Measurement of variation in soil solute tracer concentration across a range of effective pore sizes
Judson W. Harvey
1993, Water Resources Research (29) 1831-1837
Solute transport concepts in soil are based on speculation that solutes are distributed nonuniformly within large and small pores. Solute concentrations have not previously been measured across a range of pore sizes and examined in relation to soil hydrological properties. For this study, modified pressure cells were used to measure...
Dioxin-like toxic potency in Forster's tern eggs from Green Bay, Lake Michigan, North America
D. E. Tillitt, T.J. Kubiak, G.T. Ankley, J. P. Giesy
1993, Chemosphere (26) 2079-2084
The endangered Forster's tern (Sternaforsteri) population on Green Bay, Wisconsin has exhibited symptoms of embryotoxicity, congenital deformities, and poor hatching success. The putative causal agents are planar halogenated hydrocarbons (PHH). The objectives of this study were: 1) to evaluate the toxic potency of PHHs in extracts of Forster's tern eggs...
Toward the simulation of the effects of the Great Lakes on regional climate
Gary T. Bates, F. Giorgi, Steven W. Hostetler
1993, Monthly Weather Review (121) 1373-1387
This paper describes a set of numerical experiments aimed at evaluating the feasibility of applying a version of the National Center for Atmospheric Research-Pennsylvania State University regional model (MM4) to regional climate simulation over the Great Lakes Basin. The objectives of this initial modeling investigation are 1) to examine whether...
Developmental stability and its applications in ecotoxicology
John H. Graham, John M. Emlen, D. Carl Freeman
1993, Ecotoxicology (2) 175-184
Developmental stability refers to the ability of a developing organism to produce a consistent phenotype in a given environment. It provides a simple, reliable method of detecting stressed populations and monitoring their recovery. The most common measure of developmental instability, fluctuating asymmetry, assesses minor deviations from perfect bilateral symmetry in...
How geometrical constraints contribute to the weakness of mature faults
D.A. Lockner, J.D. Byerlee
1993, Nature (363) 250-252
Increasing evidence that the San Andreas fault has low shear strength1 has fuelled considerable discussion regarding the role of fluid pressure in controlling fault strength. Byerlee2,3 and Rice4 have shown how fluid pressure gradients within a fault zone can produce a fault with low strength while avoiding hydraulic fracture of the surrounding rock...
The Parkfield prediction fallacy
James C. Savage
1993, Bulletin of the Seismological Society of America (83) 1-6
The Parkfield earthquake prediction is generally stated as a 95% probability that the next moderate earthquake there should occur before January 1993. That time limit is based on a two-sided 95% confidence interval. Because at the time of the prediction (1985) it was already clear that the earthquake had not...
Rainfall-threshold conditions for landslides in a humid-tropical system
Matthew C. Larsen, Andrew Simon
1993, Geografiska Annaler, Series A: Physical Geography (75A) 13-23
Landslides are triggered by factors such as heavy rainfall, seismic activity, and construction on hillslopes. The leading cause of landslides in Puerto Rico is intense and/or prolonged rainfall. A rainfall threshold for rainfall-triggered landsliding is delimited by 256 storms that occurred between 1959 and 1991 in the central mountains of...
Geochemical evaluation of upper cretaceous fruitland formation coals, San Juan Basin, New Mexico and Colorado
G.E. Michael, D.E. Anders, B. E. Law
1993, Organic Geochemistry (20) 475-498
Geochemical analyses of coal samples from the Upper Cretaceous Fruitland Formation in the San Juan Basin of New Mexico and Colorado were used to determine thermal maturity, type of kerogen, and hydrocarbon generation potential. Mean random vitrinite reflectance (%Rm) of the Fruitland coal ranges from 0.42 to 1.54%. Rock-Eval pyrolysis...
Instream flows according to the ASCE model state water code
G. W. Sherk, Berton Lee Lamb
1993, Book, Water management in the '90s: a time for innovation: proceedings of the 20th anniversary conference
No abstract available....
