What is worse than the “big one”?
R. A. Kerr
1988, Earthquakes & Volcanoes (USGS) (20) 213-218
The Whittier Narrows California earthquake sequence (local magnitude, Ml=5.9 or 1 October, 1987), which caused over $358 million damage, indicates that assessments of earthquake hazards in Los Angeles metropolitan area may be underestimated. the sequence ruptured a previously unidentified thrust fault that may be part of a large system of...
A magmatic model of Medicine Lake Volcano, California
J.M. Donnelly-Nolan
1988, Journal of Geophysical Research Solid Earth (93) 4412-4420
Medicine Lake volcano is a Pleistocene and Holocene shield volcano of the southern Cascade Range. It is located behind the main Cascade arc in an extensional tectonic setting where high-alumina basalt is the most commonly erupted lava. This basalt is parental to the higher-silica calc-alkaline and tholeiitic lavas that make...
HELIOTHERMAL LAKE MODEL OF BORATE DEPOSITION IN THE MIOCENE FURNACE CREEK FORMATION, DEATH VALLEY REGION, CALIFORNIA.
Charles E. Barker, James M. Barker
Grayson S.J.Smith D.A., editor(s)
1988, Conference Paper, Preprint - Society of Mining Engineers of AIME
Heliothermal lakes are density-stratified with shallow submerged margins surrounding areally restricted deep pool(s) containing a dense brine overlain by a much less dense brine. The reflective brine interface allows solar energy to be trapped in the dense brine which may warm to over 90 degree C. Carbonate precipitated from the...
Coastal geomorphology of arctic Alaska
Peter W. Barnes, Stuart E. Rawlinson, Erk Reimnitz
1988, Technical Council on Cold Regions Engineering Monograph 3-30
The treeless, tundra-plain of northern Alaska merges with the Arctic Ocean along a coastal area characterized by low tundra bluffs, and sparse coastal and delta dunes. Coastal engineering projects that aggrade or degrade permafrost will alter the geomorphology and rates of coastal processes by changing coastal stability. Similarly, projects that...
The growth of geological structures by repeated earthquakes: 2, Field examples of continental dip-slip faults
R.S. Stein, G.C.P. King, J. B. Rundle
1988, Journal of Geophysical Research Solid Earth (93) 13319-13331
A strong test of our understanding of the earthquake cycle is the ability to reproduce extant fault-bounded geological structures, such as basins and ranges, which are built by repeated cycles of deformation. Along strike-slip faults, the coseismic and interseismic deformation can be nearly equal in magnitude and opposite in sign,...
Applications of a simulation model to decisions in mallard management
L.M. Cowardin, Douglas H. Johnson, T.L. Shaffer, D. W. Sparling
1988, Fish and Wildlife Technical Report 17
A system comprising simulation models and data bases for habitat availability and nest success rates was used to predict results from a mallard (Anas platyrhynchos) management plan and to compare six management methods with a control. Individual treatments in the applications included land purchase for waterfowl production, wetland easement purchase,...
Characterization of humic acid fractions by C-13 nuclear magnetic resonance spectroscopy
Robert L. Wershaw, Kevin A. Thorn, D.J. Pinckney
1988, Environmental Technology Letters (9) 53-62
Soil humic acids from different environments were fractionated by adsorption chromatography on Sephadex and characterized by C‐13 nuclear magnetic resonance (NMR) spectroscopy. The C‐13 NMR spectra of the fractions consist of some sharp, well‐resolved lines and some broad bands in contrast to the spectra of the unfractionated humic acids, where...
The mechanics of ground deformation precursory to dome-building extrusions at Mount St. Helens 1981-1982
W.W. Chadwick Jr., R.J. Archuleta, D. A. Swanson
1988, Journal of Geophysical Research Solid Earth (93) 4351-4366
Detailed monitoring at Mount St. Helens since 1980 has enabled prediction of the intermittent eruptive activity (mostly dome growth) with unprecedented success. During 1981 and 1982, accelerating deformation of the crater floor around the vent (including radial cracks, thrust faults, and ground tilt) was the earliest indicator of impending activity....
