Migration of historical earthquakes in California
C.-Y. King, Z. Ma
1988, Pure and Applied Geophysics PAGEOPH (127) 627-639
Most large earthquakes of magnitude ???6.0 in California during 1852-1987 appear to show a southeast-to-northwest tendency of epicenter migration. This finding is consistent with earlier findings of Savage (1971) for a relatively few large earthquakes along the west coast of North America, and of Wood and Allen (1973) for smaller...
Pedogenic replacement of aluminosilicate grains by CaCO3 in Ustollic Haplargids, south-central Montana, U.S.A.
Marith C. Reheis
1988, Geoderma (41) 243-261
A chronosequence of calcic soils formed on granitic glaciofluvial terrace deposits of Rock Creek and the Clarks Fork in south-central Montana shows progressive replacement of aluminosilicate parent-material grains by calcium-magnesium carbonate. The terraces range from late Pliocene to Holocene in age as dated by tephrochronology, correlation, and stream incision rates....
Generation of pyroclastic flows and surges by hot-rock avalanches from the dome of Mount St. Helens volcano, USA
R.A. Mellors, R. B. Waitt, D. A. Swanson
1988, Bulletin of Volcanology (50) 14-25
Several hot-rock avalanches have occurred during the growth of the composite dome of Mount St. Helens, Washington between 1980 and 1987. One of these occurred on 9 May 1986 and produced a fan-shaped avalanche deposit of juvenile dacite debris together with a more extensive pyroclastic-flow deposit. Laterally thinning deposits and...
Rare earth elements in the phosphatic-enriched sediment of the Peru shelf
D.Z. Piper, P. A. Baedecker, J.G. Crock, W. C. Burnett, B.J. Loebner
1988, Marine Geology (80) 269-285
Apatite-enriched materials from the Peru shelf have been analyzed for their major oxide and rare earth element (REE) concentrations. The samples consist of (1) the fine fraction of sediment, mostly clay material, (2) phosphatic pellets and fish debris, which are dispersed throughout the fine-grained sediment, (3) tabular-shaped phosphatic crusts, which...
Accumulation and bioconcentration of polycyclic aromatic hydrocarbons in a nearshore estuarine environment near a Pensacola (Florida) creosote contamination site
J. F. Elder, P.V. Dresler
1988, Environmental Pollution (49) 117-132
Long-term accumulation of creosote wastes at a wood-preserving facility near Pensacola, Florida, has produced high levels of organic contamination of groundwaters near Pensacola Bay. Impacts of this contamination on the nearshore environment of the bay were examined by analysis of water, sediment and tissues of two mollusc species. One of...
Geochemistry of groundwater in tertiary and cretaceous sediments of the southeastern Coastal Plain in eastern Georgia, South Carolina, and southeastern North Carolina
Roger W. Lee, Donald J. Strickland
1988, Water Resources Research (24) 291-303
Geochemical samples of groundwater taken along hydrologic flow paths in eastern Georgia, South Carolina, and southeastern North Carolina, from noncalcareous sand aquifers, largely of Cretaceous age, are dominated by sodium and bicarbonate ions. Calcareous sand aquifers, largely of Tertiary age, contain water whose chemistry is dominated by calcium and bicarbonate...
General two‐point method for Determining velocity in open channel
John F. Walker
1988, Journal of Hydraulic Engineering (114) 801-805
The generally accepted procedure is to average velocity measurements at 0. 2D and 0. 8D, measured vertically from the water surface,or alternatively to measure velocity at a position equal to 0. 6D, where D is the total depth of flow. In some situations, one may wish to measure at depths...
Downslope Eulerian mean flow associated with high-frequency current fluctuations observed on the outer continental shelf and upper slope along the northeastern United States continental margin: Implications for sediment transport
B. Butman
1988, Continental Shelf Research (8) 811-840
Eulerian current measurements made 5-7 m above bottom at six stations along the United States east coast continental margin show a net downslope flow of 1-5 cm s-1. Although the scalar current speed decreases with water depth and toward the bottom, fluctuations in the cross-isobath flow were stronger and increasingly...