Northward displacements of forearc slivers in the Coast Ranges of California and Southwest Oregon during the late Mesozoic and early Cenozoic
A. S. Jayko, M.C. Blake Jr.
1993, Book chapter, Mesozoic paleogeography of the Western United States
North American-Farallon-Kula plate motion data, combined with estimated strikeslip displacements obtained from the obliquity of convergence along active circumPacific subduction zones, can be used to estimate the amount of strike-slip displacement along the forearc region of western North America. This evidence suggests a minumum of 500 km and maximum of...
Evidence for subduction of a major ocean plate along the California margin during the Middle to Early Late Jurassic
B.L. Murchey, M.C. Blake Jr.
1993, Book chapter, Mesozoic paleogeographyof the Western United States
No abstract available ...
Chronostratigraphic assignment of volcanopelagic strata above the Coast Range Ophiolite
D.M. Hull, E.A. Pessagno Jr., C.D. Blome, C.A. Hopson, I.M. Munoz
G.C. Dunne, editor(s)
1993, Book chapter, Mesozoic paleogeography of the Western United States
No abstract available ...
U-Pb Zircon Geochronology of the Emigrant Gap Composite Pluton, Northern Sierra Nevada, California: Implications for the Nevadan Orogeny
G. H. Girty, S. Yoshinobu, M.D. Wracher, M.S. Girty, K.A. Bryan, J.E. Skinner, B.A. McNulty, K.A. Bracchi, D. S. Harwood, R.E. Hanson
1993, Book chapter, Mesozoic paleogeography of the Western United States
The undeformed Emigrant Gap composite pluton postdates the Lower to Middle Jurassic Sailor Canyon and Middle Jurassic Tuttle Lake Formations. According to earlier workers, these latterformations contain main and late phase Nevadan-aged (155 +/-3 Ma) spaced, slaty, phyllitic, and crenulation cleavage. Recently discovered fossils indicate that the upper part of...
Drilling successful from ROV Ventana
D.S. Stakes, James A. R. McFarlane, G. Leon Holloway, H. Gary Greene
1993, Eos Science News (74) 210-211
Cores of granite and deformed sediment from the walls of Monterey Canyon were successfully recovered from December 30 to 31, 1992, by Monterey Bay Aquarium Research Institute's (MBARI) Remotely Operated Vehicle (ROV) Ventana using a small-diameter, double-barrel drill with a diamond bit. This HSTR (Holloway-Stakes-Tengdin-Rajcula) drill was developed to drill cores horizontally...
First results of a deep tow CHIRP sonar seafloor imaging system
M. Parent, Changle Fang, Thomas F. O’Brien, William W. Danforth
1993, Conference Paper
The latest and most innovative technology has been applied towards the development of a full-ocean depth multi-sensor sonar system using linear swept-FM (Chirp) technology. The seafloor imaging system (SIS- 7000) described herein uses Chirp sidescan sonar to provide high resolution imagery at long range, and Chirp subbottom sonar to provide...
Concentrations, distribution, and sources of selenium from irrigated lands in western United States
R. A. Engberg, M. A. Sylvester
1993, Journal of Irrigation and Drainage Engineering (119) 522-536
Concentrations, distribution, and sources of selenium from irrigated lands were studied between 1986 and 1990 at 20 reconnaissance project areas in 17 western states under the Department of Interior's National Irrigation Water Quality Program. Samples of water, bottom sediment, whole‐body fish, and bird livers for analysis of selenium concentrations were...
An improved method for quantifying soil macroporosity
V. R. Vermeul, J.D. Istok, A. L. Flint, J.L. Pikul
1993, Soil Science Society of America Journal (57) 809-816
Quantitative information on macroporosity is needed to predict water flow and solute transport in field soils. A method was developed for determining the number, shape, and size distribution of soil macropores. Horizontal serial sections sawed from paraffin-impregnated soil cores were photographed under ultraviolet (UV) light. Anthracene, mixed with the paraffin,...
