Publications

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

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

Hurricane Andrew produced changes to the Louisiana wetlands not normally observed after lesser, more common storms. For example, the <25 m/s wind speeds generated by cold fronts and winter storms, and any accompanying storm surge, do not cause substantial, wide-spread alteration of marsh vegetation. During Hurricane Andrew, however, the wind, the wind-driven storm surge, or both produced severe, w

On August 26, 1992, Hurricane Andrew hit the Louisiana coast and traversed a large portion of the lower Atchafalaya Basin, bounding the largest remaining tract of cypress-tupelo and bottomland hardwood swamp in the United States. Permanent field sites were established following the hurricane to assess the extent of forest damage and to monitor the rate and process of forest recovery. Bottomland ha

We evaluated the utility of four nondestructive condition indices—body mass, body mass scaled by wing chord length, fat scoring, and total body electrical conductivity method (TOBEC)—as predictors of lipid levels in migrating Wood Thrushes (Hylocichla mustelina), Swainson's Thrushes (Catharus ustulatus), and Summer Tanagers (Piranga rubra). The Red-winged Blackbird (Agelaius phoeniceus), a winter

This study was undertaken to evaluate the relationship between mammalian and piscine 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) toxic equivalency factors (TEFs) for PCBs, based on induction of CYP1A enzyme activity, catalytic protein, and mRNA. Rainbow trout administered a single i.p. injection of TCDD had an average (±SD) ED50 of 0.91 ± 0.14 μg TCDD/kg for induction of ethoxyresorufin O-deethylas

Rainfall in southeast Texas, which ranged in amounts from about 8 to more than 28 inches during October 15–19, 1994, caused severe flooding in parts of a 38-county area. A combination of meteorological events—residual atmospheric moisture over southern Texas associated with Hurricane Rosa from the Pacific Coast of Mexico and low-level moisture from the Gulf of Mexico drawn inland to a warm front b

The Trinity River Basin National Water Quality Assessment (NAWQA) study-unit staff began assessment activities in 1991, and in 1992, undertook a retrospective review of existing data on pesticides. The main purpose of this review was to aid in the design of a pesticide-sampling network for the study unit. The review consisted of the compilation, screening, and analysis of available pesticide-sampl

Previous maximum flows on many streams and rivers were exceeded during the flood of 1993 in the upper Mississippi River Basin. Not only were peak discharges exceeded at many streamflow-gaging stations, but flood volumes were significantly higher than previous maximums. Rainfall amounts that were greater than 50 inches were recorded in parts of Kansas, Missouri, and Iowa from April 1 through Septem

Assessment activities in the Trinity River Basin study unit of the National Water-Quality Assessment (NAWQA) Program began in October 1991 with 2 years dedicated to planning, analyzing existing information, and designing data-collection networks. In October 1993, a 3-year intensive data-collection program was initiated. Guidelines were provided by the NAWQA Program National Synthesis team, and sug

Carp (Cyprinus carpio) collected from Saginaw Bay, Michigan, containing 8.4 mg total polychlorinated biphenyls (PCBs)/kg and 194 ng of 2,3,7,8-tetrachloro-dibenzo-p-dioxin equivalents (TEQs)/kg, were substituted for marine fish at levels of 0, 10, 20, or 40% in the diets of adult ranch mink (Mustela vison). The diets, containing 0.015, 0.72, 1.53, and 2.56 mg PCBs/kg diet, or 1.03, 19.41, 40.02, a