Microbial H2 cycling does not affect δ2H values of ground water
J. E. Landmeyer, F. H. Chapelle, P. M. Bradley
2000, Ground Water (38) 376-380
Stable hydrogen-isotope values of ground water (δ2H) and dissolved hydrogen concentrations (H(2(aq)) were quantified in a petroleum-hydrocarbon contaminated aquifer to determine whether the production/consumption of H2 by subsurface microorganisms affects ground water &delta2H values. The range of &delta2H observed in monitoring wells sampled (-27.8 ‰c to -15.5 ‰c) was best...
Homing and movement of yellow-phase American eels in freshwater ponds
P. J. Lamothe, M. Gallagher, D.P. Chivers, J.R. Moring
2000, Environmental Biology of Fishes (58) 393-399
Ten yellow-phase American eels, Anguilla rostrata, were captured from Hammond Pond, a small freshwater pond located in central Maine, U.S.A. The eels were implanted with radio transmitters and released into nearby Hermon Pond. At the same time, 10 eels were captured from Hermon Pond, implanted with radio transmitters and returned...
Diet of first-feeding larval and young-of-the-year white sturgeon in the lower Columbia River
W.D. Muir, G.T. McCabe Jr., M.J. Parsley, S.A. Hinton
2000, Northwest Science (74) 25-33
In some Snake and Columbia River reservoirs, adult white sturgeon (Acipenser transmontanus) are common but few juvenile fish are found, indicating a lack of spawning success or poor survival of larvae. In contrast, recruitment of young-of-the-year white sturgeon to juvenile and adult stages is successful in the unimpounded Columbia River...
Guidelines for model calibration and application to flow simulation in the Death Valley regional groundwater system
M. C. Hill, F. A. D’Agnese, C.C. Faunt
2000, Conference Paper, IAHS-AISH Publication
Fourteen guidelines are described which are intended to produce calibrated groundwater models likely to represent the associated real systems more accurately than typically used methods. The 14 guidelines are discussed in the context of the calibration of a regional groundwater flow model of the Death Valley region in the southwestern...
Non-native grasses and fires create double jeopardy
T. Esque, C. Schwalbe
2000, People, Land, and Water 26
No abstract available at this time...
Effects of neck bands on survival of greater snow geese
S. Menu, J.B. Hestbeck, G. Gauthier, A. Reed
2000, Journal of Wildlife Management (64) 544-552
Neck bands are a widely used marker in goose research. However, few studies have investigated a possible negative effect of this marker on survival. We tested the effect of neck bands on the survival of adult female greater snow geese (Chen caerulescens atlantica) by marking birds with either a neck...
Testing assumptions for unbiased estimation of survival of radiomarked harlequin ducks
Daniel Esler, Daniel M. Mulcahy, Robert L. Jarvis
2000, Journal of Wildlife Management (64) 591-598
Unbiased estimates of survival based on individuals outfitted with radiotransmitters require meeting the assumptions that radios do not affect survival, and animals for which the radio signal is lost have the same survival probability as those for which fate is known. In most survival studies, researchers have made these assumptions...
Earthquake stress triggers, stress shadows, and seismic hazard
R.A. Harris
2000, Current Science (79) 1215-1225
Many aspects of earthquake mechanics remain an enigma at the beginning of the twenty-first century. One potential bright spot is the realization that simple calculations of stress changes may explain some earthquake interactions, just as previous and ongoing studies of stress changes have begun to explain human- induced seismicity. This...
Viscoelastic-coupling model for the earthquake cycle driven from below
J.C. Savage
2000, Journal of Geophysical Research B: Solid Earth (105) 25525-25532
In a linear system the earthquake cycle can be represented as the sum of a solution which reproduces the earthquake cycle itself (viscoelastic-coupling model) and a solution that provides the driving force. We consider two cases, one in which the earthquake cycle is driven by stresses transmitted along the schizosphere...
Energy budgets of mining-induced earthquakes and their interactions with nearby stopes
Art McGarr
2000, Conference Paper, International Journal of Rock Mechanics and Mining Sciences
In the early 1960's, N.G.W. Cook, using an underground network of geophones, demonstrated that most Witwatersrand tremors are closely associated with deep level gold mining operations. He also showed that the energy released by the closure of the tabular stopes at depths of the order of 2 km was more...
Fracture process zone in granite
A. Zang, F.C. Wagner, S. Stanchits, C. Janssen, G. Dresen
2000, Journal of Geophysical Research B: Solid Earth (105) 23651-23661
In uniaxial compression tests performed on Aue granite cores (diameter 50 mm, length 100 mm), a steel loading plate was used to induce the formation of a discrete shear fracture. A zone of distributed microcracks surrounds the tip of the propagating fracture. This process zone is imaged by locating acoustic...
Parent brine of the castile evaporites (Upper Permian), Texas and New Mexico
Douglas W. Kirkland, Rodger E. Denison, Walter E. Dean
2000, Journal of Sedimentary Research (70) 749-761
The Upper Permian (lower Ochoan) Castile Formation is a major evaporite sequence (∼10,000 km3) of calcite, anhydrite, and halite in west Texas and southeastern New Mexico. Traditionally the Castile brine has been considered to have been derived from seawater. This tradition has recently been challenged by two versions of the...
Factors associated with plant species richness in a coastal tall-grass prairie
James B. Grace, Larry K. Allain, Charles Allen
2000, Journal of Vegetation Science (11) 443-452
In this study we examine the factors associated with variations in species richness within a remnant tall-grass prairie in order to gain insight into the relative importance of controlling variables. The study area was a small, isolated prairie surrounded by wetlands and located within the coastal prairie region, which occurs...
