Reports
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The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
Browse more than 82,000 reports authored by our scientists over the past 100+ year history of the USGS and refine search by topic, location, year, and advanced search.
Filter Total Items: 85231
Descriptive models for epithermal gold-silver deposits Descriptive models for epithermal gold-silver deposits
Epithermal gold-silver deposits are vein, stockwork, disseminated, and replacement deposits that are mined primarily for their gold and silver contents; some deposits also contain substantial resources of lead, zinc, copper, and (or) mercury. These deposits form in the uppermost parts of the crust, at depths less than about 1,500 meters below the water table, and at temperatures below...
Authors
David A. John, Peter G. Vikre, Edward A. du Bray, Richard J. Blakely, David L. Fey, Barnaby W. Rockwell, Jeffrey L. Mauk, Eric D. Anderson, Frederick Graybeal
First comprehensive list of non-native species established in three major regions of the United States First comprehensive list of non-native species established in three major regions of the United States
Invasive species are a subset of non-native (or alien) species, and knowing what species are non-native to a region is a first step to managing invasive species. People have been compiling non-native and invasive species lists ever since these species started causing harm, yet national non-native species lists are neither universal, nor common. Non-native species lists serve diverse...
Authors
Annie Simpson, Meghan C. Eyler
Revised groundwater-flow model of the glacial aquifer system north of Aberdeen, South Dakota, through water year 2015 Revised groundwater-flow model of the glacial aquifer system north of Aberdeen, South Dakota, through water year 2015
The city of Aberdeen, in northeastern South Dakota, requires an expanded and sustainable supply of water to meet current and future demands. Conceptual and numerical models of the glacial aquifer system in the area north of Aberdeen were developed by the U.S. Geological Survey in cooperation with the City of Aberdeen in 2012. The U.S. Geological Survey, in cooperation with the City of...
Authors
Joshua F. Valder, William G. Eldridge, Kyle W. Davis, Colton J. Medler, Karl R. Koth
Assessment of coalbed gas resources in the Kutei and Barito Basin Provinces, Indonesia, 2018 Assessment of coalbed gas resources in the Kutei and Barito Basin Provinces, Indonesia, 2018
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 10.7 trillion cubic feet of potential coalbed gas resources in the Kutei and Barito Basin Provinces of Indonesia.
Authors
Christopher J. Schenk, Tracey J. Mercier, Phuong A. Le, Marilyn E. Tennyson, Thomas M. Finn, Michael E. Brownfield, Kristen R. Marra, Stephanie B. Gaswirth, Heidi M. Leathers-Miller, Janet K. Pitman, Ronald M. Drake
Monitoring wadeable stream habitat conditions in Southeast Coast Network parks: Protocol narrative Monitoring wadeable stream habitat conditions in Southeast Coast Network parks: Protocol narrative
The Southeast Coast Network (SECN) has initiated a monitoring effort to assess habitat conditions in wadeable streams at national parks, recreation areas, battlefields, and monuments in Alabama, Georgia, and South Carolina. This monitoring effort includes Chattahoochee River National Recreation Area, Kennesaw Mountain National Battlefield Park, Congaree National Park, Horseshoe Bend...
Authors
Jacob M. McDonald, Mark B. Gregory, Jeffrey W. Riley, Eric N. Starkey
Increasing soil organic carbon to mitigate greenhouse gases and increase climate resiliency for California Increasing soil organic carbon to mitigate greenhouse gases and increase climate resiliency for California
Rising air temperatures are projected to continue to drive up urban, agricultural, and rangeland water use, straining both surface and groundwater resources. Scientific studies have shown that managing farms, ranches, and public lands to increase soil carbon can increase soil waterholding capacity and increase hydrologic benefits such as increased baseflows and aquifer recharge, reduced...
Authors
Lorraine E. Flint, Alan L. Flint, Michelle A. Stern, Allegra Mayer, Whendee L. Silver, Clyde Casey, Fabiano Franco, Kristin B. Byrd, Benjamin M. Sleeter, P. Alvarez, J. Creque, T. Estrada, D. Cameron
Concentrations of lead and other inorganic constituents in samples of raw intake and treated drinking water from the municipal water filtration plant and residential tapwater in Chicago, Illinois, and East Chicago, Indiana, July–December 2017 Concentrations of lead and other inorganic constituents in samples of raw intake and treated drinking water from the municipal water filtration plant and residential tapwater in Chicago, Illinois, and East Chicago, Indiana, July–December 2017
The U.S. Geological Survey (USGS) Environmental Health Mission Area (EHMA) is providing comprehensive science on sources, movement, and transformation of contaminants and pathogens in watershed and aquifer drinking-water supplies and in built water and wastewater infrastructure (referred to as the USGS Water and Wastewater Infrastructure project) in the Greater Chicago Area and elsewhere...
