Late Holocene vegetation changes in Greenwater Valley, Mojave Desert, California
K.L. Cole, R. H. Webb
1985, Quaternary Research (23) 227-235
Small-scale late Holocene vegetation changes were determined from a series of 13 modern and fossil packrat middens collected from a site in the Greenwater Valley, northern Mojave Desert, California. Although the site is above the modern lower limit of Coleogyne ramosissima (black-brush), macrofossils of this shrub are only present in...
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,...
Phase relations and adiabats in boiling seafloor geothermal systems
J. L. Bischoff, Kenneth S. Pitzer
1985, Earth and Planetary Science Letters (75) 327-338
Observations of large salinity variations and vent temperatures in the range of 380–400°C suggest that boiling or two-phase separation may be occurring in some seafloor geothermal systems. Consideration of flow rates and the relatively small differences in density between vapors and...
Crustal refraction profile of the Long Valley caldera, California, from the January 1983 Mammoth Lakes earthquake swarm
James H. Luetgert, Walter D. Mooney
1985, Bulletin of the Seismological Society of America (75) 211-221
Seismic-refraction profiles recorded north of Mammoth Lakes, California, using earthquake sources from the January 1983 swarm complement earlier explosion refraction profiles and provide velocity information from deeper in the crust in the area of the Long Valley caldera. Eight earthquakes from a depth range of 4.9 to 8.0 km confirm...
Subdivision of thick sedimentary units into layers for simulation of groundwater flow
J. S. Weiss, A. K. Williamson
1985, Groundwater (23) 767-774
Subdividing thick sedimentary units into model layers based solely on stratigraphy can lead to serious violation of groundwater flow modeling restraints and produce erroneous results. Borehole geophysical data can be used to suggest relative permeabilities and delineate model layers that are more likely to have uniform hydraulic properties than layers...
NORTH AMERICAN DATUM 1983 IMPLEMENTATION IMPACTS ON THE USGS NATIONAL MAPPING PROGRAM.
William J. Jones, Paul E. Needham
1985, Conference Paper, Technical Papers of the American Congress of Surveying and Mapping
The U. S. Geological Survey has previously experienced the impacts on the National Mapping Program that are associated with implementing a readjustment of the horizontal datum. The impacts of these past readjustments were minimal compared to those of the current readjustment. The Geological Survey currently has produced and published over...
Mineral, chemical and textural relationships in rhythmic-bedded, hydrocarbon-productive chalk of the Niobrara Formation, Denver Basin, Colorado ( USA).
R. M. Pollastro, C.J. Martinez
1985, Mountain Geologist (22) 55-63
The types of hydrocarbons produced from these chalks are determined by the level of thermal maturity associated with present-day burial or paleoburial conditions. Detailed analyses of deeply-buried chalk from core of the Smoky Hill Chalk Member of the Niobrara Formation in the Champlin Petroleum 2 Boxelder Farms well combined with...
Natural hazards activities of the National Geophysical Data Center
P. A. Lockridge
1985, Earthquake Information Bulletin (USGS) (17) 60-69
The National Geophysical Data Center (NGDC), a part of the National Oceanic and Atmospheric Administration, has been given the task of collecting, managing, and disseminating the great mass of inofmation produced by scientific observations of the geophysical environment. This article describes NGDC data bases that speifically relate to natural hazards. ...
Contaminant trends in lake trout (Salvelinus namaycush) of the upper Great Lakes
David S. DeVault, Wayne A. Willford, Robert J. Hesselberg
1985, Report
Contaminant body burdens in lake trout from the Upper Great Lakes have been monitored since 1970 on Lake Michigan and since 1977 and 1978 on Lakes Superior and Huron by USEPA, Great Lakes National Program Office and USFWS, Great Lakes Fishery Laboratory. Analysis of the Lake Michigan data shows that mean...
Hydrologic changes associated with the October 28, 1983, Idaho earthquake
R.L. Whitehead, R.W. Harper, H.G. Sisco
1985, Pure and Applied Geophysics PAGEOPH (122) 280-293
Significant hydrologic changes were observed after the magnitude 7.3 earthquake that occurred on October 28, 1983, in central Idaho. Groundwater levels rose by as much as 3 meters near the epicenter. Discharge in many streams and springs increased, in some instances by more than 100%. One warm spring ceased flowing...
Analysis of low levels of rare earths by radiochemical neutron activation analysis
G.A. Wandless, J. W. Morgan
1985, Journal of Radioanalytical and Nuclear Chemistry Articles (92) 273-282
A procedure for the radiochemical neutron-activation analysis for the rare earth elements (REE) involves the separation of the REE as a group by rapid ion-exchange methods and determination of yields by reactivation or by energy dispersive X-ray fluorescence (EDXRF) spectrometry. The U. S. Geological Survey (USGS) standard rocks, BCR-1 and...
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...
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,...
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...
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...
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...
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...
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...
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...
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...
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...
QUALITY ASSURANCE OF U. S. GEOLOGICAL SURVEY WATER-QUALITY FIELD MEASUREMENTS.
D. E. Erdmann, J.D. Thomas
1985, Conference Paper, ASTM Special Technical Publication
Reference samples are submitted semiannually to field analysts for measurement of these parameters with the same techniques and instruments used in the field. Both the personnel and the instruments involved in making the determinations are recorded. When the data are complete, a report defining the quality of the analytical results...
Determination of elastic wave velocity and relative hypocenter locations using refracted waves. I. Methodology
Kaye M. Shedlock, Lucile M. Jones, Xiufang Ma
1985, Bulletin of the Seismological Society of America (75) 427-439
An arrival time difference method utilizing refracted arrivals from earthquakes in a homogeneous, layered earth model has been developed for the simultaneous determination of near-source (in situ) velocity and relative locations of earthquakes. The method is particularly applicable when analyzing data from arrays in which most of the recording stations...
Experimental chemical weathering of various bedrock types at different pH-values. 1. Sandstone and granite
A.A. Afifi, O.P. Bricker, J.C. Chemerys
1985, Chemical Geology (49) 87-113
Experimental chemical weathering of the so-called Old Rag Granite and Massanutten Sandstone, Virginia, U.S.A., has produced a comparison with the natural environment, and prediction of the effect of acid precipitation. The experimental results of the release of elements, dissolution of minerals, total rock weathered and the degree of weathering...
