Correlation of ash-flow tuffs
W. Hildreth, G. Mahood
1985, Geological Society of America Bulletin (96) 968-974
Discrimination and correlation of ash-flow sheets is important in structurally complex, long-lived volcanic fields where such sheets provide the best keys to the regional stratigraphic framework. Three-dimensional complexities resulting from pulsatory eruptions, sectorial emplacement, mechanical sorting during outflow, thermal and compositional zoning of...
Forecasts and predictions of eruptive activity at Mount St. Helens, USA: 1975-1984
D. A. Swanson, T. J. Casadevall, D. Dzurisin, R. T. Holcomb, C. G. Newhall, S. D. Malone, C.S. Weaver
1985, Journal of Geodynamics (3) 397-423
Public statements about volcanic activity at Mount St. Helens include factual statements, forecasts, and predictions. A factual statement describes current conditions but does not anticipate future events. A forecast is a comparatively imprecise statement of the time, place, and nature of expected activity. A prediction is a comparatively precise statement of the time, place, and ideally,...
Geochemistry of great Salt Lake, Utah II: Pleistocene-Holocene evolution
R. J. Spencer, H.P. Eugster, B.F. Jones
1985, Geochimica et Cosmochimica Acta (49) 739-747
Sedimentologic and biostratigraphic evidence is used to develop a geochemical model for Great Salt Lake, Utah, extending back some 30,000 yrs. B.P. Hydrologie conditions as defined by the water budget equation are characterized by a lake initially at a low, saline stage, rising by about 17,000 yrs. B.P. to fresh...
Summary of data on the age of the Orca Group, Alaska: A section in The United States Geological Survey in Alaska: Accomplishments during 1984
George Plafker, Gerta Keller, Steven W. Nelson, Julie A. Dumoulin, Marti L. Miller
1985, Circular 967
The Orca Group is a widespread, thick, complexly deformed accretionary sequence of flysch and tholeiitic basalt in the Prince William Sound area (Winkler, 1976; Winkler and Plafker, 1981) (fig. 49). Despite a number of extensive field studies of the Orca Group, reliable data on the age of the unit have...
Mechanistic roles of soil humus and minerals in the sorption of nonionic organic compounds from aqueous and organic solutions
C. T. Chiou, T.D. Shoup, P.E. Porter
1985, Organic Geochemistry (8) 9-14
Mechanistic roles of soil humus and soil minerals and their contributions to soil sorption of nonionic organic compounds from aqueous and organic solutions are illustrated. Parathion and lindane are used as model solutes on two soils that differ greatly in their humic and mineral contents. In aqueous systems, observed sorptive...
Validation of an automated fluorescein method for determining bromide in water
M. J. Fishman, L.J. Schroder, L.C. Friedman
1985, Water Research (19) 497-501
Surface, atmospheric precipitation and deionized water samples were spiked with ??g l-1 concentrations of bromide, and the solutions stored in polyethylene and polytetrafluoroethylene bottles. Bromide was determined periodically for 30 days. Automated fluorescein and ion chromatography methods were used to determine bromide in these prepared samples. Analysis of the data...
MAJOR SOURCE OF SIDE-LOOKING AIRBORNE RADAR IMAGERY FOR RESEARCH AND EXPLORATION: THE U. S. GEOLOGICAL SURVEY.
Allan N. Kover, John Edwin Jones
Carver Keith R., editor(s)
1985, Conference Paper, Digest - International Geoscience and Remote Sensing Symposium (IGARSS)
The US Geological Survey (USGS) instituted a program in 1980 to acquire side-looking airbore radar (SLAR) data and make these data readily available to the public in a mosaic format comparable to the USGS 1:250,000-scale topographic map series. The SLAR data are also available as strip images at an acquisition...
SURVEYS OF COASTAL STRUCTURES USING GEOPHYSICAL TECHNIQUES.
John R. Dingler, Roberto J. Anima
Billy L. Edge, editor(s)
1985, Conference Paper, Proceedings of the Coastal Engineering Conference
During the summer of 1983 and the spring and summer of 1984, the authors conducted side scan sonar and shallow subbottom surveys in conjunction with bathymetric and diving surveys along three northern California coastal structures to determine the condition of the structures before extensive damage occurred. Then the applicability of...