Authors
Kristin M. Romanok, Dana W. Kolpin, Shannon M. Meppelink, Michael J. Focazio, Maria Argos, Mary E. Hollingsworth, R. Blaine McCleskey, Andrea R. Putz, Alan Stark, Christopher P. Weis, Abderrahman Zehraoui, Paul M. Bradley
Methods used for the collection and analysis of chemical and biological data for the Tapwater Exposure Study, United States, 2016–17 Methods used for the collection and analysis of chemical and biological data for the Tapwater Exposure Study, United States, 2016–17
In 2016, the U.S. Geological Survey (USGS) Environmental Health Mission Area, initiated the Tapwater Exposure Study as part of an infrastructure project to assess human exposure to potential threats from complex mixtures of contaminants. In the pilot phase (2016), samples were collected from 11 States throughout the United States, and in the second phase (2017), the study focused on the...
Authors
Kristin M. Romanok, Dana W. Kolpin, Shannon M. Meppelink, Maria Argos, Juliane B. Brown, Michael J. Devito, Julie E. Dietze, Carrie E. Givens, James L. Gray, Christopher P. Higgins, Michelle L. Hladik, Luke R. Iwanowicz, Keith A. Loftin, R. Blaine McCleskey, Carrie A. McDonough, Michael T. Meyer, Mark J. Strynar, Christopher P. Weis, Vickie S. Wilson, Paul M. Bradley
Sierra Nevada summary report. California’s Fourth Climate Change Assessment Sierra Nevada summary report. California’s Fourth Climate Change Assessment
The Sierra Nevada region is critical to the environment and economy of California. Its places and peoples provide essential natural resources including fresh water, clean power, working lands, and famous wilderness. The region encompasses tremendous geographical, climatological, and ecological diversity that spans majestic mountains to deep desert basins. The climate consists of cool...
Authors
Michael D. Dettinger, Holly Alpert, John J. Battles, Jonathan Kusel, Hugh Safford, Dorian Fougeres, Clarke Knight, Lauren Miller, Sarah Sawyer
Are changes in lower trophic levels limiting prey-fish biomass and production in Lake Michigan? Are changes in lower trophic levels limiting prey-fish biomass and production in Lake Michigan?
To improve understanding of how recent changes in lower trophic levels in Lake Michigan could be affecting prey-fish biomass and production, the Lake Michigan Committee (LMC) convened a Lower Trophic Level Task Group and provided several charges that are responded to in this report. First, we compiled a comprehensive summary of lower trophiclevel data in Lake Michigan, separating out...
Authors
David B. Bunnell, Hunter J. Carrick, Charles P. Madenjian, Edward S. Rutherford, Henry A. Vanderploeg, Richard P. Barbiero, Elizabeth Hinchey-Malloy, Steven A. Pothoven, Catherine M. Riseng, Randall M. Claramunt, Harvey A. Bootsma, Ashley Elgin, Mark D. Rowe, Sara Thomas, Benjamin A. Turschak, Sergiusz J. Czesny, Kevin Pangle, David M. Warner
Method comparisons for determining concentrations of metals in water samples used in studies of fish migratory histories Method comparisons for determining concentrations of metals in water samples used in studies of fish migratory histories
Signatures developed from metal concentrations in water and fish bony structures can be used to demonstrate migration of individual fish between connected water bodies. The U.S. Geological Survey (USGS), in cooperation with the National Park Service and the Missouri Department of Conservation, compared two protocols for collecting and analyzing water samples for concentrations of several...
Authors
Jeffrey R. Ziegeweid, Steven J. Zigler, Ryan P. Maki, Byron N. Karns, Seth A. Love
Characterizing variability in vertical profiles of streamwise velocity and implications for streamgaging practices in the Chicago Sanitary and Ship Canal near Lemont, Illinois, January 2014 to July 2017 Characterizing variability in vertical profiles of streamwise velocity and implications for streamgaging practices in the Chicago Sanitary and Ship Canal near Lemont, Illinois, January 2014 to July 2017
A critical component of the Lake Michigan Diversion Accounting program, which oversees the diversion of Great Lakes water by the State of Illinois, is the U.S. Geological Survey streamgage on the Chicago Sanitary and Ship Canal near Lemont, Illinois. The long-term application of an up-looking acoustic Doppler current profiler at this streamgage allows the flows at this study site to be...
Authors
P. Ryan Jackson