Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 12 of 12
Full-Text Articles in Earth Sciences
Prairie Wetlands Are Important For Carbon Storage, Jay Hestbeck
Prairie Wetlands Are Important For Carbon Storage, Jay Hestbeck
Publications of the US Geological Survey
USGS’s Northern Prairie Wildlife Research Center and USDA’s Agricultural Research Service collaborated to study the potential of prairie pothole region wetlands to sequester carbon emitted into the atmosphere from the burning of fossil fuels. Results suggest that wetlands traditionally functioned as sinks for atmospheric carbon, but cultivation, the current principal land use, has shifted their function to be sources of atmospheric carbon. Data suggest that equal or greater amounts of atmospheric carbon can be stored in wetlands through restoration programs when compared with cropland, even though the acreage of wetlands is much smaller. These restored wetlands will also provide improved …
Characterization Of Ground-Water Quality, Upper Republican Natural Resources District, Nebraska, 1998–2001, Jill D. Frankforter, Daniele T. Chafin
Characterization Of Ground-Water Quality, Upper Republican Natural Resources District, Nebraska, 1998–2001, Jill D. Frankforter, Daniele T. Chafin
Publications of the US Geological Survey
Nearly all rural inhabitants and livestock in the Upper Republican Natural Resources District (URNRD) in southwestern Nebraska use ground water that can be affected by elevated nitrate concentrations. The development of ground-water irrigation in this area has increased the vulnerability of ground water to the introduction of fertilizers and other agricultural chemicals. In 1998, the U.S. Geological Survey, in cooperation with the Upper Republican Natural Resources District, began a study to characterize the quality of ground water in the Upper Republican Natural Resources District area with respect to physical properties and concentrations of major ions, coliform bacteria, nitrate, and pesticides, …
Stream Bank Stability In Eastern Nebraska, Philip J. Soenksen, Mary J. Turner, Benjamin J. Dietsch, Andrew Simon
Stream Bank Stability In Eastern Nebraska, Philip J. Soenksen, Mary J. Turner, Benjamin J. Dietsch, Andrew Simon
Publications of the US Geological Survey
Dredged and straightened channels in eastern Nebraska have experienced degradation leading to channel widening by bank failure. Degradation has progressed headward and affected the drainage systems upstream from the modified reaches. This report describes a study that was undertaken to analyze bank stability at selected sites in eastern Nebraska and develop a simplified method for estimating the stability of banks at future study sites. Bank cross sections along straight reaches of channel and geotechnical data were collected at approximately 150 sites in 26 counties of eastern Nebraska. The sites were categorized into three groups based on mapped soil permeability. With …
Characterization Of Ground-Water Quality, Upper Republican Natural Resources District,Nebraska, 1998 2001, Jill D. Frankforter, Daniele T. Chafin
Characterization Of Ground-Water Quality, Upper Republican Natural Resources District,Nebraska, 1998 2001, Jill D. Frankforter, Daniele T. Chafin
Publications of the US Geological Survey
Nearly all rural inhabitants and livestock in the Upper Republican Natural Resources District (URNRD) in southwestern Nebraska use ground water that can be affected by elevated nitrate concentrations. The development of ground-water irrigation in this area has increased the vulnerability of ground water to the introduction of fertilizers and other agricultural chemicals. In 1998, the U.S. Geological Survey, in cooperation with the Upper Republican Natural Resources District, began a study to characterize the quality of ground water in the Upper Republican Natural Resources District area with respect to physical properties and concentrations of major ions, coliform bacteria, nitrate, and pesticides, …
Sediment Grain-Size And Loss-On-Ignition Analyses From 2002 Englebright Lake Coring And Sampling Campaigns, Noah P. Snyder, James R. Allen, Carlin Dare, Margaret A. Hampton, Gary Schneider, Ryan J. Wooley, Charles N. Alpers, Mark C. Marvin-Dipasquale
Sediment Grain-Size And Loss-On-Ignition Analyses From 2002 Englebright Lake Coring And Sampling Campaigns, Noah P. Snyder, James R. Allen, Carlin Dare, Margaret A. Hampton, Gary Schneider, Ryan J. Wooley, Charles N. Alpers, Mark C. Marvin-Dipasquale
Publications of the US Geological Survey
This report presents sedimentologic data from three 2002 sampling campaigns conducted in Englebright Lake on the Yuba River in northern California. This work was done to assess the properties of the material deposited in the reservoir between completion of Englebright Dam in 1940 and 2002, as part of the Upper Yuba River Studies Program. Included are the results of grain-size-distribution and loss-on-ignition analyses for 561 samples, as well as an error analysis based on replicate pairs of subsamples.
