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Page 4654, results 116326 - 116350

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Publication Extents

Not all publications have extents, not all extents are completely accurate
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...
Tectonic evolution of Gorda Ridge inferred from sidescan sonar images
D.G. Masson, D.A. Cacchione, D.E. Drake
1988, Marine Geophysical Research (10) 191-204
Gorda Ridge is the southern segment of the Juan de Fuca Ridge complex, in the north-east Pacific. Along-strike spreading-rate variation on Gorda Ridge and deformation of Gorda Plate are evidence for compression between the Pacific and Gorda Plates. GLORIA sidescan sonographs allow the spreading fabric associated with Gorda Ridge to...
Oxygen isotope variations in granulite-grade iron formations: constraints on oxygen diffusion and retrograde isotopic exchange
Z.D. Sharp, J. R. O’Neil, E.J. Essene
1988, Contributions to Mineralogy and Petrology (98) 490-501
The oxygen isotope ratios of various minerals were measured in a granulite-grade iron formation in the Wind River Range, Wyoming. Estimates of temperature and pressure for the terrane using well calibrated geothermometers and geobarometers are 730??50?? C and 5.5??0.5 kbar. The mineral constraints on fluid compositions in the iron formation...
Bacterial ethane formation from reduced, ethylated sulfur compounds in anoxic sediments
R.S. Oremland, Michael J. Whiticar, F.E. Strohmaier, R.P. Kiene
1988, Geochimica et Cosmochimica Acta (52) 1895-1904
Trace levels of ethane were produced biologically in anoxic sediment slurries from five chemically different aquatic environments. Gases from these locations displayed biogenic characteristics, having 12C-enriched values of δ13CH4 (−62 to −86%.), δ13C2H6 (−35 to −55%.) and high ratios (720 to 140,000) of CH4[C2H6+ C3H8]">CH4[C2H6+ C3H8]. Endogenous...
On-line estimation of nonlinear physical systems
G. Christakos
1988, Mathematical Geology (20) 111-133
Recursive algorithms for estimating states of nonlinear physical systems are presented. Orthogonality properties are rediscovered and the associated polynomials are used to linearize state and observation models of the underlying random processes. This requires some key hypotheses regarding the structure of these processes, which may then take account of a...
Kleptoparasitism by bald eagles wintering in south-central Nebraska
Dennis G. Jorde, G.R. Lingle
1988, Journal of Field Ornithology (59) 183-188
Kleptoparasitism on other raptors was one means by which Bald Eagles (Haliaeetus leucocephalus) secured food along the North Platte and Platte rivers during the winters of 1978-1980. Species kelptoparasitized were Ferruginous Hawk (Buteo regalis), Red-tailed Hawk (B. jamaicensis), Rough-legged Hawk (B. lagopus), Golden Eagle (Aquila chrysaetos), and Bald Eagle. Stealing...
Variations in abundance of young-of-the-year channel catfish in a navigation pool of the upper Mississippi River
L. E. Holland Bartels, M.C. Duval
1988, Transactions of the American Fisheries Society (117) 202-208
Spatial and temporal variations in the abundance of young-of-the-year channel catfish Ictalurus punctatus were determined over 3 years based on 154 trawls taken from Navigation Pool 7 of the upper Mississippi River. No significant spatial patterns in abundance or length of fish in the catch were found...
The development of the continental margin of eastern North America-conjugate continental margin to West Africa
William P. Dillon, J. S. Schlee, Kim D. Klitgord
1988, Journal of African Earth Sciences (7) 361-367
The continental margin of eastern North America was initiated when West Africa and North America were rifted apart in Triassic-Early Jurassic time. Cooling of the crust and its thinning by rifting and extension caused subsidence. Variation in amounts of subsidence led to formation of five basins....
