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Approximately 10 percent of the world’s active volcanoes are located in the Alaskan Aleutian arc and produce about 3-4 explosive eruptions per year. Even with this high amount of volcanic activity, the remote locations and harsh environments of the Aleutian volcanoes conspire to keep them among some of the most...

The U.S. Geological Survey (USGS), in cooperation with the Tennessee Department of Environment and Conservation, Division of Superfund, collected discharge, rainfall, continuous water-quality (temperature, dissolved oxygen, specific conductance, and pH), and volatile organic compound (VOC) data from three karst springs in Middle Tennessee from February 2000 to May 2001. Continuous...

A method for the isolation of 20 parent organophosphate pesticides and 5 organophosphate pesticide degradates from natural-water samples is described. Compounds are extracted from water samples with methylene chloride using a continuous liquid-liquid extractor for 6 hours. The solvent is evaporated using heat and a flow of nitrogen to a...

A preliminary assessment of the microbial communities and biodegradation processes for chlorinated volatile organic compounds was con-ducted by the U.S. Geological Survey in wetlands at the Cluster 13, Lauderick Creek area at Aberdeen Proving Ground, Maryland. The U.S. Geological Survey collected wetland sediment samples from 11 sites in the Lauderick...

The Navajo Nation and the Hopi Tribe in the Black Mesa area depend on ground water from sandstones of the N aquifer for domestic, agricultural, municipal, and industrial needs. They are concerned that pumping of water from the N aquifer will induce leakage from the overlying D aquifer, resulting in...

Excessive nutrients and sediment are among the most significant environmental stressors in the Delaware Inland Bays (Rehoboth, Indian River, and Little Assawoman Bays). Sources of nutrients, sediment, and other contaminants within the Inland Bays watershed include point-source discharges from industries and wastewater-treatment plants, runoff and infiltration to ground water from...

Alkaline persulfate digestion was evaluated and validated as a more sensitive, accurate, and less toxic alternative to Kjeldahl digestion for routine determination of nitrogen and phosphorus in surface- and ground-water samples in a large-scale and geographically diverse study conducted by U.S. Geological Survey (USGS) between October 1, 2001, and September...

Bed elevations were measured at 131 monumented cross sections in the Colorado River between Glen Canyon Dam and Lava Falls Rapid from June 1992 to September 1999 to provide data on channel sand storage. This report documents the location of the 131 monumented cross sections, dates of measurements for all...

The Christina River Basin drains 565 square miles (mi2) in Pennsylvania and Delaware and includes the major subbasins of Red Clay Creek, White Clay Creek, Brandywine Creek, and Christina River. The Red Clay Creek is the smallest of the subbasins and drains an area of 54 mi2. Streams in the...

Diffusion samplers and temporary drive points were used to test for ordnance-related compounds in ground water discharging to Snake Pond near Camp Edwards at the Massachusetts Military Reservation, Cape Cod, MA. The contamination resulted from artillery use and weapons testing at various ranges upgradient of the pond.The diffusion samplers were...

This report presents the results of the U.S. Geological Survey's analytical evaluation program for six standard reference samples -- T-163 (trace constituents), M-156 (major constituents), N-67 (nutrient constituents), N-68 (nutrient constituents), P-35 (low ionic strength constituents), and Hg-31 (mercury) -- that were distributed in October 2000 to 126 laboratories enrolled...

The environmental controls on water quality were the focus of our study in a portion of the Battle Mountain mining district, north-central Nevada. Samples representing areas outside known mineralized areas, in undisturbed mineralized areas, and in mined areas were chemically and isotopically analyzed. The results are related to geologic, hydrologic, and climatic data. Streams in background areas...

The geologic map of the Mount Trumbull 30' x 60' quadrangle is a cooperative product of the U.S. Geological Survey, the National Park Service, and the Bureau of Land Management that provides geologic map coverage and regional geologic information for visitor services and resource management of Grand Canyon National Park,...

Changes in the area and volume of polar ice sheets are intricately linked to changes in global climate, and the resulting changes in sea level may severely impact the densely populated coastal regions on Earth. Melting of the West Antarctic part alone of the Antarctic ice sheet could cause a...

InSAR is a powerful technique that uses radar data acquired at different times to measure land-surface deformation, or displacement, over large areas at a high level of spatial detail and a high degree of measurement resolution. InSAR displacement maps (interferograms), in conjunction with other hydrogeologic data, have been used to...

We have studied the effects of local topography and canopy structure on turbulent flux measurements at a site located in mountainous terrain within a subalpine, coniferous forest. Our primary aim was to determine whether the complex terrain of the site affects the accuracy of eddy flux measurements from a practical...

A total of 32 test holes were drilled in well-field areas of Hillsborough, Pasco, and Pinellas Counties in the early 1970's to collect information on the hydraulic and geologic properties of shallow formations overlying the Upper Floridan aquifer. Lithologic profiles were compiled and geohydrologic units identified for each test hole....

This aeromagnetic map covers the southern portion of San Francisco Bay, the Santa Clara Valley and surrounding mountains, part of which has been modelled in threedimensions (Jachens and other, 2001). The magnetic anomaly map has been compiled from existing digital data. Data was obtained from six aeromagnetic surveys that were...

A method was developed to construct stage-discharge rating curves for the Colorado River in Grand Canyon, Arizona, using two stage-discharge pairs and a stage-normalized rating curve. Stage-discharge rating curves formulated with the stage-normalized curve method are compared to (1) stage-discharge rating curves for six temporary stage gages and two streamflow-gaging...

This report gives estimates of, and presents techniques for estimating, the magnitude of peak flows for streams in Kentucky for recurrence intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years. A flowchart in this report guides the user to the appropriate estimates and (or) estimating techniques for...

This geologic database of the Redlands 7.5' quadrangle was prepared by the Southern California Areal Mapping Project (SCAMP), a regional geologic-mapping project sponsored jointly by the U.S. Geological Survey and the California Geological Survey. The database was developed as a contribution to the National Cooperative Geologic Mapping Program's National Geologic...

From November 2001 to January 2002, a study of the ground-water resources in the Crumpton Creek area of Middle Tennessee was conducted to determine whether volatile organic compounds (VOCs) from Arnold Air Force Base (AAFB) have affected local private water supplies and to advance understanding of the ground-water-flow system in...

A project to study ground-water and surface-water interactions in the desert southwestern United States was initiated in 2001 by the Tucson, Arizona office of the Water Resources Division, U.S. Geological Survey (USGS). One of the goals of the Southwest Ground-water Resources Project was to develop a regional synthesis that includes...

The purpose of this report is to release texture and carbonate content analyses of 107 seafloor sediments collected within and near the East and West Flower Garden Banks areas of the Sanctuary and to show relationships between these data and existing bathymetric data. The sediment data, in conjunction with previously...

An experimental water release from the Glen Canyon Dam into the Colorado River above Grand Canyon was conducted in September 2000 by the U.S. Bureau of Reclamation. The U.S. Geological Survey (USGS) conducted sidescan sonar surveys between Glen Canyon Dam (mile -15) and Diamond Creek (mile 220), Arizona (mile designations...