The role of mantle CO2 in volcanism
I. Barnes, William C. Evans, L. D. White
1988, Applied Geochemistry (3) 281-285
Carbon dioxide is the propellant gas in volcanic eruptions and is also found in mantle xenoliths. It is speculated that CO2 occurs as a free gas phase in the mantle because there is no reason to expect CO2 to be so universally associated with volcanic rocks unless the CO2 comes...
Stratigraphy and magnetic polarity of the high terrace remnants in the upper Ohio and Monongahela Rivers in West Virginia, Pennsylvania, and Ohio
R. B. Jacobson, D. P. Elston, John W. Heaton
1988, Quaternary Research (29) 216-232
A synthesis of previous work and new data on the stratigraphy of high terraces of the Ohio and Monongahela Rivers upstream from Parkersburg, West Virginia, indicates a correspondence between terrace histories in the ancient Teays and Pittsburgh drainage basins. Four terraces are identified in each. Sediments of the lower three...
Physical deposit measures and commercial potential: The case of titanium-bearing heavy-mineral deposits
E. D. Attanasi, J.H. DeYoung Jr.
1988, Mathematical Geology (20) 97-110
Physical measures of mineral deposit characteristics, such as grade and tonnage, long have been used in both subjective and analytic models to predict favorability of areas for the occurrence of mineral deposits of particular types. After a deposit has been identified, however, the explorationist must decide whether to continue data...
Waveform modelling using locked-mode synthetic and differential seismograms: application to determination of the structure of Mexico
J.S. Gomberg, T. Guy Masters
1988, Geophysical Journal International (94) 193-218
We have developed algorithms for modelling seismic waveforms to constrain regional Earth structure. The seismogram is represented as a sum of locked-mode travelling waves in a layered medium. This representation is convenient as it allows us to model structures with slowly varying heterogeneity and to construct differential seismograms. Describes the...
Multi-model approach to petroleum resource appraisal using analytic methodologies for probabilistic systems
R. A. Crovelli
1988, Mathematical Geology (20) 955-972
The geologic appraisal model that is selected for a petroleum resource assessment depends upon purpose of the assessment, basic geologic assumptions of the area, type of available data, time available before deadlines, available human and financial resources, available computer facilities, and, most importantly, the available quantitative methodology with corresponding computer...
Use of the truncated shifted Pareto distribution in assessing size distribution of oil and gas fields
J.C. Houghton
1988, Mathematical Geology (20) 907-937
The truncated shifted Pareto (TSP) distribution, a variant of the two-parameter Pareto distribution, in which one parameter is added to shift the distribution right and left and the right-hand side is truncated, is used to model size distributions of oil and gas fields for resource assessment. Assumptions about limits to...
Isotopic studies of epigenetic features in metalliferous sediment, Atlantis II Deep, Red Sea
Robert A. Zierenberg, Wayne C. Shanks III
1988, Canadian Mineralogist (26 pt 3) 737-753
The unique depositional environment of the Atlantis II Deep brine pool in the Red Sea produces a stratiform metalliferous deposit of greater areal extent than deposits formed by buoyant-plume systems typical of the midocean ridges because of much more efficient metal entrapment. Isotopic analyses of strontium, sulfur, carbon, and oxygen...
Food availability controls seasonal cycle of growth in Macoma balthica (L.) in San Francisco Bay, California
J.K. Thompson, F.H. Nichols
1988, Journal of Experimental Marine Biology and Ecology (116) 43-61
A 2-yr field study of growth in the bivalve Macoma balthica (L.) at four locations in San Francisco Bay, California, U.S., showed that the timing and rate of growth (increase in shell length) were related to food supply. This clam feeds on both planktonic and benthic microalgae, depending on availability....
