Regional stratigraphic framework of surficial sediments and bedrock beneath Lake Ontario
D. R. Hutchinson, C.F. Lewis, G. Hund
1993, Geographie Physique et Quaternaire (47) 337-352
Approximately 2550 km of single-channel high-resolution seismic reflection profiles have been interpreted and calibrated with lithological and geochronological information from four representative piston cores and one grab sample to provide a regional stratigraphie framework for the subbottom deposits of Lake Ontario. Five units overlying Paleozoic bedrock were identified and mapped....
Modeling transport processes in the coastal ocean
A.F. Blumberg, R. P. Signell, H. L. Jenter
1993, Journal of Environmental Engineering (1) 31-52
No abstract available....
Transport and natural attenuation of Cu, Zn, As, and Fe in the acid mine drainage of Leviathan and Bryant Creeks
Jenny G. Webster, D. Kirk Nordstrom, Kathleen S. Smith
1993, Book chapter, Environmental geochemistry of sulfide oxidation
The Leviathan and Bryant Creek (LBC) drainage system, on the border of California and Nevada, flows through overburden and waste from a former open-pit sulfur mine. The drainage contains acid mine waters with high concentrations of several trace elements, including Cu, Zn, and As, derived from oxidative weathering of sulfides...
Importance of model parameterization in finite fault inversions: Application to the 1974 Mw 8.0 Peru Earthquake
Stephen H. Hartzell, Charley Langer
1993, Journal of Geophysical Research B: Solid Earth (98) 22123-22134
The spatial and temporal slip distributions for the October 3, 1974 (Mw = 8.0), Peru subduction zone earthquake and its largest aftershock on November 9 (Ms = 7.1) are calculated and analyzed in terms of the inversion parameterization and tectonic significance. Teleseismic, long-period World-Wide Standard Seismograph Network, P and SH...
Formation of left-lateral fractures within the Summit Ridge Shear Zone, 1989 Loma Prieta, California, Earthquake
Arvid M. Johnson, Robert W. Fleming
1993, Journal of Geophysical Research B: Solid Earth (98) 21823-21837
The 1989 Loma Prieta, California, earthquake is characterized by the lack of major, throughgoing, coseismic, right-lateral faulting along strands of the San Andreas fault zone in the epicentral area. Instead, throughout the Summit Ridge area there are zones of tension cracks and left-lateral fracture zones oriented about N45°W, that is,...
Deformation from 1973 through 1991 in the epicentral area of the 1992 Landers, California, Earthquake (Ms = 7.5)
James C. Savage, Michael Lisowski, M. Murray
1993, Journal of Geophysical Research B: Solid Earth (98) 19951-19958
Deformation of a 50 × 60 km trilateration network that spans the epicenter of the 1992 Landers earthquake(Ms = 7.5) was measured by seven surveys over the 19 years preceding the earthquake. Three moderate earthquakes (1979 Homestead Valley, Ms = 5.6; 1986 North Palm Springs, Ms = 6.0; and 1992 Joshua Tree, Ms =...
Modeling the effects of climate change on the thermal structure of Yellowstone Lake
Steven W. Hostetler, John Varley
1993, Park Science (13) 16
No abstract available....
Numerical investigation of steady liquid water flow in a variably saturated fracture network
Edward M. Kwicklis, Richard W. Healy
1993, Water Resources Research (29) 4091-4102
Numerical simulation was used to study steady liquid water movement in a 5-m by 5-m vertical section containing a hypothetical fracture network under conditions of variable saturation. The fracture network was assumed to be embedded within an impermeable rock matrix. Three variations of a network were considered. The “mixed” network...
Chlorofluorocarbons (CCl3F and CCl2F2) as dating tools and hydrologic tracers in shallow groundwater of the Delmarva Peninsula, Atlantic Coastal Plain, United States
S.A. Dunkle, Niel Plummer, E. Busenberg, P. J. Phillips, J. M. Denver, P. A. Hamilton, R. L. Michel, T.B. Coplen
1993, Water Resources Research (29) 3837-3860
Concentrations of the Chlorofluorocarbons (CFCs) CFC-11 and CFC-12 were determined in groundwater from coastal plain sediments of the Delmarva Peninsula. CFC-modeled ages were calculated independently for CFC-11 and CFC-12, and agreed to within 2–3 years in the majority of the waters. Recharge temperatures, determined from dissolved...
Adaptive estimation of the log fluctuating conductivity from tracer data at the Cape Cod Site
F.W. Deng, J.H. Cushman, J.W. Delleur
1993, Water Resources Research (29) 4011-4018
An adaptive estimation scheme is used to obtain the integral scale and variance of the log-fluctuating conductivity at the Cape Cod site based on the fast Fourier transform/stochastic model of Deng et al. (1993) and a Kalmanlike filter. The filter incorporates prior estimates of the unknown parameters with...
Modelling the seasonality of subsurface light and primary production in the Arabian Sea
John Brock, Shubha Sathyendranath, Trevor Platt
1993, Marine Ecology Progress Series (101) 209-221
Seasonal changes in mixed-layer depth and phytoplankton biomass in the Arabian Sea are assessed with climatologies of ship-based hydrographic measurements and ocean-color observations from satellite. At the close of the intermonsoons in November and especially May, the open Arabian Sea resembles the stereotypic, unperturbed tropical ocean, with a thin oligotrophic...
Impact crater outflows on Venus: Morphology and emplacement mechanisms
D. John Chadwick, Gerald G. Schaber
1993, Journal of Geophysical Research E: Planets (98) 20891-20902
Many of the 932 impact craters discovered by the Magellan spacecraft at Venus are associated with lobate flows that originate at or near the crater rim. They extend for several to several hundred kilometers from the crater, and they commonly have a strong radar backscatter. A morphologic study of all...
