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The U.S. Geological Survey's 1998 assessment of the 1002 Area of the Arctic National Wildlife Refuge significantly revised previous estimates of the area's petroleum supply potential. The mean (or expected) value of technically recoverable undiscovered oil for the Study Area (Federal 1002 Area, adjacent State waters, and Native Lands)...

As part of the requirements for the Geographic Research and Applications Prospectus grants, this Open-File Report is the second of two that resulted from the first year of the project. The first Open-File Report (OFR 01-418) introduced the project, reviewed the existing body of literature, and outlined the research approach....

This report, a product of the National Water- Quality Assessment Program, is a compilation of physical data and biological data for algae, aquatic invertebrates, and fish collected in the Carson and Truckee River Basins, Nevada and California. Most of the data were collected between 1993 and 1996 at selected reaches on the Carson and Truckee Rivers. Algae...

Water-quality measurements and benthic algal samples were measured or collected from select Minnesota streams as part of a multiagency (Minnesota Pollution Control Agency, Minnesota Department of Natural Resources, U.S. Environmental Protection Agency, and U.S. Geological Survey) study. The goal of the multiagency study was to identify quantifiable thresholds of water-quality...

Because regional-scale atmospheric deposition data in the Rocky Mountains are sparse, a program was designed by the U.S. Geological Survey to more thoroughly determine the quality of precipitation and to identify sources of atmospherically deposited pollution in a network of high-elevation sites. Depth-integrated samples of seasonal snowpacks at 52 sampling...

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This report presents the results of the U.S. Geological Survey's analytical evaluation program for six standard reference samples -- T-167 (trace constituents), M-160 (major constituents), N-71 (nutrient constituents), N-72 (nutrient constituents), P-37 (low ionic-strength constituents), and Hg-33 (mercury) -- that were distributed in September 2001 to laboratories enrolled in the U.S. Geological Survey sponsored...

Magnetotelluric data collected along five profiles show deep resistivity structures beneath the Battle Mountain-Eureka and Carlin gold trends in north-central Nevada, which appear consistent with tectonic breaks in the crust that possibly served as channels for hydrothermal fluids. It seems likely that gold deposits along these linear trends were, therefore, controlled by deep regional crustal fault...

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This report presents a map showing the potentiometric surface of the Lower Patapsco aquifer in the Patapsco Formation of Cretaceous age in Southern Maryland during September 2001. The map is based on water-level measurements in 65 wells. The potentiometric surface was as high as 110 feet above sea level near...

This report presents water-quality data that have been compiled and collected for a reconnaissance-level assessment of water quality near Flandreau, South Dakota. The investigation was initiated as a cooperative effort between the U.S. Geological Survey and the Flandreau Santee Sioux Tribe. Members of the Flandreau Santee Sioux Tribe have expressed concern...

Modeling regional and global activities of climatic and human-induced change requires accurate geographic data from which we can develop mathematical and statistical tabulations of attributes and properties of the environment. Many of these models depend on data formatted as raster cells or matrices of pixel values. Recently, it has been...

In this report, we present preliminary data on surface and pore water geochemistry from 22 sites in south Florida sampled during 1994 and 1995. These results are part of a larger study designed to evaluate the role of biogeochemical processes in sediments in the cycling of carbon, nitrogen, phosphorus, and...

The U.S. Geological Survey (USGS), U.S. Department of the Interior, is the Nation's largest Earth-science information agency. Among its many responsibilities, such as map making and providing information on earthquakes and other natural hazards, the USGS provides information on the Nation's water resources. The USGS has collected and analyzed hydrologic...

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After the devastating floods caused by Hurricane Mitch in 1998, maps of the areas and depths of the 50-year-flood inundation at 15 municipalities in Honduras were prepared as a tool for agencies involved in reconstruction and planning. This report, which is one in a series of 15, presents maps of...

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Satellite imagery from the Landsat Thematic Mapper (nominal date 1992) was used to classify and map the location of irrigated land overlying the High Plains aquifer. The High Plains aquifer underlies 174,000 square miles in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. The U.S....

MFI2K is a data-input (entry) program for the U.S. Geological Survey modular three-dimensional finite-difference ground-water model, MODFLOW-2000. MFI2K runs on personal computers. MFI2K supports the solute transport and parameter-estimation capabilities that are incorporated in MODFLOW-2000. Data for MODPATH, a particle-tracking program for use with MODFLOW-2000, also can be entered using...

Executive Summary  The Northwest Dade County Freshwater Lake Plan Area (commonly referred to as the Lake Belt Area) is vital to the future planning and development of southeastern Florida. This area is located within one of the most environmentally sensitive parts of the state – the eastern borders of the...

SutraPrep facilitates the creation of three-dimensional (3D) input datasets for the USGS ground-water flow and transport model SUTRA Version 2D3D.1. It is most useful for applications in which the geometry of the 3D model domain and the spatial distribution of physical properties and boundary conditions is relatively simple. SutraPrep can...

This report presents a map showing the change in the potentiometric surface of the Magothy aquifer in the Magothy Formation of Cretaceous age in Southern Maryland for September 1975 and September 2001. The map, based on water level measurements in 54 wells, shows that during the 26-year period, the potentiometric...