On low-frequency errors of uniformly modulated filtered white-noise models for ground motions
Erdal Safak, David M. Boore
1988, Earthquake Engineering and Structural Dynamics (16) 381-388
Low-frequency errors of a commonly used non-stationary stochastic model (uniformly modulated filtered white-noise model) for earthquake ground motions are investigated. It is shown both analytically and by numerical simulation that uniformly modulated filter white-noise-type models systematically overestimate the spectral response for periods longer than the effective duration of the earthquake,...
Geologic history and palynologic dating of Paleocene deposits, western Rock Springs uplift, Sweetwater County, Wyoming
M.A. Kirschbaum, S.N. Nelson
1988, Contributions to Geology - University of Wyoming, Laramie (26) 21-28
During the latest Cretaceous or earliest Paleocene, a northwest-southeast trending anticline developed in the area of the present Rock springs uplift in southwestern Wyoming. This ancestral structure was eroded to a surface of fairly low relief on which a paleosol developed. The surface was formed on the Upper Cretaceous Almond...
Preliminary results of the Department of the Interior's irrigation drainage studies
Marc A. Sylvester, Jonathan P. Deason, Herman R. Feltz, Richard A. Engberg
1988, Conference Paper
The Department of the Interior, in 1986, began irrigation drainage studies in nine areas in seven Western states to determine whether irrigation drainage has caused or has the potential to cause harmful effects on human health, fish, and wildlife, or might reduce the suitability of water for beneficial uses. Results...
Simulation and video animation of canal flushing created by a tide gate
David H. Schoellhamer
1988, Conference Paper
A tide-gate algorithm was added to a one-dimensional unsteady flow model that was calibrated, verified, and used to determine the locations of as many as five tide gates that would maximize flushing in two canal systems. Results from the flow model were used to run a branched Lagrangian transport model...
Groundwater flow and transport modeling
Leonard F. Konikow, J.W. Mercer
1988, Journal of Hydrology (100) 379-409
Deterministic, distributed-parameter, numerical simulation models for analyzing groundwater flow and transport problems have come to be used almost routinely during the past decade. A review of the theoretical basis and practical use of groundwater flow and solute transport models is used to illustrate...
Aircraft MSS data registration and vegetation classification of wetland change detection
E.J. Christensen, J.R. Jensen, Elijah W. Ramsey III, H.E. Mackey Jr.
1988, International Journal of Remote Sensing (9) 23-38
Portions of the Savannah River floodplain swamp were evaluated for vegetation change using high resolution (5a??6 m) aircraft multispectral scanner (MSS) data. Image distortion from aircraft movement prevented precise image-to-image registration in some areas. However, when small scenes were used (200-250 ha), a first-order linear transformation provided registration accuracies of...
Extracting topographic structure from digital elevation data for geographic information-system analysis
Susan K. Jenson, Julia O. Domingue
1988, Photogrammetric Engineering and Remote Sensing (54) 1593-1600
Software tools have been developed at the U.S. Geological Survey's EROS Data Center to extract topographic structure and to delineate watersheds and overland flow paths from digital elevation models. The tools are specialpurpose FORTRAN programs interfaced with general-purpose raster and vector spatial analysis and relational data base management packages. The first...
Environmental impacts and regulatory policy. Implications of spray disposal of dredged material in Louisiana wetlands
Donald R. Cahoon, J.H. Cowan Jr.
1988, Coastal Management (16) 341-362
The capabilities of a new wetland dredging technology were assessed along with associated newly developed state and federal regulatory policies to determine if policy expectations realistically match the technological achievement. Current regulatory practices require amelioration of spoil bank impacts upon abandonment of an oil/gas well, but this may not occur...
The Land Analysis System (LAS) for multispectral image processing
S. W. Wharton, Y. C. Lu, Bruce K. Quirk, Lyndon R. Oleson, J. A. Newcomer, Frederick M. Irani
1988, IEEE Transactions on Geoscience and Remote Sensing (26) 693-697
The Land Analysis System (LAS) is an interactive software system available in the public domain for the analysis, display, and management of multispectral and other digital image data. LAS provides over 240 applications functions and utilities, a flexible user interface, complete online and hard-copy documentation, extensive image-data file management, reformatting,...