Rock-forming metals and Pb in modern Alaskan snow
Todd K. Hinkley
1993, Journal of Geophysical Research D: Atmospheres (98) 20537-20545
Metal concentrations in annual and subannual increments of snowpack from the accumulation zone of a south central Alaska glacier indicate that the deposition of Pb with and upon snow is decoupled from that of rock dusts. Rock dusts accumulate, apparently as dry deposition, on the topmost, exposed surfaces of snowpacks...
Controls on geyser periodicity
S. E. Ingebritsen, S.A. Rojstaczer
1993, Science (262) 889-892
Geyser eruption frequency is not constant over time and has been shown to vary with small (≤10–6) strains induced by seismic events, atmospheric loading, and Earth tides. The geyser system is approximated as a permeable conduit of intensely fractured rock surrounded by a less permeable rock matrix. Numerical simulation of...
Estimation of lipids and lean mass of migrating sandpipers
Susan K. Skagen, Fritz L. Knopf, Brian S. Cade
1993, The Condor (95) 944-956
Estimation of lean mass and lipid levels in birds involves the derivation of predictive equations that relate morphological measurements and, more recently, total body electrical conductivity (TOBEC) indices to known lean and lipid masses. Using cross-validation techniques, we evaluated the ability of several published and new predictive equations to estimate...
An analytic solution of the stochastic storage problem applicable to soil water
P. C. D. Milly
1993, Water Resources Research (29) 3755-3758
The accumulation of soil water during rainfall events and the subsequent depletion of soil water by evaporation between storms can be described, to first order, by simple accounting models. When the alternating supplies (precipitation) and demands (potential evaporation) are viewed as random variables, it follows that soil-water storage, evaporation, and...
Modeling steady-state methanogenic degradation of phenols in groundwater
Barbara A. Bekins, E. Michael Godsy, Donald F. Goerlitz
1993, Journal of Contaminant Hydrology (14) 279-294
Field and microcosm observations of methanogenic phenolic compound degradation indicate that Monod kinetics governs the substrate disappearance but overestimates the observed biomass. In this paper we present modeling results from an ongoing multidisciplinary study of methanogenic biodegradation of phenolic compounds in a sand and gravel aquifer contaminated...
Correction of stream quality trends for the effects of laboratory measurement bias
Richard B. Alexander, Richard A. Smith, Gregory E. Schwarz
1993, Water Resources Research (29) 3821-3833
We present a statistical model relating measurements of water quality to associated errors in laboratory methods. Estimation of the model allows us to correct trends in water quality for long-term and short-term variations in laboratory measurement errors. An illustration of the bias correction method for a large national set of...
Growth and mortality of larval sunfish in backwaters of the upper Mississippi River
S. J. Zigler, Cecil A. Jennings
1993, Transactions of the American Fisheries Society (122) 1080-1087
We estimated the growth and mortality of larval sunfish Lepomis spp. in backwater habitats of the upper Mississippi River with an otolith‐based method and a length‐based method. Fish were sampled with plankton nets at one station in Navigation Pools 8 and 14 in 1989 and at two stations in...
Prolonged swimming performance of northern squawfish
Matthew G. Mesa, Todd M. Olson
1993, Transactions of the American Fisheries Society (122) 1104-1110
We determined the prolonged swimming performance of two size-classes of northern squawfish Ptychocheilus oregonensis at 12 and 18°C. The percentage of fish fatigued was positively related to water velocity and best described by an exponential model. At 12°C, the velocity at which 50% of the fish fatigued (FV50) was estimated...
Economics and the national oil and gas assessment: The case of onshore northern Alaska
Emil D. Attanasi, Kenneth J. Bird, R. F. Mast
1993, American Association of Petroleum Geologists Bulletin (77) 491-504
The National Oil and Gas Assessment of undiscovered recoverable conventional oil and gas resources assigned nearly 36% of the undiscovered U.S. onshore oil resources and 28% of the commercially developable undiscovered oil resources to onshore northern Alaska. Economic screening models were applied to the geologic play assessment to estimate the...
Optimization of an extraction procedure for the accurate determination of total tin in eighteen Geological Survey of Japan rock reference materials
H.N. Elsheimer
1993, Analytical Sciences (9) 681-685
A fusion-extraction procedure for the determination of total tin in rocks and sediments by graphite furnace atomic absorption spectrometry (GFAAS) was reexamined and modified to obtain the optimum accuracy and precision. Several variations based on increases in the sample weight or extraction ratio were compared based on the determination of...
Simulating the volatilization of solvents in unsaturated soils during laboratory and field infiltration experiments
H. Jean Cho, Peter R. Jaffe, James A. Smith
1993, Water Resources Research (29) 3329-3342
This paper describes laboratory and field experiments which were conducted to study the dynamics of trichloroethylene (TCE) as it volatilized from contaminated groundwater and diffused in the presence of infiltrating water through the unsaturated soil zone to the land surface. The field experiments were conducted at the Picatinny Arsenal, which...
Use of mesoscale models for simulation of seasonal weather and climate change for the Rocky Mountain States
R. A. Pielke, Jill Baron, T. Chase, J. Copeland, Timothy G.F. Kittel, T. J. Lee, R. Walko, W. Zeng
1993, Book, Second international conference/workshop on integrating geographic information systems and environmental modelling
No abstract available....
Sharpness of upper-mantle discontinuities determined from high-frequency reflections
H.M. Benz, J.E. Vidale
1993, Nature (365) 147-150
An understanding of the nature of seismic discontinuities in the Earth's upper mantle is important for understanding mantle processes: in particular, the amplitude and sharpness of these discontinuities are critical for assessing models of upper-mantle phase changes and chemical layering. So far, seismic studies aimed at determining the thickness and...