Summary Of Total Mercury Concentrations In Fillets Of Selected Sport Fishes Collected During 2000–2003 From Lake Natoma, Sacramento County, California, Michael K. Saiki, Darell G. Slotten, Thomas W. May, Shaun M. Ayers, Charles N. Alpers
Summary Of Total Mercury Concentrations In Fillets Of Selected Sport Fishes Collected During 2000–2003 From Lake Natoma, Sacramento County, California, Michael K. Saiki, Darell G. Slotten, Thomas W. May, Shaun M. Ayers, Charles N. Alpers
Publications of the US Geological Survey
This report summarizes results of total mercury measurements in skinless fillets of sport fishes collected during August 2000, September–October 2002, and July 2003 from Lake Natoma, a small (8,760 acre-feet) afterbay for Folsom Dam on the lower American River. The primary objective of the study was to determine if mercury concentrations in fillets approached or exceeded guidelines for human consumption. The Food and Drug Administration (FDA) human-health action level for methylmercury in commercially caught fish is 1.0 μg/g (microgram per gram); the U.S. Environmental Protection Agency (USEPA) human-health criterion for methylmercury residue in fish tissue is 0.30 μg/g. Wet weight …
Mercury And Methylmercury Concentrations And Loads In The Cache Creek Basin, California, January 2000 Through May 2001, Joseph L. Domagalski, Charles N. Alpers, Darell G. Slotton, Thomas H. Suchanek, Shaun M. Ayers
Mercury And Methylmercury Concentrations And Loads In The Cache Creek Basin, California, January 2000 Through May 2001, Joseph L. Domagalski, Charles N. Alpers, Darell G. Slotton, Thomas H. Suchanek, Shaun M. Ayers
Publications of the US Geological Survey
Concentrations and mass loads of total mercury and methylmercury in streams draining abandoned mercury mines and near geothermal discharge in the Cache Creek Basin, California, were measured during a 17-month period from January 2000 through May 2001. Rainfall and runoff averages during the study period were lower than long-term averages. Mass loads of mercury and methylmercury from upstream sources to downstream receiving waters, such as San Francisco Bay, were generally the highest during or after winter rainfall events. During the study period, mass loads of mercury and methylmercury from geothermal sources tended to be greater than those from abandoned mining …
Geochemistry Of Mercury And Other Trace Elements In Fluvial Tailings Upstream Of Daguerre Point Dam, Yuba River, California, August 2001, Michael P. Hunerlach, Charles N. Alpers, Mark Marvin-Dipasquale, Howard E. Taylor, John F. De Wild
Geochemistry Of Mercury And Other Trace Elements In Fluvial Tailings Upstream Of Daguerre Point Dam, Yuba River, California, August 2001, Michael P. Hunerlach, Charles N. Alpers, Mark Marvin-Dipasquale, Howard E. Taylor, John F. De Wild
Publications of the US Geological Survey
This study was designed to characterize the particle-size distribution and the concentrations of total mercury (HgT), methylmercury (MeHg), and other constituents in sediments trapped behind Daguerre Point Dam, a 28-foot-high structure on the lower Yuba River in California. The results of the study will assist other agencies in evaluating potential environmental impacts from mobilization of sediments if Daguerre Point Dam is modified or removed to improve the passage of anadromous fish. Methylmercury is of particular concern owing to its toxicity and propensity to bioaccumulate. A limited amount of recent work on hydraulic and dredge tailings in other watersheds has indicated …
Report On The May-June 2002 Englebright Lake Deep Coring Campaign, Noah P. Snyder, Charles N. Alpers, Lorraine E. Flint, Jennifer A. Curtis, Margaret A. Hampton, Brian J. Haskell, Dennis L. Nielson
Report On The May-June 2002 Englebright Lake Deep Coring Campaign, Noah P. Snyder, Charles N. Alpers, Lorraine E. Flint, Jennifer A. Curtis, Margaret A. Hampton, Brian J. Haskell, Dennis L. Nielson