A statistical method for estimating rates of soil development and ages of geologic deposits: A design for soil-chronosequence studies
P. Switzer, J.W. Harden, R. K. Mark
1988, Mathematical Geology (20) 49-61
A statistical method for estimating rates of soil development in a given region based on calibration from a series of dated soils is used to estimate ages of soils in the same region that are not dated directly. The method is designed specifically to account for sampling procedures and uncertainties...
Pb, Sr, and Nd isotopic compositions of a suite of Late Archean, igneous rocks, eastern Beartooth Mountains: Implications for crust-mantle evolution
J. L. Wooden, P.A. Mueller
1988, Earth and Planetary Science Letters (87) 59-72
A series of compositionally diverse, Late Archean rocks (2.74–2.79 Ga old) from the eastern Beartooth Mountains, Montana and Wyoming, U.S.A., have the same initial Pb, Sr, and Nd isotopic ratios. Lead and Sr initial ratios are higher and Nd initial ratios...
Using laser micro mass spectrometry with the LAMMA-1000 instrument for monitoring relative elemental concentrations in vitrinite
J.J. Morelli, D.M. Hercules, P.C. Lyons, C.A. Palmer, J.D. Fletcher
1988, Mikrochimica Acta (96) 105-118
The variation in relative elemental concentrations among a series of coal macerals belonging to the vitrinite maceral group was determined using laser micro mass spectrometry (LAMMS). Variations in Ba, Cr, Ga, Sr, Ti, and V concentrations among the coals were determined using the LAMM A-1000 instrument. LAMMS analysis is not...
Anomalous shear wave attenuation in the shallow crust beneath the Coso volcanic region, California
C. Sanders, P. Ho-Liu, D. Rinn, Kanamori Hiroo
1988, Journal of Geophysical Research Solid Earth (93) 3321-3338
We use seismograms of local earthquakes to image relative shear wave attenuation structure in the shallow crust beneath the region containing the Coso volcanic-geothermal area of eastern California. SV and P wave amplitudes were measured from vertical component seismograms of earthquakes that occurred in the Cososouthem Sierra Nevada region from July 1983 to August...
Vapor-dominated zones within hydrothermal systems: Evolution and natural state
S. E. Ingebritsen, M.L. Sorey
1988, Journal of Geophysical Research Solid Earth (93) 13635-13655
Three conceptual models illustrate the range of hydrothermal systems in which vapor-dominated conditions are found. The first model (model I) represents a system with an extensive near-vaporstatic vapor-dominated zone and limited liquid throughflow and is analogous to systems such as The Geysers, California. Such systems can evolve within low-permeability barriers...
Effects of three-dimensional velocity structure on the seismicity of the 1984 Morgan Hill, California, aftershock sequence
A.J. Michael
1988, Bulletin of the Seismological Society of America (78) 1199-1221
A three-dimensional velocity model for the area surrounding the 24 April 1984 Morgan Hill earthquake has been developed by simultaneously inverting local earthquake and refraction arrival-time data. This velocity model corresponds well to the surface geology of the region, predominantly showing a low-velocity region associated with the sedimentary sequence to...
The hydrothermal system at Newberry Volcano, Oregon
E.A. Sammel, S. E. Ingebritsen, Robert H. Mariner
1988, Journal of Geophysical Research Solid Earth (93) 10149-10162
Results of recent geological and geophysical studies at Newberry Volcano have been incorporated into conceptual and numerical models of a magma-based hydrothermal system. Numerical simulations begin with emplacement of a small magma body, the presumed source of silicic eruptions at Newberry that began about 10,000 B.P., into a thermal regime...
Precursory seismic quiescence: A preliminary assessment of the hypothesis
P.A. Reasenberg, M.V. Matthews
1988, Pure and Applied Geophysics PAGEOPH (126) 373-406
Numerous cases of precursory seismic quiescence have been reported in recent years. Some investigators have interpreted these observations as evidence that seismic quiescence is a somewhat reliable precursor to moderate or large earthquakes. However, because failures of the pattern to predict earthquakes may not, in general, be reported, and because...
