Seismic stratigraphy of the Mississippi-Alabama shelf and upper continental slope
J. L. Kindinger
1988, Marine Geology (83) 79-94
The Mississippi-Alabama shelf and upper continental slope contain relatively thin Upper Pleistocene and Holocene deposits. Five stages of shelf evolution can be identified from the early Wisconsinan to present. The stages were controlled by glacioeustatic or relative sea-level changes and are...
Composition and stable-isotope geochemistry of natural gases from Kansas, Midcontinent, U.S.A.
P.D. Jenden, K.D. Newell, I.R. Kaplan, W.L. Watney
1988, Chemical Geology (71) 117-147
More than 28??1012 ft.3 (79??1010 m3) of natural gas and 5.3??109 bbl (8.4??108 m3) of oil have been produced in Kansas, U.S.A., from Paleozoic carbonate and sandstone reservoirs on structural uplifts and shallow embayments along the northern margin of the Anadarko basin. A heavily-explored, geologically well-characterized state, Kansas is an...
Fate of acetone in an outdoor model stream in southern Mississippi, U.S.A.
R. E. Rathbun, D. W. Stephens, D.J. Shultz, D. Y. Tai
1988, Journal of Hydrology (104) 181-209
The fate of acetone in water was investigated in an outdoor model stream located in southern Mississippi, U.S.A. Acetone was injected continuously for 32 days resulting in small milligram-perliter concentrations in the stream. Rhodamine-WT dye was injected at the beginning and at the end of the study to determine the...
Nationwide regression models for predicting urban runoff water quality at unmonitored sites
Gary D. Tasker, N. E. Driver
1988, Water Resources Bulletin (24) 1091-1101
Regression models are presented that can be used to estimate mean loads for chemical oxygen demand, suspended solids, dissolved solids, total nitrogen, total ammonia plus nitrogen, total phosphorous, dissolved phosphorous, total copper, total lead, and total zinc at unmonitored sites in urban areas. Explanatory variables include drainage area, imperviousness of...
A simple model for strong ground motions and response spectra
Erdal Safak, Charles Mueller, John Boatwright
1988, Earthquake Engineering and Structural Dynamics (16) 203-215
A simple model for the description of strong ground motions is introduced. The model shows that response spectra can be estimated by using only four parameters of the ground motion, the RMS acceleration, effective duration and two corner frequencies that characterize the effective frequency band of the motion. The model...
The information content of high-frequency seismograms and the near-surface geologic structure of "hard rock" recording sites
E. Cranswick
1988, Pure and Applied Geophysics PAGEOPH (128) 333-363
Due to hardware developments in the last decade, the high-frequency end of the frequency band of seismic waves analyzed for source mechanisms has been extended into the audio-frequency range (>20 Hz). In principle, the short wavelengths corresponding to these frequencies can provide information about the details of seismic sources, but...
Detailed record of SO2 emissions from Pu'u `O`o between episodes 33 and 34 of the 1983-86 ERZ eruption, Kilauea, Hawaii
T.A. Chartier, William I. Rose Jr., J. B. Stokes
1988, Bulletin of Volcanology (50) 215-228
A tripod-mounted correlation spectrometer was used to measure SO2 emissions from Pu`u `O`o vent, mid-ERZ, Kilauea, Hawaii between Episodes 33 and 34 (June 13 to July 6, 1985). In 24 repose days, 906 measurements were collected, averaging 38 determinations/day. Measurements reflect 13% of the total 576 hours of the repose...
The origin of Chubutolithes Ihering, ichnofossils from the Eocene and Oligocene of Chubut Province, Argentina.
T.M. Brown, B.C. Ratcliffe
1988, Journal of Paleontology (62) 163-167
The distinctive trace fossil Chubutolithes gaimanensis n. ichnosp. occurs in Casamayoran (early Eocene) and Colhuéhaupian (late Oligocene) alluvial rocks of the Sarmiento Formation in eastern Chubut Province, Argentina. Though known for nearly 70 years, its origin has remained obscure. Examination of new specimens and comparisons with modern analogs...
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 and three-dimensional internal structure of active magmatic systems: Kilauea volcano, Hawaii
M.P. Ryan
1988, Journal of Geophysical Research Solid Earth (93) 4213-4248
Interpretation of abundant seismic data suggests that Kilauea's primary conduit within the upper mantle is concentrically zoned to about 34-km depth. This zoned structure is inferred to contain a central core region of relatively higher permeability, surrounded by numerous dikes that are in intermittent hydraulic communication with each other and...
