not only stimulate soil C gas emissions but also sequester more C...
Patterns of floodplain sediment deposition along the regulated lower Roanoke River, North Carolina: annual, decadal, centennial scales
Cliff R. Hupp, Edward R. Schenk, Daniel Kroes, Debra A. Willard, Phil A. Townsend, Robert K. Peet
2015, Geomorphology (228) 666-680
The lower Roanoke River on the Coastal Plain of North Carolina is not embayed and maintains a floodplain that is among the largest on the mid-Atlantic Coast. This floodplain has been impacted by substantial aggradation in response to upstream colonial and post-colonial agriculture between the mid-eighteenth and mid-nineteenth centuries. Additionally,...
Geochemical evolution of groundwater in the Mud Lake area, eastern Idaho, USA
Gordon W. Rattray
2015, Environmental Earth Sciences (73) 8251-8269
Groundwater with elevated dissolved-solids concentrations—containing large concentrations of chloride, sodium, sulfate, and calcium—is present in the Mud Lake area of Eastern Idaho. The source of these solutes is unknown; however, an understanding of the geochemical sources and processes controlling their presence in groundwater in the Mud Lake area is needed...
Central Appalachian basin natural gas database: distribution, composition, and origin of natural gases
Yomayra A. Roman Colon, Leslie F. Ruppert
2015, Open-File Report 2014-1207
The U.S. Geological Survey (USGS) has compiled a database consisting of three worksheets of central Appalachian basin natural gas analyses and isotopic compositions from published and unpublished sources of 1,282 gas samples from Kentucky, Maryland, New York, Ohio, Pennsylvania, Tennessee, Virginia, and West Virginia. The database includes field and reservoir...
Evaluation of development options for Alaska North Slope viscous and heavy oil
Emil D. Attanasi, Philip A. Freeman
2015, Natural Resources Research (24) 85-106
Current estimates of discovered viscous and heavy oil in Alaska’s North Slope are 12 billion barrels of oil-in-place and 12–18 billion barrels of oil-in-place, respectively (see Appendix 1 for conversion to SI units). Since the early 1990s to the end of 2010, cumulative viscous oil production has amounted to...
Detrital zircon U-Pb provenance of the Colorado River: A 5 m.y. record of incision into cover strata overlying the Colorado Plateau and adjacent regions
David L. Kimbrough, Marty Grove, George E. Gehrels, Rebecca J. Dorsey, Keith A. Howard, Oscar Lovera, Andres Aslan, Kyle House, Philip A. Pearthree
2015, Geosphere (11) 1719-1748
New detrital zircon U-Pb age distributions from 49 late Cenozoic sandstones and Holocene sands (49 samples, n = 3922) record the arrival of extra-regional early Pliocene Colorado River sediment at Grand Wash (western USA) and downstream locations ca. 5.3 Ma and the subsequent evolution of the river’s provenance signature. We...
Simulations of potential future conditions in the cache critical groundwater area, Arkansas
Haveen M. Rashid, Brian R. Clark, Hanan H. Mahdi, Hanadi S. Rifai, Haydar J. Al-Shukri
2015, Environmental & Engineering Geoscience (21) 1-19
A three-dimensional finite-difference model for part of the Mississippi River Valley alluvial aquifer in the Cache Critical Groundwater Area of eastern Arkansas was constructed to simulate potential future conditions of groundwater flow. The objectives of this study were to test different pilot point distributions to find reasonable estimates of aquifer...
Kilauea's 5-9 March 2011 Kamoamoa fissure eruption and its relation to 30+ years of activity from Pu'u 'Ō'ō
Tim R. Orr, Michael P. Poland, Matthew R. Patrick, Weston A. Thelen, A.J. Sutton, Tamar Elias, Carl R. Thornber, Carolyn Parcheta, Kelly M. Wooten
Rebecca Carey, Valerie Cayol, Michael P. Poland, Dominique Weis, editor(s)
2015, Book chapter, Hawaiian volcanoes: From source to surface
Lava output from Kīlauea's long-lived East Rift Zone eruption, ongoing since 1983, began waning in 2010 and was coupled with uplift, increased seismicity, and rising lava levels at the volcano's summit and Pu‘u ‘Ō‘ō vent. These changes culminated in the four-day-long Kamoamoa fissure eruption on the East Rift...
Shippingport, Kentucky, is the type locality for the white-footed mouse, Peromyscus leucopus (Rafinesque, 1818) (Mammalia: Rodentia: Cricetidae)
Neal Woodman
2015, Proceedings of the Biological Society of Washington (182) 152-163
The white-footed mouse, Musculus leucopus Rafinesque, 1818 (= Peromyscus leucopus), is a common small mammal that is widespread in the eastern and central United States. Its abundance in many habitats renders it ecologically important, and its status as a reservoir for hantavirus and Lyme disease gives the species medical and...
Denitrification in the Mississippi River network controlled by flow through river bedforms
Jesus D. Gomez-Velez, Judson W. Harvey, M. Bayani Cardenas, Brian Kiel
2015, Nature Geoscience (8) 941-945
Increasing nitrogen concentrations in the world’s major rivers have led to over-fertilization of sensitive downstream waters. Flow through channel bed and bank sediments acts to remove riverine nitrogen through microbe-mediated denitrification reactions. However, little is understood about where in the channel network this biophysical process is most efficient, why certain...