Fire and exotic grasses changing Mojave's face
M.L. Brooks, T. C. Esque
2000, People, Land, and Water 25-25
No abstract available at this time...
Formation of natural gas hydrates in marine sediments. Gas hydrate growth and stability conditioned by host sediment properties
M. B. Clennell, P. Henry, M. Hovland, J.S. Booth, W.J. Winters, M. Thomas
2000, Conference Paper, Annals of the New York Academy of Sciences
The stability conditions of submarine gas hydrates (methane clathrates) are largely dictated by pressure, temperature, gas composition, and pore water salinity. However, the physical properties and surface chemistry of the host sediments also affect the thermodynamic state, growth kinetics, spatial distributions, and growth forms of clathrates. Our model presumes that...
Comparisons of in situ and core gas measurements in ODP Leg 164 bore holes
C. K. Paull, T.D. Lorenson, G. Dickens, W.S. Borowski, W. Ussler III, K. Kvenvolden
2000, Conference Paper, Annals of the New York Academy of Sciences
During Ocean Drilling Program Leg 164, an unprecedented effort was made to determine the amounts of gas and gas hydrate in the sediments from Sites 994, 995, and 997. For the first time in the history of academic drilling, a pressure core sampler (PCS) worked well enough to generate an...
Pesticides in the atmosphere of the Mississippi River Valley, part I: Rain
M.S. Majewski, W.T. Foreman, D. A. Goolsby
2000, Science of Total Environment (248) 201-212
Weekly composite rainfall samples were collected in three paired urban and agricultural regions of the Midwestern United States and along the Mississippi River during April–September 1995. The paired sampling sites were located in Mississippi, Iowa, and Minnesota. A background site, removed from dense urban and agriculture...
Photoenhanced toxicity of weathered oil to Mysidopsis bahia
L. Cleveland, E. E. Little, R.D. Calfee, M.G. Barron
2000, Aquatic Toxicology (49) 63-76
The toxicity of a water-accommodated fraction (WAF) prepared from weathered oil was assessed in a 7-day static renewal test with Mysidopsis bahia. Weathered oil was collected from the 5 x monitoring well at the Guadalupe oil field. Solar ultraviolet and visible light intensities were measured in various habitats in the...
A fascination with birds
Jill A. Dechant
2000, Prairie Naturalist (31) 189-190
No abstract available....
Application of GPS and GIS to map channel features in Walnut Creek, Iowa
K. E. Schilling, C.F. Wolter
2000, Journal of the American Water Resources Association (36) 1423-1434
A 12-km reach of Walnut Creek was mapped at the Neal Smith National Wildlife Refuge in Jasper County, Iowa to identify and prioritize areas of the stream channel in need of further investigation or restoration. Channel features, including streambank conditions, bottom sediment materials and thickness, channel cross-sections, debris dams, tile...
Geothermal convection: a mechanism for dolomitization at Enewetak Atoll?
A.M. Wilson, W. Sanford, F. Whitaker, P. Smart
2000, Book, Journal of Geochemical Exploration
Geothermal convection in carbonate platforms could drive massive dolomitization by supplying mass transport of magnesium over long periods and at temperatures high enough to overcome kinetic limitations. Reactive-transport simulations based on Enewetak Atoll show dolomitization in a thin band at a permeability contrast near the base of the platform, which...
Isotope hydrology dynamics of riverine wetlands in the Kankakee Watershed, Indiana
W.C. Sidle, L. Arihood, R. Bayless
2000, Journal of the American Water Resources Association (36) 771-790
Wetland restoration activities may disturb shallow ground-water flow dynamics. There may be unintentional sources of water flowing into a constructed wetland that could compromise the long-term viability of a wetland function. Measurement of naturally-occurring isotopes in the hydrosphere can provide an indication of provenance, flow paths or components, and residence...
Pore fluid pressure, apparent friction, and Coulomb failure
N.M. Beeler, R.W. Simpson, S.H. Hickman, D.A. Lockner
2000, Journal of Geophysical Research B: Solid Earth (105) 25533-25542
Many recent studies of stress-triggered seismicity rely on a fault failure model with a single free parameter, the apparent coefficient of friction, presumed to be a material constant with possible values 0 ≤ μ′ ≤ 1. These studies may present a misleading view of fault strength and the role of...
Scientific meeting raises awareness of amphibian decline in Asia
Vance Vredenburg, Yuezhao Wang, Gary M. Fellers
2000, Newsletter of the Declining Amphibian Populations Task Force of the World (42)
Blood samples from 433 Peregrine Falcons (Falco peregrinus) during fall and spring migrations, 1976-80, indicated that most of their pesticide burden, primarily DDE, was accumulated on wintering grounds in Latin America. DDE in spring migrants returning from Latin America for the first time declined significantly from 1979 to 1980. Only...
Application of a modified harness design for attachment of radio transmitters to shorebirds
Peter M. Sanzenbacher, Susan M. Haig, Lewis W. Oring
2000, Wader Study Group Bulletin (91) 16-20
Radio transmitter attachment methodology is important to the design of radio telemetry studies. In 1998, we attached 5 transmitters to a captive population of Western Sandpipers (Calidris mauri) and 7 transmitters to wild Killdeer (Charadriusv ociferus) using a modified version of the Rappole and Tipton (1991) figure-8 leg-loop harness. Captive...
