Publications

No abstract available.

Two electromagnetic surface geophysical techniques were used to explore the ground-water resources of Isla de Mona, Puerto Rico—a 55-square-kilometer island located between Puerto Rico and Hispañiola, Isla de Mona is a tectonically uplifted carbonate plateau of Neogene age that has an average elevation of about 50 meters above mean sea level. This plateau is bounded by vertical cliffs except on th

We present a simple method for estimation of long-term mean denudation rates using in situ-produced cosmogenic 10Be in fluvial sediments. Procedures are discussed to account for the effects of soil bioturbation, mass wasting and attenuation of cosmic rays by biomass and by local topography. Our analyses of 10Be in quartz from bedrock outcrops, soils, mass-wasting sites and riverine sediment from t

Long Valley caldera in east central California has been the site of crustal unrest in the form of seismicity and ground deformation in response to magmatic inflation since 1980. Uplift of the resurgent dome has totaled ∼0.6 m over the 1975–1992 period. Within this region of uplift, and near the southwestern edge of the resurgent dome, is the Casa Diablo area, which experienced relative subsidence

Western mosquitofish Gambusia affinis from the San Luis Drain (SLD), a major conveyance system for seleniferous agricultural subsurface (tile) drainage water in the San Joaquin Valley, California, experienced lower reproductive success than did mosquitofish from a nearby reference area (Pond 26 at the Volta Wildlife Area, VOLTA) that had no history of receiving tile drainage. At birth, mean surviv

The Grand Portage Indian Reservation Tribal Council needs information about the availability and quality of the ground water in the Reservation to develop, protect, and manage this resource for future use. The U.S. Geological Survey, in cooperation with the Grand Portage Indian Reservation Tribal Council, did a three-year study of the ground water in the Reservation to provide this needed informat

The U.S. Geological Survey, in cooperation with the Bent County Board of County Commissioners, began a study to evaluate irrigation water use quanti- tatively for about 91,630 acres of farmland irrigated from the 103.7-mile-long Fort Lyon Main Canal in the Arkansas River Valley of southeastern Colorado. This report provides information from 1980 and 1990 for four hydrologic components of irrigatio

The environmental and hydrologic setting of the Ozark Plateaus National Water-Quality Assessment (NAWQA) study unit and the factors that affect water quality are described in this report. The primary natural and cultural features that affect water- quality characteristics and the potential for future water-quality problems are described. These environmental features include climate, physio- graphy

No abstract available.

The mission of the U.S. Geological Survey, Water Resources Division, is to provide the hydrologic information and understanding needed for the optimum utilization and management of the Nation's water resources for the overall benefit of the people of the United States. This report describes water-resources activities of the Water Resources Division in North Dakota in fiscal year 1994. Information

Suspended-sediment transport and its relation to water quality are important issues in the South Platte River Basin. Most sediment enters the South Platte River during snowmelt runoff from March to June. The suspended sediment varies by particle size, concentration, and load. Suspended-sediment data in the South Platte River for water years 1980-92 are limited; therefore, only generalizations can

Selected meteorological data were collected at a study site adjacent to a low-level radioactive-waste burial facility near Beatty, Nevada, for calendar years 1990 and 1991. Data were collected in support of ongoing studies to estimate the potential for downward movement of radionuclides into the unsaturated sediments beneath waste-burial trenches at the facility. The data include air temperature,