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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One perspective on spatial variability in geologic mapping
This paper discusses some of the differences between geologic mapping and soil mapping, and how the resultant maps are interpreted. The role of spatial variability in geologic mapping is addressed only indirectly because in geologic mapping there have been few attempts at quantification of spatial differences. This is largely because geologic maps deal with temporal as well as spatial variability
Authors
H. W. Markewich, S.C. Cooper
Origins of acid fluids in geothermal reservoirs
Acid fluids in geothermal reservoirs are rare. Their occurrence in geothermal systems associated with recent volcanism (Tatun, Sumikawa, Miravalles) probably indicates that the geothermal reservoir fluid was derived from volcanic fluid incompletely neutralized by reaction with feldspars and micas. Superheated steam containing HCl (Larderello, The Geysers) forms acid where it condenses or mixes wit
Authors
Alfred Truesdell
Overburden deformation and hydrologic changes due to longwall coal mine subsidence on the Illinois Basin
Subsidence-induced deformation and hydrologic changes were studied at two active longwall coal mines in Illinois using surveying and geotechnical monitoring. Surface subsidence characteristics fall into a range common to other Illinois longwall operations. Subsidence-induced water level fluctuations correlated with mining activity and the passing of the dynamic subsidence wave. Aquifer thickness a
Authors
J.T. Kelleher, D. J. Van Roosendaal, B.B. Mehnert, D.F. Brutcher, R.A. Bauer
Processes controlling the retreat of the Isles Dernieres, a Louisiana barrier-island chain
The Isles Dernieres is a low-lying, transgressive barrier-island chain situated about 150 km west of the modern Mississippi delta. Much of the Isles Dernieres consists of highly dissected salt-marsh muds that lie at or slightly above sea level and are covered by a veneer of sand along the shoreline facing the Gulf of Mexico. Maximum berm elevations are generally less than 1.5 m above mean sea leve
Authors
John R. Dingler, Thomas E. Reiss
Production of carbon molecular sieves from illinois coals. An assessment
Chars were produced from an Illinois No. 2 bituminous coal under various pyrolysis and activation conditions and tested for their molecular sieve properties. The amount of N2 compared to the amount of CO2 adsorbed by each char was used as a preliminary indicator of its molecular sieve properties. This relatively simple, but apparently useful test was confirmed by successfully characterizing the we
Authors
Anthony A. Lizzio, Massoud Rostam-Abadi
Proposed U.S. Geological Survey standard for digital orthophotos
The U.S. Geological Survey has added the new category of digital orthophotos to the National Digital Cartographic Data Base. This differentially rectified digital image product enables users to take advantage of the properties of current photoimagery as a source of geographic information. The product and accompanying standard were implemented in spring 1991. The digital orthophotos will be quadran
Authors
David Hooper, Vincent Caruso
Recent advances in halibut (Hippoglossus spp.) culture
No abstract available
Authors
R.R. Stickney, H. W. Liu, S.D. Smith
Rehabilitation of a Species: The Black-Footed Ferret (Mustela nigripes)
Black-footed ferrets (Mustela nigripes) are an endangered carnivore endemic to North America. This small nocturnal member of the weasel family is totally dependent on the prairie dog (Cynomys spp.) ecosystem for survival. The ferret lives in prairie dog burrows and relies on prairie dogs for 90 percent of its diet (3,21). Poisoning of prairie dogs was largely responsible for the 98 percent redu
Authors
Brian Miller, Dean E. Biggins, Lou Hanebury, Courtney Conway, Chris Wemmer
Relation between the national handbook of recommended methods for water data acquisition and ASTM standards
In the late 1950's, intense demands for water and growing concerns about declines in the quality of water generated the need for more water-resources data. About thirty Federal agencies, hundreds of State, county and local agencies, and many private organizations had been collecting water data. However, because of differences in procedures and equipment, many of the data bases were incompatible. I
Authors
G. Douglas Glysson, John V. Skinner
Relationship between weathered coal deposits and the etiology of Balkan endemic nephropathy
Field studies in epidemiology and environmental geochemistry in areas in Yugoslavia containing villages with a high incidence of Balkan endemic nephropathy (BEN), indicate a possible relationship between the presence of low-rank coal deposits and the etiology of BEN. Preliminary results from qualitative chemical analyses of drinking water from shallow farm wells indicate the presence of soluble po
Authors
G. L. Feder, Z. Radovanovic, R. B. Finkelman
Role of sediment-trace element chemistry in water-quality monitoring and the need for standard analytical methods
Multiple linear regression models calculated from readily obtainable chemical and physical parameters can explain a high percentage (70% or greater) of observed sediment trace-element variance for Cu, Zn, Pb, Cr, Ni, Co, As, Sb, Se, and Hg. Almost all the factors used in the various models fall into the category of operational definitions (e.g., grain size, surface area, and geochemical substrates
Authors
Arthur J. Horowitz
Satellite and earth science data management activities at the U.S. geological survey's EROS data center
The U.S. Geological Survey's Earth Resources Observation Systems (EROS) Data Center, the national archive for Landsat data, has 20 years of experience in acquiring, archiving, processing, and distributing Landsat and earth science data. The Center is expanding its satellite and earth science data management activities to support the U.S. Global Change Research Program and the National Aeronautics
Authors
David M. Carneggie, Gary G. Metz, William C. Draeger, Ralph J. Thompson