New trend- trigonometric model for interpolation and prediction of the geomagnetic field utilizing the new DGRF models
L.R. Alldredge
1988, Journal of Geomagnetism & Geoelectricity (40) 749-759
At the IUGG Assembly at Vancouver during August 1987 new definitive geomagnetic reference field (DGRF) models to degree 10 for 1945, 1950, 1955, and 1960 were adopted by IAGA. Before these new DGRF models were accepted, the author developed a trend and trigonometric model (old trig model) based on the...
Further comments on sensitivities, parameter estimation, and sampling design in one-dimensional analysis of solute transport in porous media
Debra S. Knopman, Clifford I. Voss
1988, Water Resources Research (24) 225-238
Sensitivities of solute concentration to parameters associated with first-order chemical decay, boundary conditions, initial conditions, and multilayer transport are examined in one-dimensional analytical models of transient solute transport in porous media. A sensitivity is a change in solute concentration resulting from a change in a model parameter. Sensitivity analysis is...
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...
Resonance of a fluid-driven crack: Radiation properties and implications for the source of long-period events and harmonic tremor
B. Chouet
1988, Journal of Geophysical Research Solid Earth (93) 4375-4400
A dynamic source model is presented, in which a three-dimensional crack containing a viscous compressible fluid is excited into resonance by an impulsive pressure transient applied over a small area ΔS of the crack surface. The crack excitation depends critically on two dimensionless parameters called the crack stiffness, C = (b/μ)(L/d), and...
Deformation in the Yakataga seismic gap, Southern Alaska, 1980-1986
J.C. Savage, M. Lisowski
1988, Journal of Geophysical Research Solid Earth (93) 4731-4744
A 60-by-40-km trilateration network in the Yakataga seismic gap was surveyed in 1980, 1982, 1984, and 1986 with precise electro-optical distance-measuring equipment to measure strain accumulation. The overall deformation is roughly approximated by a 0.24±0.03 µstrain/yr N32°W±2.4° uniaxial contraction that is uniform in time. However, the spatial distribution of deformation...
The seismic radiation from composite models of faulting
J. Boatwright
1988, Bulletin of the Seismological Society of America (78) 489-508
The failure of an asperity, i.e., the dynamic rupture of a small fault area with finite stress drop surrounded by a broken or weak fault area which has no stress drop but which slips after the asperity fails, is proposed as a model for the rupture process of a subevent...
Failure of self-similarity for large (Mw > 81/4) earthquakes
S.H. Hartzell, T. H. Heaton
1988, Bulletin of the Seismological Society of America (78) 478-488
Compares teleseismic P-wave records for earthquakes in the magnitude range from 6.0-9.5 with synthetics for a self-similar, omega 2 source model and conclude that the energy radiated by very large earthquakes (Mw > 81/4) is not self-similar to that radiated from smaller earthquakes (Mw < 81/4). Furthermore, in the period...
Absence of strain accumulation in the Shumagin seismic gap, Alaska, 1980-1987
M. Lisowski, J.C. Savage, W.H. Prescott, W.K. Gross
1988, Journal of Geophysical Research Solid Earth (93) 7909-7922
Measurements of the deformation of a trilateration network in the Shumagin seismic gap in the interval 1980–1987 failed to detect any significant strain accumulation (observed extension rate in the direction of plate convergence 0.00±0.03 μstrain/yr). Dislocation models of the subduction process and measurements at a comparable network at a known...
Variation of depth to the brittle-ductile transition due to cooling of a midcrustal intrusion
M. E. Gettings
1988, Geophysical Research Letters (15) 213-216
The depth to the brittle-ductile transition in the crust is often defined by the intersection of a shear resistance relation in the brittle upper crust that increases linearly with depth and a power law relation for ductile flow in the lower crust that depends strongly on...
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...
Analytical approach to calculation of response spectra from seismological models of ground motion
Erdal Safak
1988, Earthquake Engineering and Structural Dynamics (16) 121-134
An analytical approach to calculate response spectra from seismological models of ground motion is presented. Seismological models have three major advantages over empirical models: (1) they help in an understanding of the physics of earthquake mechanisms, (2) they can be used to predict ground motions for future earthquakes and (3)...