SEISMIC STUDY OF THE AGUA DE PAU GEOTHERMAL PROSPECT, SAO MIGUEL, AZORES.
Phillip B. Dawson, Antonio Rodrigues da Silva, H. M. Iyer, John R. Evans
1985, Conference Paper, Transactions - Geothermal Resources Council
A 16 station array was operated over the 200 km**2 central portion of Sao Miguel utilizing 8 permanent Instituto Nacional de Meterologia e Geofisica stations and 8 USGS portable stations. Forty four local events with well constrained solutions and 15 regional events were located. In addition, hundreds of unlocatable seismic...
PREPRO: a computer program for encoding regional exploration data for use in characteristic analysis
N.J. Bridges, J.T. Hanley, R.B. McCammon
1985, Computers & Geosciences (11) 513-519
The preprocessor (PREPRO) computer program offers the exploration geologist a variety of options for encoding regional exploration data into ternary form for use in characteristic analysis. PREPRO's options include variable-input formats, cursor input, ordering among a set of input variables, and selectable ternary transformations. Moreover, the program provides for the...
Electrical geophysical investigations of massive sulfide deposits and their host rocks, West Shasta copper-zinc district
R. J. Horton, B. D. Smith, J.C. Washburne
1985, Economic Geology (80) 2213-2229
The West Shasta copper-zinc district, Shasta County, California, contains many volcanogenic sulfide deposits within Middle Devonian rhyolites that have not been highly metamorphosed. The district was selected by the U.S. Geological Survey for intensive geological, geochemical, and geophysical study under the Development of Assessment Techniques (DAT) project because accessible exposures...
Time scales of change in the San Francisco Bay benthos
F.H. Nichols, J.K. Thompson
1985, Hydrobiologia (129) 121-138
Results from multi-year investigations in the San Francisco Bay estuary show that large abundance fluctuations within benthic macroinvertebrate populations reflect both (1) within-year periodicity of reproduction, recruitment, and mortality that is not necessarily coincident with seasonal changes of the environment (e.g., the annual temperature cycle), and (2) aperiodic density changes...
Wave energy saturation on a natural beach of variable slope
A. H. Sallenger Jr., R.A. Holman
1985, Journal of Geophysical Research - Oceans (90) 11939-11944
Time series of flow were measured across the inner surf zone during a storm. These data were used to quantify the dependence of wave height (transformed from measured flow) and velocity on local slope and depth. Similar to previous studies, as incident waves broke and propagated into the surf zone,...
NEW STUDIES OF URBAN FLOOD FREQUENCY IN THE SOUTHEASTERN UNITED STATES.
Vernon B. Sauer
Huffsey Ralph R.De Vore R.William, editor(s)
1985, Conference Paper, University of Kentucky, Office of Engineering Services, (Bulletin) UKY BU
Five reports dealing with flood magnitude and frequency in urban areas in the Southeastern United States have been published during the past 2 years by the U. S. Geological Survey. These reports are based on data collected in Tampa and Tallahassee, Florida, Atlanta, Georgia, and several cities in Alabama and...
LIQUEFACTION POTENTIAL OF SEDIMENT IN THE NORTHERN BERING SEA.
William J. Winters
Chaney Ronald C.Demars Kenneth R., editor(s)
1985, Conference Paper, ASTM Special Technical Publication
The liquefaction potential of sediment in Norton Sound and the northern Bering Sea was evaluated by estimating the liquefaction susceptibility of the material from in-situ and laboratory tests in terms of earthquake and wave loads required to liquefy the material, and then comparing estimated behavior with anticipated loadings caused by...
Solid state recording current meter conversion
Ralph T. Cheng, Lichen Wang
1985, Conference Paper, Oceans Conference Record (IEEE)
The authors describe the conversion of an Endeco-174 current meter to a solid-state recording current meter. A removable solid-state module was designed to fit in the space originally occupied by an 8-track tape cartridge. The module contains a CPU and 128 kilobytes of nonvolatile CMOS memory. The solid-state module communicates...