Body composition of wintering canvasbacks in Louisiana: Dominance and survival implications
William L. Hohman
1993, Condor (95) 377-387
I studied effects of sex, age, and month on body mass and composition of Canvasbacks (Aythya valisineria) at Catahoula Lake (CL) and the Mississippi River Delta (MRD), Louisiana, in winter 1987-1988. Size-adjusted body mass and fat varied by age, month, and site. Fat levels in immatures were greater at MRD...
A Geographic Information System procedure to quantify drainage-basin characteristics
David A. Eash
1993, Conference Paper, Proceedings of the Symposium on Geographic Information Systems and Water Resources
The Basin Characteristics System (BCS) has been developed to quantify characteristics of a drainage basin. The first of four main BCS processing steps creates four geographic information system (GIS) digital maps representing the drainage divide, the drainage network, elevation contours, and the basin length. The drainage divide and basin...
A spatial simulation model of hydrology and vegetation dynamics in semi-permanent prairie wetlands
Karen A. Poiani, W. Carter Johnson
1993, Ecological Applications (3) 279-293
The objective of this study was to construct a spatial simulation model of the vegetation dynamics in semi-permanent prairie wetlands. A hydrologic submodel estimated water levels based on precipitation, runoff, and potential evapotranspiration. A vegetation submodel calculated the amount and distribution of emergent cover and open water using a geographic...
Sediment export by ice rafting from a coastal Polynya, Arctic Alaska, U.S.A.
Erk Reimnitz, Michael McCormick, Kristin McDougall-Reid, Elisabeth M. Brouwers
1993, Arctic and Alpine Research (25) 83-98
Strong offshore winds in early 1989 produced a shore polynya that reached along the entire north coast of Alaska and eastward beyond the mouth of the Mackenzie River in Canada. From January through April, this open water periodically exposed the shelf to sediment entrainment by suspension freezing. This process requires...
Conceptual model for quantifying pre-smolt production from flow-dependent physical habitat and water temperature
S. C. Williamson, J. M. Bartholow, C. B. Stalnaker
1993, Regulated Rivers: Research & Management (8) 15-28
A conceptual model has been developed to test river regulation concepts by linking physical habitat and water temperature with salmonid population and production in cold water streams. Work is in progress to examine numerous questions as part of flow evaluation and habitat restoration programmes in the...
A laboratory and field evaluation of a portable immunoassay test for triazine herbicides in environmental water samples
P.A. Schulze, P. D. Capel, P. J. Squillace, D.R. Helsel
1993, International Journal of Environmental Analytical Chemistry (53) 307-319
The usefulness and sensitivity, of a portable immunoassay test for the semiquantitative field screening of water samples was evaluated by means of laboratory and field studies. Laboratory results indicated that the tests were useful for the determination of atrazine concentrations of 0.1 to 1.5 μg/L. At a concentration of...
Mussels: The forgotten fauna of regulated rivers. A case study of the Caney Fork River
James B. Layzer, Mark E. Gordon, Robert M. Anderson
1993, Regulated Rivers: Research & Management (8) 63-71
During the past century freshwater mussel populations have declined precipitously throughout North America. Much of this loss has resulted from the construction of dams. In the Cumberland River system, 23% (22 species) of the historic mussel fauna is extinct or listed as endangered. Several additional species have either been extirpated...
Harvesting and replenishment policies for renewable natural resources
Aaron J. Douglas, Richard L. Johnson
1993, Journal of Environmental Management (38) 27-42
The current paper links the optimal intertemporal use of renewable natural resources to the harvesting activities of various economic agents. Previous contributions cite market forces as a causative factor inducing the extirpation of renewable natural resources. The analysis given here discusses investment in the stock of renewable resources and cites...
