Rupture models with dynamically determined breakdown displacement
D.J. Andrews
2004, Bulletin of the Seismological Society of America (94) 769-775
The critical breakdown displacement, Dc, in which friction drops to its sliding value, can be made dependent on event size by specifying friction to be a function of variables other than slip. Two such friction laws are examined here. The first is designed to achieve accuracy and smoothness in discrete...
Comparison of litter decomposition in a natural versus coal-slurry pond reclaimed as a wetland
J. Taylor, B.A. Middleton
2004, Land Degradation and Development (15) 439-446
Decomposition is a key function in reclaimed wetlands, and changes in its rate have ramifications for organic-matter accumulation, nutrient cycling, and production. The purpose of this study was to compare leaf litter decomposition rates in coal-slurry ponds vs. natural wetlands on natural floodplain wetlands in Illinois, USA. The rate of...
Reach-scale isotope tracer experiment to quantify denitrification and related processes in a nitrate-rich stream, midcontinent United States
J.K. Böhlke, J. W. Harvey, M.A. Voytek
2004, Limnology and Oceanography (49) 821-838
We conducted an in-stream tracer experiment with Br and 15N-enriched NO3- to determine the rates of denitrification and related processes in a gaining NO3- -rich stream in an agricultural watershed in the upper Mississippi basin in September 2001. We determined reach-averaged rates of N fluxes and reactions from isotopic analyses...
Mechanisms of electron acceptor utilization: Implications for simulating anaerobic biodegradation
M.E. Schreiber, G.R. Carey, D. T. Feinstein, J.M. Bahr
2004, Journal of Contaminant Hydrology (73) 99-127
Simulation of biodegradation reactions within a reactive transport framework requires information on mechanisms of terminal electron acceptor processes (TEAPs). In initial modeling efforts, TEAPs were approximated as occurring sequentially, with the highest energy-yielding electron acceptors (e.g. oxygen) consumed before those that yield less energy (e.g., sulfate). Within this framework in...
Nesting biology of three grassland passerines in the northern tallgrass prairie
Maiken Winter, Douglas H. Johnson, Jill A. Shaffer, W. Daniel Svedarsky
2004, The Wilson Bulletin (116) 211-223
Basic nesting information on grassland passerines is needed for improving grassland bird management. Among the information needs are (1) the suitability of nesting habitat, (2) periods during the breeding season in which birds are most vulnerable to disturbances, and (3) how to fit grasslands into a prioritization scheme for conservation....
Pacific and Atlantic Ocean influences on multidecadal drought frequency in the United States
G.J. McCabe, M.A. Palecki, J.L. Betancourt
2004, Proceedings of the National Academy of Sciences of the United States of America (101) 4136-4141
More than half (52%) of the spatial and temporal variance in multidecadal drought frequency over the conterminous United States is attributable to the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO). An additional 22% of the variance in drought frequency is related to a complex spatial pattern of...
Historical channel-bed elevation change as a result of multiple disturbances, Soldier Creek, Kansas
K. E. Juracek
2004, Physical Geography (25) 269-290
Historical information on stream stage/discharge relations from eight U.S. Geological Survey (USGS) streamflow-gaging stations was used to analyze channel-bed elevation change along Soldier Creek, a stream affected by multiple disturbances in northeast Kansas. The analysis provided information on the spatial (location, type, magnitude) and temporal (timing, duration, trend, rate) dimensions...
Fishes and habitat characteristics of the Keya Paha River, South Dakota-Nebraska
B. Harland, C. R. Berry Jr.
2004, Journal of Freshwater Ecology (19) 169-177
Fishes were collected in four mainstem reaches and eight tributary reaches in the Keya Paha River basin during May and June 2002. Most reaches were characteristically run habitats with sand substrates and riparian pastures. Data were combined with historical records to construct a basin-wide ichthyofaunal list which comprised 38 species...
Trace elements and common ions in southeastern Idaho snow: Regional air pollutant tracers for source area emissions
M. Abbott, J. Einerson, Peter Schuster, D. Susong, Howard E. Taylor
Benson S.A.Erickson T.A., editor(s)
2004, Conference Paper, Fuel Processing Technology
Snow sampling and analysis methods which produce accurate and ultra-low measurements of trace elements and common ion concentration in southeastern Idaho snow, were developed. Snow samples were collected over two winters to assess trace elements and common ion concentrations in air pollutant fallout across the southeastern Idaho. The area apportionment...