Aeromagnetic map and analysis of aeromagnetic and aeroradioactivity data in the Blood Mountain, Chattahoochee, and Tray Mountain Roadless Areas, northern Georgia
David L. Daniels
1985, Miscellaneous Field Studies Map 1347-E
The data for the aerornagnetic map of the Blood Mountain, Chattahoochee, and Tray Mountain Roadless Areas and vicinity were compiled from two separate airborne surveys {U.S. Geological Survey, 1977, 1981) produced in cooperation with the State of Georgia. These surveys were flown by fixed - wing aircraft in 1976 and...
A preliminary evaluation of hydrology and water quality near the Tacoma landfill, Pierce County, Washington
W. E. Lum, G. L. Turney
1985, Water-Resources Investigations Report 84-4351
The Tacoma landfill, located in western Pierce County, Washington, has been used for the disposal of waste since about 1960. Disposal operations are planned to continue at this site until at least 1990. Data were compiled and interpreted to help understand the possible effects of the landfill on water quality...
Digital to analog conversion and visual evaluation of Thematic Mapper data
James R. McCord, Douglas R. Binnie, Paul M. Seevers
1985, Journal of Imaging Technology (11) 125-130
As a part of the National Aeronautics and Space Administration Landsat D Image Data Quality Analysis Program, the Earth Resources Observation Systems Data Center (EDC) developed procedures to optimize the visual information content of Thematic Mapper data and evaluate the resulting photographic products by visual interpretation. A digital-to-analog transfer function...
The need for accuracy in modelling: An example
Douglas H. Johnson, Michael J. Conroy, James D. Nichols
1985, Ecological Modelling (30) 157-161
The need for accurate information in modelling depends on the objectives of the effort, but trustworthy data are essential for a model intended for use in the management of natural resources. This point is illustrated by referring to a recently published model of canvasback ducks. We demonstrate that several key...
SIMULATING FLOW IN THE TIDAL POTOMAC RIVER.
Raymond W. Schaffranek
1985, Conference Paper
A one-dimensional unsteady flow model has been applied to the tidal Potomac River, including its major tributaries and marginal embayments, between Washington, D. C. and Indian Head, Md. The computer model has been calibrated to simulate the combined effects of tide, freshwater inflows, and wind conditions governing flow in the...
Benthic fluxes in San Francisco Bay
Douglas E. Hammond, C. Fuller, D. Harmon, Blayne Hartman, M. Korosec, L.G. Miller, R. Rea, S. Warren, W. Berelson, S.W. Hager
1985, Hydrobiologia (129) 69-90
Measurements of benthic fluxes have been made on four occasions between February 1980 and February 1981 at a channel station and a shoal station in South San Francisco Bay, using in situ flux chambers. On each occasion replicate measurements of easily measured substances such as radon, oxygen, ammonia, and silica...
Improving waterfowl production estimates: Results of a test in the prairie pothole region
P.M. Arnold, L.M. Cowardin
1985, International Congress of Game Biologists (17) 859-865
The U.S. Fish and Wildlife Service in an effort to improve and standardize methods for estimating waterfowl production tested a new technique in the four-county Arrowwood Wetland Management District (WMD) for three years (1982-1984). On 14 randomly selected 10.36 km2 plots, upland and wetland habitat was mapped, classified, and digitized....
Adjustment of geochemical background by robust multivariate statistics
D. Zhou
1985, Journal of Geochemical Exploration (24) 207-222
Conventional analyses of exploration geochemical data assume that the background is a constant or slowly changing value, equivalent to a plane or a smoothly curved surface. However, it is better to regard the geochemical background as a rugged surface, varying with changes in geology and environment. This rugged surface can...
Trace element content of gossans at four mines in the West Shasta massive sulfide district
R. F. Sanzolone, J. A. Domenico
1985, Economic Geology (80) 2206-2212
We evaluated the trace element content of gossans at four mines in the West Shasta Cu-Zn mining district in California. We found little difference in trace element content between the chipped rock rind and whole-rock gossan samples. Gossans derived from disseminated sulfides were found to have a lower trace element...