Evidence for intercontinental parasite exchange through molecular detection and characterization of haematozoa in northern pintails (Anas acuta) sampled throughout the North Pacific Basin
Andrew M. Ramey, Joel A. Schmutz, John A. Reed, Go Fujita, Bradley D. Scotton, Bruce Casler, Joseph P. Fleskes, Kan Konishi, Kiyoshi Uchida, Michael J. Yabsley
2015, International Journal for Parasitology: Parasites and Wildlife (4) 11-21
Empirical evidence supports wild birds as playing a role in the interhemispheric exchange of bacteria and viruses; however, data supporting the redistribution of parasites among continents are limited. In this study, the hypothesis that migratory birds contribute to the redistribution of parasites between continents was tested by sampling northern pintails...
Eocene and Miocene extension, meteoric fluid infiltration, and core complex formation in the Great Basin (Raft River Mountains, Utah)
Katharina Methner, Andreas Mulch, Christian Teyssier, Michael L. Wells, Michael A. Cosca, Raphael Gottardi, Aude Gebelin, C. Page Chamberlain
2015, Tectonics (34) 680-693
Metamorphic core complexes (MCCs) in the North American Cordillera reflect the effects of lithospheric extension and contribute to crustal adjustments both during and after a protracted subduction history along the Pacific plate margin. While the Miocene-to-recent history of most MCCs in the Great Basin, including the Raft River-Albion-Grouse Creek MCC,...
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...
Lake Ontario benthic prey fish assessment, 2014
Brian Weidel, Maureen Walsh
2015, Report, 2014 Annual Report Bureau of Fisheries Lake Ontario Unit and St. Lawrence River Unit to the Great Lakes Fishery Commission’s Lake Ontario Committee
Benthic prey fishes are an important component of the Lake Ontario fish community and serve as vectors that move energy from benthic invertebrates into native and introduced sport fishes. Since the 1970’s, the USGS Lake Ontario Biological Station has assessed benthic fish populations and community dynamics with bottom trawls at...
Hydrothermal, biogenic, and seawater components in metalliferous black shales of the Brooks Range, Alaska: Synsedimentary metal enrichment in a carbonate ramp setting
John F. Slack, David Selby, Julie A. Dumoulin
2015, Economic Geology (110) 653-675
Trace element and Os isotope data for Lisburne Group metalliferous black shales of Middle Mississippian (early Chesterian) age in the Brooks Range of northern Alaska suggest that metals were sourced chiefly from local seawater (including biogenic detritus) but also from externally derived hydrothermal fluids. These black shales are interbedded with...
Songbirds as sentinels of mercury in terrestrial habitats of eastern North America
Allyson K. Jackson, David C. Evers, Evan M. Adams, Daniel A. Cristol, Collin A. Eagles-Smith, Samuel T. Edmonds, Carrie E. Gray, Bart Hoskins, Oksana P. Lane, Amy Sauer, Timothy Tear
2015, Ecotoxicology (24) 453-467
Mercury (Hg) is a globally distributed environmental contaminant with a variety of deleterious effects in fish, wildlife, and humans. Breeding songbirds may be useful sentinels for Hg across diverse habitats because they can be effectively sampled, have well-defined and small territories, and can integrate pollutant exposure over time and space....
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...
Monitoring Eastern Spadefoot (Scaphiopus holbrookii) response to weather with the use of a passive integrated transponder (PIT) system
Kevin J. Ryan, Aram J.K. Calhoun, Brad C. Timm, Joseph D. Zydlewski
2015, Journal of Herpetology (49) 257-263
Eastern Spadefoots (Scaphiopus holbrookii) are probably one of the least-understood amphibian species in the United States. In New England, populations are localized and it is likely that some populations go undocumented because of the species' cryptic habits. We used passive integrated transponders (PIT tags) to monitor burrow emergence with the...
Net ecosystem production and organic carbon balance of U.S. East Coast estuaries: A synthesis approach
Maria Herrmann, Raymond G. Najjar, W. Michael Kemp, Richard B. Alexander, Elizabeth W. Boyer, Wei-Jun Cai, Peter C. Griffith, Kevin D. Kroeger, S. Leigh McCallister, Richard A. Smith
2015, Global Biogeochemical Cycles (29) 96-111
Net ecosystem production (NEP) and the overall organic carbon budget for the estuaries along the East Coast of the United States are estimated. We focus on the open estuarine waters, excluding the fringing wetlands. We developed empirical models relating NEP to loading ratios of dissolved inorganic nitrogen to total organic...
Use of flux and morphologic sediment budgets for sandbar monitoring on the Colorado River in Marble Canyon, Arizona
Paul E. Grams, Daniel D. Buscombe, David J. Topping, Joseph E. Hazel Jr., Matt Kaplinski
2015, Conference Paper, Proceedings of the joint federal interagency conference 2015
The magnitude and pfattern of streamflow and sediment supply of the Colorado River in Grand Canyon (Figure 1) has been affected by the existence and operations of Glen Canyon Dam since filling of Lake Powell Reservoir began in March 1963. In the subsequent 30 years, fine sediment was scoured from...