Development of a passive, in situ, integrative sampler for hydrophilic organic contaminants in aquatic environments
D.A. Alvarez, J. D. Petty, J.N. Huckins, T. L. Jones-Lepp, D.T. Getting, J.P. Goddard, S.E. Manahan
2004, Environmental Toxicology and Chemistry (23) 1640-1648
Increasingly it is being realized that a holistic hazard assessment of complex environmental contaminant mixtures requires data on the concentrations of hydrophilic organic contaminants including new generation pesticides, pharmaceuticals, personal care products, and many chemicals associated with household, industrial, and agricultural wastes. To address this issue, we developed a passive...
Analysis of modern and Pleistocene hydrologic exchange between Saginaw Bay (Lake Huron) and the Saginaw Lowlands area
J. R. Hoaglund III, J.J. Kolak, D.T. Long, G.J. Larson
2004, Geological Society of America Bulletin (116) 3-15
Two numerical models, one simulating present groundwater flow conditions and one simulating ice-induced hydraulic loading from the Port Huron ice advance, were used to characterize both modern and Pleistocene groundwater exchange between the Michigan Basin and near-surface water systems of Saginaw Bay (Lake Huron) and the surrounding Saginaw Lowlands area....
Triggered deformation and seismic activity under Mammoth Mountain in Long Valley caldera by the 3 November 2002 Mw 7.9 Denali fault earthquake
M.J.S. Johnston, S. G. Prejean, D.P. Hill
2004, Bulletin of the Seismological Society of America (94) S360-S369
The 3 November 2002 Mw 7.9 Denali fault earthquake triggered deformational offsets and microseismicity under Mammoth Mountain (MM) on the rim of Long Valley caldera, California, some 3460 km from the earthquake. Such strain offsets and microseismicity were not recorded at other borehole strain sites along the San Andreas fault...
Effects of seeding procedures and water quality on recovery of Cryptosporidium oocysts from stream water by using U.S. Environmental Protection Agency method 1623
D.S. Francy, O. D. Simmons III, M.W. Ware, E.J. Granger, M.D. Sobsey, F. W. Schaefer III
2004, Applied and Environmental Microbiology (70) 4118-4128
U.S. Environmental Protection Agency method 1623 is widely used to monitor source waters and drinking water supplies for Cryptosporidium oocysts. Matrix spikes, used to determine the effect of the environmental matrix on the method's recovery efficiency for the target organism, require the collection and analysis of two environmental samples, one...
Tracking contaminants down the Mississippi
P. Swarzenski, P. Campbell
2004, Geotimes (49) 40-41
The Mississippi River and its last major downstream distributary, the Atchafalaya River, provide approximately 90 percent of the freshwater input to the Gulf of Mexico. Analyses of sediment cores using organic and inorganic tracers as well as bethic foraminifera appear to provide a reliable record of the historic variability of...
Terrestrial movements of juvenile and adult tailed frogs in relation to timber harvest in coastal British Columbia
Tanya R. Wahbe, Fred L. Bunnell, R. Bruce Bury
2004, Canadian Journal of Forest Research (34) 2455-2466
Tailed frog (Ascaphus truei Stejneger) populations are at risk in much of the Pacific Northwest, and recolonization of sites may be slow postlogging. To examine the terrestrial movements of Ascaphus in clearcuts and old growth, we employed pitfall traps and drift-fence arrays installed along streams and 100 m into upland...
Lattice-Boltzmann simulation of coalescence-driven island coarsening
H. Basagaoglu, C.T. Green, P. Meakin, B.J. McCoy
2004, Journal of Chemical Physics (121) 7987-7995
The first-order phase separation in a thin fluid film was simulated using a two-dimensional lattice-Boltzman model (LBM) with fluid-fluid interactions. The effects of the domain size on the intermediate asymptotic island size distribution were also discussed. It was observed that the overall process is dominated by coalescence which is independent...
