Conference Papers
Science Quality and Integrity
The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
Browse almost 5,000 conference papers authored by our scientists and refine search by topic, location, year, and advanced search.
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Time-series monitoring in fractured-rock aquifers
Time-lapse monitoring of subsurface processes is an emerging and promising area of hydrogeophysics. The combined use of non-invasive or minimally invasive geophysical methods with hydraulic and geochemical sampling is a cost-effective approach for aquifer characterization, long-term aquifer monitoring, and remediation monitoring. Time-lapse geophysical surveys can indirectly measure time-varying h
Authors
Carole D. Johnson, John W. Lane, Frederick D. Day-Lewis
U-Series isotopes as indicators of water/rock interaction in the unsaturated zone at Yucca Mountain, Nevada, USA
No abstract available.
Authors
James B. Paces, Leonid A. Neymark
High resolution climate of the past 3,500 years of coastal northernmost California
No abstract available.
Authors
John A. Barron, Linda E. Heusser, Clark Alexander
Diatoms as indicators of late Holocene freshwater flow variation in the San Francisco Bay estuary, central California, U.S.A
No abstract available.
Authors
Scott W. Starratt
Acidity and Alkalinity in mine drainage: Practical considerations
In this paper, we emphasize that the Standard Method hot peroxide treatment procedure for acidity determination (hot acidity) directly measures net acidity or net alkalinity, but that more than one water-quality measure can be useful as a measure of the severity of acid mine drainage. We demonstrate that the hot acidity is related to the pH, alkalinity, and dissolved concentrations of Fe, Mn, and
Authors
Charles A. Cravotta, III, Carl S. Kirby
Acidity and alkalinity in mine drainage: Theoretical considerations
Acidity, net acidity, and net alkalinity are widely used parameters for the characterization of mine drainage, but these terms are not well defined and are often misunderstood. Incorrect interpretation of acidity, alkalinity, and derivative terms can lead to inadequate treatment design or poor regulatory decisions. We briefly explain derivations of theoretical expressions of three types of alkalin
Authors
Carl S. Kirby, Charles A. Cravotta
Analysis of summer 2002 melt extent on the Greenland ice sheet using MODIS and SSM/I data
Previous work has shown that the summer of 2002 had the greatest area of snow melt extent on the Greenland ice sheet ever recorded using passive-microwave data. In this paper, we compare the 0deg isotherm derived from the Moderate-Resolution Imaging Spectroradiometer (MODIS) instrument, with Special Sensor Microwave/Imager (SSM/I)-derived melt, at the time of the maximum melt extent in 2002. To va
Authors
D. K. Hall, R.S. Williams, K. Steffen, Janet Y.L. Chien
Calibration strategies for a groundwater model in a highly dynamic alpine floodplain
Most surface flows to the 20-km-long Maggia Valley in Southern Switzerland are impounded and the valley is being investigated to determine environmental flow requirements. The aim of the investigation is the devel-opment of a modelling framework that simulates the dynamics of the ground-water, hydrologic, and ecologic systems. Because of the multi-scale nature of the modelling framework, large-sca
Authors
L. Foglia, P. Burlando, Mary C. Hill, S. Mehl
Natural bitumen and extra-heavy oil
Crude oil is found in sedimentary rocks throughout the world, except, thus far, in Antarctica. In many places the oil has been degraded, so that it is represented by viscous black oil that is difficult to recover, transport, and refine. Depending upon the degree of degradation the result is extra-heavy oil or, in the extreme case, natural bitumen. Except in Canada, precise quantitative reserves an
Authors
R. F. Meyer, Emil D. Attanasi
Traditional and new methods to derive sediment-discharge information in the United States
No abstract available.
Authors
John R. Gray, G. Douglas Glysson
Economic impacts of anthropogenic activities on coastlines of the United States
Anthropogenic activities primarily impact coasts by reducing sediment inputs, altering sediment transport processes, and accelerating sediment losses to the offshore. These activities include: sand and gravel extraction, navigation and shore protection works; non-structural shoreline management strategies such as beach nourishment, sand by-passing and beach scraping, dams and flood control works;
Authors
Orville T. Magoon, S. Jeffress Williams, Linda K. Lent, James A. Richmond, Donald D. Treadwell, Scott L. Douglass, Billy L. Edge, Lesley C. Ewing, Anthony P. Pratt
Effects of solar irradiance on reef coral physiology and recriutment
No abstract available.
Authors
Ilsa B. Kuffner