Publications of the US Geological Survey
This report describes the May-June 2002 Englebright Lake coring project. Englebright Lake is a 14-km-long reservoir on the Yuba River of northern California, impounded by Englebright Dam, which was completed in 1940. The sediments were cored to assess the current conditions in the reservoir as part of the California Bay-Delta Authority’s Upper Yuba River Studies Program. Sediment was collected using both hydraulic-piston and rotational coring equipment mounted on a floating drilling platform. Thirty boreholes were attempted at 7 sites spaced along the longitudinal axis of the reservoir. Complete sedimentary sections were recovered from 20 boreholes at 6 sites. In total, …
Geochemical Characterization Of Water, Sediment, And Biota Affected By Mercury Contamination And Acidic Drainage From Historical Gold Mining, Greenhorn Creek, Nevada County, California, 1999-2001, Charles N. Alpers, Michael P. Hunerlach, Jason T. May, Roger L. Hothem, Howard E. Taylor, Ronald C. Antweiler, John F. De Wild, David A. Lawler
Geochemical Characterization Of Water, Sediment, And Biota Affected By Mercury Contamination And Acidic Drainage From Historical Gold Mining, Greenhorn Creek, Nevada County, California, 1999-2001, Charles N. Alpers, Michael P. Hunerlach, Jason T. May, Roger L. Hothem, Howard E. Taylor, Ronald C. Antweiler, John F. De Wild, David A. Lawler
Publications of the US Geological Survey
In 1999, the U.S. Geological Survey (USGS) initiated studies of mercury and methylmercury occurrence, transformation, and transport in the Bear River and Yuba River watersheds of the northwestern Sierra Nevada. Because these watersheds were affected by large-scale, historical gold extraction using mercury amalgamation beginning in the 1850s, they were selected for a pilot study of mercury transport by the USGS and other cooperating agencies. This report presents data on methylmercury (MeHg) and total mercury (THg) concentrations in water, bed sediment, invertebrates, and frogs collected at 40 stations during 1999−2001 in the Greenhorn Creek drainage, a major tributary to the Bear …
Simulation Of Ground-Water Flow In The Cedar River Alluvial Aquifer Flow System, Cedar Rapids, Iowa Scientific
Publications of the US Geological Survey
The Cedar River alluvial aquifer is the primary source of municipal water in the Cedar Rapids, Iowa, area. Since 1992, the U.S. Geological Survey, in cooperation with the City of Cedar Rapids, has investigated the hydrogeology and water quality of the Cedar River alluvial aquifer. This report describes a detailed analysis of the ground-water flow system in the alluvial aquifer, particularly near well field areas.
The ground-water flow system in the Cedar Rapids area consists of two main components, the unconsolidated Quaternary deposits and the underlying carbonate bedrock that has a variable fracture density. Quaternary deposits consist of eolian sand, …
Mute Swans And Their Chesapeake Bay Habitats:Proceedings Of A Symposium, Matthew C. Perry
Mute Swans And Their Chesapeake Bay Habitats:Proceedings Of A Symposium, Matthew C. Perry
Publications of the US Geological Survey
The symposium “Mute Swans and their Chesapeake Bay Habitats,” held on June 7, 2001, provided a forum for biologists and managers to share research findings and management ideas concerning the exotic and invasive mute swan (Cygnus olor). This species has been increasing in population size and is considered by many to be a problem in regard to natural food resources in the Bay that are used by native waterfowl during the winter months. Other persons, however, feel that resource managers are attempting to create a problem to justify more killing of waterfowl by hunters. Some persons also believe …