Optical characteristics of natural waters protect amphibians from UV-B in the U.S. Pacific Northwest: Reply
Wendy J. Palen, Daniel E. Schindler, M. J. Adams, Christopher A. Pearl, R. Bruce Bury, S. A. Diamond
2004, Ecology (85) 1754-1759
Few ecologists would dispute that exposure to high levels of ultraviolet-B radiation (UV-B) is detrimental to organisms. It is well established that UV-B has been a critical factor shaping the physiology (Blum et al. 1949, Hansson 2000), behavior (Pennington and Emlet 1986, van de Mortel and Buttemer 1998), and distribution (Williamson et...
Annual survival estimation of migratory songbirds confounded by incomplete breeding site-fidelity: Study designs that may help
M.R. Marshall, Duane R. Diefenbach, L.A. Wood, R.J. Cooper
2004, Animal Biodiversity and Conservation (27) 59-72
Many species of bird exhibit varying degrees of site-fidelity to the previous year's territory or breeding area, a phenomenon we refer to as incomplete breeding site-fidelity. If the territory they occupy is located beyond the bounds of the study area or search area (i.e., they have emigrated from the study...
Status of nesting ospreys in coastal Baja California, Sonora, and Sinaloa, Mexico, 1977 and 1992-1993
Charles J. Henny, Daniel W. Anderson
2004, Bulletin, Southern California Academy of Sciences (103) 95-114
No abstract available....
Postfire management in forested public lands of the western USA
R. L. Beschta, J.J. Rhodes, J.B. Kauffman, Robert E. Gresswell, G.W. Minshall, C.A. Frissell, D.A. Perry, R. Hauer
2004, Conservation Biology (18) 957-967
Forest ecosystems in the western United States evolved over many millennia in response to disturbances such as wildfires. Land use and management practices have altered these ecosystems, however, including fire regimes in some areas. Forest ecosystems are especially vulnerable to postfire management practices because such practices may influence forest dynamics...
Estimating tectonic history through basin simulation-enhanced seismic inversion: Geoinformatics for sedimentary basins
K. Tandon, K. Tuncay, K. Hubbard, J. Comer, P. Ortoleva
2004, Geophysical Journal International (156) 129-139
A data assimilation approach is demonstrated whereby seismic inversion is both automated and enhanced using a comprehensive numerical sedimentary basin simulator to study the physics and chemistry of sedimentary basin processes in response to geothermal gradient in much greater detail than previously attempted. The approach not only reduces costs by...
Manatees as sentinels of marine ecosystem health: are they the 2000-pound canaries?
R. K. Bonde, A.A. Aguirre, J. Powell
2004, EcoHealth (1) 255-262
The order Sirenia is represented by three species of manatees and one species of dugong distributed in tropical and subtropical regions of the world and considered vulnerable to extinction. The sentinel species concept is useful to identify indicators of the environment and may reflect the quality of health in marine...
Acidification of forest soil in Russia: From 1893 to present
A.G. Lapenis, G.B. Lawrence, A.A. Andreev, A.A. Bobrov, M.S. Torn, J.W. Harden
2004, Global Biogeochemical Cycles (18)
It is commonly believed that fine-textured soils developed on carbonate parent material are well buffered from possible acidification. There are no data, however, that document resistance of such soils to acidic deposition exposure on a timescale longer than 30-40 years. In this paper, we report on directly testing the long-term...
Sustaining salmonid populations: A caring understanding of naturalness of taxa
Jennifer L. Nielsen, Henry A. Regier
E. Eric Knudsen, editor(s)
2004, Conference Paper, Sustainable management of North American fisheries: American Fisheries Society Symposium 43
Species of the family of Salmonidae occur naturally in Northern Hemisphere waters that remain clear and cool to cold in summer. For purposes of reproduction, salmonids generally behaviorally respond to the currents of streams and lakes in recently glaciated areas. For feeding and maturation, many larger species migrate into existing...
From the Field: Efficacy of visual barriers in reducing black-tailed prairie dog colony expansion
J.W. Merriman, P.J. Zwank, C. W. Boal, T.L. Bashore
2004, Conference Paper, Wildlife Society Bulletin
[No abstract available]...
