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These publications showcase the significant science conducted in our Science Centers.

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Morphology and stratal geometry of the Antarctic continental shelf: Insights from models Morphology and stratal geometry of the Antarctic continental shelf: Insights from models

Reconstruction of past ice-sheet fluctuations from the stratigraphy of glaciated continental shelves requires understanding of the relationships among the stratal geometry, glacial and marine sedimentary processes, and ice dynamics. We investigate the formation of the morphology and the broad stratal geometry of topsets on the Antarctic continental shelf with numerical models. Our models...
Authors
Alan K. Cooper, Peter F. Barker, Giuliano Brancolini

New approaches to the analysis of population trends in land birds: Comment New approaches to the analysis of population trends in land birds: Comment

James et al. (1996, Ecology 77:13-27) used data from the North American Breeding Bird Survey (BBS) to examine geographic variability in patterns of population change for 26 species of wood warblers. They emphasized the importance of evaluating nonlinear patterns of change in bird populations, proposed LOESS-based non-parametric and semi-parametric analyses of BBS data, and contrasted...
Authors
William A. Link, John R. Sauer

Surface-water quality changes after 5 years of nutrient management in the Little Conestoga Creek headwaters, Pennsylvania, 1989-91 Surface-water quality changes after 5 years of nutrient management in the Little Conestoga Creek headwaters, Pennsylvania, 1989-91

A 5.82-square-mile drainage basin in the headwaters of the Little Conestoga Creek in Lancaster County, Pa., was investigated from October 1989 through September 1991 as part of a longer-term effort to determine the effects of nutrient management on surface-water quality. A previous investigation found no statistical evidence that implementation of nutrient management from 1986 to 1989...
Authors
Edward H. Koerkle, Linda C. Gustafson-Minnich, Michael D. Bilger

Scour at bridges, what's it all about? Stream stability and scour-assessment at bridges in Pennsylvania Scour at bridges, what's it all about? Stream stability and scour-assessment at bridges in Pennsylvania

Scour is the removal of sediment (soil and rocks) from streambeds and streambanks caused by movingwater. Although scour may occur at any time, it is usually more significant during high flows, when the water is swift and deep. Swiftly movingwater has more energy (turbulence and velocity) to lift and transport sediment than slowly moving water.
Authors
M. V. Truhlar, P. A. Telis

Evaluation of selected wells in Pennsylvania's observation-well program as of 1993 Evaluation of selected wells in Pennsylvania's observation-well program as of 1993

In 1993, the U.S. Geological Survey operated 62 observation wells in 60 of Pennsylvania's 67 counties in cooperation with the Pennsylvania Department of Environmental Resources. These wells attempt to monitor an aerial extent of 45,000 square miles and penetrate 39 geologic formations or water-bearing units of 14 physiographic provinces. Some wells were drilled specifically for the...
Authors
R.W. Conger

Hydrogeologic investigation of the Malvern TCE Superfund Site, Chester County, Pennsylvania Hydrogeologic investigation of the Malvern TCE Superfund Site, Chester County, Pennsylvania

The Malvern TCE Superfund Site, a former solvent recycling facility that now stores and sells solvents, consists of a plant and disposal area, which are approximately 1,900 ft (feet) apart. The site is underlain by an unconfined carbonate bedrock aquifer in which permeability has been enhanced in places by solution. Water levels respond quickly to precipitation and show a similar...
Authors
Ronald A. Sloto

Modeling waves and circulation in Lake Pontchartrain, Louisiana Modeling waves and circulation in Lake Pontchartrain, Louisiana

The U.S. Geological Survey is conducting a study of storm-driven sediment resuspension and transport in Lake Pontchartrain, Louisiana. Two critical processes related to sediment transport in the lake are (1) the resuspension of sediments due to wind-generated storm waves and (2) the movement of resuspended material by lake currents during storm wind events. The potential for sediment...
Authors
Richard P. Signell, Jeffrey H. List
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