Geophysical study of a magma chamber near Mussau Island, Papua New Guinea
Shawn V. Dadisman, M. S. Marlow
1988, Book chapter, Geology and offshore resources of Pacific Island Arcs: New Ireland and Manus Region, Papa New Guinea
Analysis of a 24-channel seismic-reflection data collected near Mussau Island, Papua New Guinea, shows a high-amplitude, negative-polarity reflection that we believe is from the top of a magma chamber.  The reflecting horizon lies at a depth of about 4.4 s subbottom and can be traced laterally for 2.6 km.  On...
Air encapsulation during infiltration
Jim Constantz, W.N. Herkelrath, F. Murphy
1988, Soil Science Society of America Journal (52) 10-16
A series of field and laboratory experiments were performed to measure the effects of air encapsulation within the soil's transmission zone upon several infiltration properties. In the field, infiltration rates were measured using a double-cap infiltrometer (DCI), and soil-water contents were measured using time-domain reflectometry (TDR). Before half of the...
Processes affecting the distribution of selenium in shallow groundwater of agricultural areas, western San Joaquin Valley, California
S. J. Deverel, Roger Fujii
1988, Water Resources Research (24) 516-524
A study was undertaken to evaluate the processes affecting the chemistry of shallow groundwater associated with agricultural drainage systems in the western San Joaquin Valley, California. The study was prompted by a need for an understanding of selenium mobility in areas having high selenium concentrations in shallow groundwater. Groundwater samples...
The influence of diet quality on clutch size and laying pattern in mallards
J.L. Eldridge, Gary L. Krapu
1988, The Auk (105) 102-110
We measured the effect of diet quality on variation in the seasonal pattern of Mallard (Anas platyrhynchos) reproduction. Twenty wild-strain hens, consisting of 10 sibling pairs, were maintained in captivity. One sib of each pair was fed an enriched diet, and the other was fed wheat. The wheat diet resulted...
Response of well aquifer systems to Earth tides: Problem revisited
Paul A. Hsieh, John D. Bredehoeft, Stuart Rojstaczer
1988, Water Resources Research (24) 468-472
Two recent works cause us to reexamine Bredehoeft's (1967) analysis of earthtide response of water wells. Narasimhan et al. (1984) raise several questions regarding Bredehoeft's (1967) analysis and suggest that the analysis is internally inconsistent. They argue that one cannot directly estimate the specific storage, which characterizes the drained behavior...
Natural variance in pH as a complication in detecting acidification of lakes
J.T. Turk
1988, Water, Air, & Soil Pollution (37) 171-176
Natural variance in the pH of three dilute lakes in the Flat Tops Wilderness Area, Colorado, complicates the detection of acidification. Variations in pH during July-September of 1983 were: 0.95 (Ned Wilson Lake), 1.36 (Upper Island Lake), and 1.53 (Oyster Lake). Mean diurnal variations in pH during 1983 were: 0.37...
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...
Volcanic hazards and public response
D. W. Peterson
1988, Journal of Geophysical Research Solid Earth (93) 4161-4170
Although scientific understanding of volcanoes is advancing, eruptions continue to take a substantial toll of life and property. Some of these losses could be reduced by better advance preparation, more effective flow of information between scientists and public officials, and better understanding of volcanic behavior by all segments of the...
The Argos seismic data message system
J.S. Derr, R.N. Hunter
1988, Bulletin of the Seismological Society of America (78) 1000-1005
A reliable, inexpensive method for sending limited daily seismic data messages from remote observatories to the National Earthquake Information Center has been developed for use with the Argos satellite system. Data messages are compressed on a microcomputer and passed automatically to a simple transmitter. About 4 hr later, the data...
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...
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...
Parkfield, California, liquefaction prediction (USA)
T.L. Holzer, M.J. Bennett, T. L. Youd, A.T.F. Chen
1988, Bulletin of the Seismological Society of America (78) 385-389
The primary purpose of this short note is to formally record the liquefaction prediction (Holzer et al., 1986) made in connection with this predicted earthquake. In addition, this note serves to alert the seismic engineering community to special instrumentation being installed at the prediction site. The instrumentation will consist of...