An Angus/Argo study of the neovolcanic zone along the East Pacific rise from the Clipperton fracture zone to 12°N
E. Uchupi, W. C. Schwab, Richard D. Ballard, J.L. Cheminee, Jean Francheteau, R. Hekinian, D.K. Blackman, Haraldur Sigurdsson
1988, Geo-Marine Letters (8) 131-138
Still photographs and video images collected along the Neovolcanic Zone of the East Pacific Rise from 10°15′N to 11°53′N show that recent volcanic sheet flows, possibly less than 100 years old, are superimposed on an older sediment-laden pillow terrane. This recent activity is restricted to a narrow zone that crosses...
Three-dimensional gravity modeling of the geologic structure of Long Valley caldera
S. F. Carle
1988, Journal of Geophysical Research Solid Earth (93) 13237-13250
A 48-mGal gravity low coincides with Long Valley caldera and is mainly attributed to low-density caldera fill. Gravity measurements by Unocal Geothermal have been integrated with U.S. Geological Survey data, vastly improving gravity station coverage throughout the caldera. A strong regional gravity trend is mainly attributed to isostasy. A “best...
Depositional models for two Tertiary coal-bearing sequences in the Powder River Basin, Wyoming, USA
Peter D. Warwick, Ronald W. Stanton
1988, Journal of the Geological Society (145) 613-620
Depositional controls on peat-forming environments which produce thick (>10m) coal beds can be inferred from relationships between coal bed geometry, maceral composition and associated lithologies. Study of these relationships within sedimentary sequences associated with the Wyodak-Anderson (Palaeocene) and the Felix (Eocene) sub-bituminous coal beds in the Powder River Basin,...
Regional assessment of pumpage in southeastern Virginia
Pixie A. Hamilton
1988, Conference Paper
A U.S. Geological Survey investigation was conducted, in cooperation with the Virginia Water Control Board, to analyze the hydrogeology and groundwater flow system in the Coastal Plain physiographic province of southeastern Virginia, and to assess the continued reliability of groundwater as a freshwater resource. To provide a more detailed analysis...
Crustal velocities near Coalinga, California, modeled from a combined earthquake/explosion refraction profile
N. Macgregor-Scott, A. Walter
1988, Bulletin of the Seismological Society of America (78) 1475-1490
Crustal velocity structure for the region near Coalinga, California, has been derived from both earthquake and explosion seismic phase data recorded along a NW-SE seismic-refraction profile on the western flank of the Great Valley east of the Diablo Range. Comparison of the two data sets reveals P-wave phases in common...
Two-dimensional Lagrangian simulation of suspended sediment
David H. Schoellhamer
1988, Journal of Hydraulic Engineering (114) 1192-1209
A two‐dimensional laterally averaged model for suspended sediment transport in steady gradually varied flow that is based on the Lagrangian reference frame is presented. The layered Lagrangian transport model (LLTM) for suspended sediment performs laterally averaged Lagrangian calculations with steady or unsteady upstream boundary concentration. The elevations of nearly horizontal...
Age and petrology of alkalic postshield and rejuvenated-stage lava from Kauai, Hawaii
D.A. Clague, G. B. Dalrymple
1988, Contributions to Mineralogy and Petrology (99) 202-218
At the top of the Waimea Canyon Basalt on the island of Kauai, rare flows of alkalic postshield-stage hawaiite and mugearite overlie tholeiitic flows of the shield stage. These postshield-stage flows are 3.92 Ma and provide a younger limit for the age of the tholeiitic shield stage. The younger Koloa...
Forecast model for great earthquakes at the Nankai Trough subduction zone
W.D. Stuart
1988, Pure and Applied Geophysics PAGEOPH (126) 619-641
An earthquake instability model is formulated for recurring great earthquakes at the Nankai Trough subduction zone in southwest Japan. The model is quasistatic, two-dimensional, and has a displacement and velocity dependent constitutive law applied at the fault plane. A constant rate of fault slip at depth represents forcing due to...
Late Wisconsinan-Holocene paleogeography of Delaware Bay; a large coastal plain estuary
H.J. Knebel, C.H. Fletcher III, J.C. Kraft
1988, Marine Geology (83) 115-133
Analyses of an extensive grid of seismic reflection profiles along with previously published core data and modern sedimentary environment information from surrounding coastal areas permit an outline of the paleogeography of the large Delaware Bay estuary during the last transgression of sea level. During late Wisconsinan times, the Delaware River...
