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.
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Long Valley Caldera Lake and reincision of Owens River Gorge Long Valley Caldera Lake and reincision of Owens River Gorge
Owens River Gorge, today rimmed exclusively in 767-ka Bishop Tuff, was first cut during the Neogene through a ridge of Triassic granodiorite to a depth as great as its present-day floor and was then filled to its rim by a small basaltic shield at 3.3 Ma. The gorge-filling basalt, 200 m thick, blocked a 5-km-long reach of the upper gorge, diverting the Owens River southward around the...
Authors
Wes Hildreth, Judy Fierstein
Mechanisms of aquatic species invasions across the South Atlantic Landscape Conservation Cooperative region Mechanisms of aquatic species invasions across the South Atlantic Landscape Conservation Cooperative region
Invasive species are a global issue, and the southeastern United States is not immune to the problems they present. Therefore, various analyses using modeling and exploratory statistics were performed on the U.S. Geological Survey Nonindigenous Aquatic Species (NAS) Database with the primary objective of determining the most appropriate use of presence-only data as related to invasive...
Authors
Amy J. Benson, Bradley Stith, Victor C. Engel
Estimated nitrogen and phosphorus inputs to the Fish Creek watershed, Teton County, Wyoming, 2009–15 Estimated nitrogen and phosphorus inputs to the Fish Creek watershed, Teton County, Wyoming, 2009–15
Nutrients, such as nitrogen and phosphorus, are essential for plant and animal growth and nourishment, but the overabundance of bioavailable nitrogen and phosphorus in water can cause adverse health and ecological effects. It is generally accepted that increased primary production of surface-water bodies because of high inputs of nutrients is now the most important polluting effect in...
Authors
Cheryl A. Eddy-Miller, Roy Sando, Michael J. MacDonald, Carlin Girard
Four-band image mosaic of the Colorado River corridor downstream of Glen Canyon Dam in Arizona, derived from the May 2013 airborne image acquisition Four-band image mosaic of the Colorado River corridor downstream of Glen Canyon Dam in Arizona, derived from the May 2013 airborne image acquisition
In May 2013, the U.S. Geological Survey’s Grand Canyon Monitoring and Research Center acquired airborne multispectral high-resolution data for the Colorado River in the Grand Canyon, Arizona. The image data, which consist of four color bands (blue, green, red, and near-infrared) with a ground resolution of 20 centimeters, are available to the public as 16-bit geotiff files at http://dx...
Authors
Laura E. Durning, Joel B. Sankey, Philip A. Davis, Temuulen T. Sankey
Occurrence, distribution, and volume of metals-contaminated sediment of selected streams draining the Tri-State Mining District, Missouri, Oklahoma, and Kansas, 2011–12 Occurrence, distribution, and volume of metals-contaminated sediment of selected streams draining the Tri-State Mining District, Missouri, Oklahoma, and Kansas, 2011–12
Lead and zinc were mined in the Tri-State Mining District (TSMD) of southwest Missouri, northeast Oklahoma, and southeast Kansas for more than 100 years. The effects of mining on the landscape are still evident, nearly 50 years after the last mine ceased operation. The legacies of mining are the mine waste and discharge of groundwater from underground mines. The mine-waste piles and...
Authors
D. Charlie Smith
Building unified geospatial data for land-change modeling—A case study in the area of Richmond, Virginia Building unified geospatial data for land-change modeling—A case study in the area of Richmond, Virginia
An effort to build a unified collection of geospatial data for use in land-change modeling (LCM) led to new insights into the requirements and challenges of building an LCM data infrastructure. A case study of data compilation and unification for the Richmond, Va., Metropolitan Statistical Area (MSA) delineated the problems of combining and unifying heterogeneous data from many...
Authors
David I. Donato, Jason L. Shapiro
Collection, processing, and quality assurance of time-series electromagnetic-induction log datasets, 1995–2016, south Florida Collection, processing, and quality assurance of time-series electromagnetic-induction log datasets, 1995–2016, south Florida
Time-series electromagnetic-induction log (TSEMIL) datasets are collected from polyvinyl-chloride cased or uncased monitoring wells to evaluate changes in water conductivity over time. TSEMIL datasets consist of a series of individual electromagnetic-induction logs, generally collected at a frequency of once per month or once per year that have been compiled into a dataset by eliminating...
Authors
Scott T. Prinos, Robert Valderrama
Groundwater-flow model of the northern High Plains aquifer in Colorado, Kansas, Nebraska, South Dakota, and Wyoming Groundwater-flow model of the northern High Plains aquifer in Colorado, Kansas, Nebraska, South Dakota, and Wyoming
The High Plains aquifer is a nationally important water resource underlying about 175,000 square miles in parts of eight states: Colorado, Kansas, Oklahoma, Nebraska, New Mexico, South Dakota, Texas, and Wyoming. Droughts across much of the Northern High Plains from 2001 to 2007 have combined with recent (2004) legislative mandates to elevate concerns regarding future availability of...
Authors
Steven M. Peterson, Amanda T. Flynn, Jonathan P. Traylor
Estimating natural monthly streamflows in California and the likelihood of anthropogenic modification Estimating natural monthly streamflows in California and the likelihood of anthropogenic modification
Because natural patterns of streamflow are a fundamental property of the health of streams, there is a critical need to quantify the degree to which human activities have modified natural streamflows. A requirement for assessing streamflow modification in a given stream is a reliable estimate of flows expected in the absence of human influences. Although there are many techniques to...
Authors
Daren M. Carlisle, David M. Wolock, Jeanette K. Howard, Theodore E. Grantham, Kurt Fesenmyer, Michael Wieczorek
Flow characteristics and salinity patterns of tidal rivers within the northern Ten Thousand Islands, southwest Florida, water years 2007–14 Flow characteristics and salinity patterns of tidal rivers within the northern Ten Thousand Islands, southwest Florida, water years 2007–14
Freshwater flow to the Ten Thousand Islands estuary has been altered by the construction of the Tamiami Trail and the Southern Golden Gate Estates. The Picayune Strand Restoration Project, which is associated with the Comprehensive Everglades Restoration Plan, has been implemented to improve freshwater delivery to the Ten Thousand Islands estuary by removing hundreds of miles of roads...
Authors
Amanda Booth, Lars E. Soderqvist
Assessment of coalbed gas resources of the Central and South Sumatra Basin Provinces, Indonesia, 2016 Assessment of coalbed gas resources of the Central and South Sumatra Basin Provinces, Indonesia, 2016
Using a geology-based assessment methodology, the U.S. Geological Survey estimated a mean of 20 trillion cubic feet of undiscovered, technically recoverable coalbed gas resource in the Central and South Sumatra Basin Provinces of Indonesia.
Authors
Christopher J. Schenk, Timothy R. Klett, Marilyn E. Tennyson, Tracey J. Mercier, Michael E. Brownfield, Janet K. Pitman, Stephanie B. Gaswirth, Thomas M. Finn
Assessment of continuous oil and gas resources of the South Sumatra Basin Province, Indonesia, 2016 Assessment of continuous oil and gas resources of the South Sumatra Basin Province, Indonesia, 2016
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 689 million barrels of continuous shale oil and 3.9 trillion cubic feet of shale gas in the South Sumatra Basin Province in Indonesia.
Authors
Christopher J. Schenk, Marilyn E. Tennyson, Timothy R. Klett, Thomas M. Finn, Tracey J. Mercier, Stephanie B. Gaswirth, Kristen R. Marra, Phuong A. Le, Sarah J. Hawkins