Flow distribution in selected branches of St. Clair and Detroit rivers
David J. Holtschlag, John A. Koschik
2002, Journal of Great Lakes Research (28) 379-395
St. Clair and Detroit rivers, which are connecting channels between Lake Huron and Lake Erie in the Great Lakes basin, form part of the boundary between the state of Michigan and the province of Ontario. In 13 reaches, this flow divides locally around islands and dikes to form 31 branches....
Relations between soil moisture and satellite vegetation indices in the U.S. Corn Belt
Jimmy O. Adegoke, A.M. Carleton
2002, Journal of Hydrometeorology (3) 395-405
Satellite-derived vegetation indices extracted over locations representative of midwestern U.S. cropland and forest for the period 1990–94 are analyzed to determine the sensitivity of the indices to neutron probe soil moisture measurements of the Illinois Climate Network (ICN). The deseasoned (i.e., departures from multiyear mean annual cycle) soil moisture measurements...
Bedform movement recorded by sequential single-beam surveys in tidal rivers
R.L. Dinehart
2002, Journal of Hydrology (258) 25-39
A portable system for bedform-mapping was evaluated in the delta of the lower Sacramento and San Joaquin Rivers, California, from 1998 to 2000. Bedform profiles were surveyed with a two-person crew using an array of four single-beam transducers on boats about 6 m in length. Methods for processing the bedform...
Strike-slip earthquakes in the oceanic lithosphere: Observations of exceptionally high apparent stress
George Choy, Art McGarr
2002, Geophysical Journal International (150) 506-523
The radiated energies, ES, and seismic moments, M0, for 942 globally distributed earthquakes that occurred between 1987 to 1998 are examined to find the earthquakes with the highest apparent stresses (τa=μES/M0, where μ is the modulus of rigidity). The globally averaged τa for shallow earthquakes in all tectonic environments and seismic regions is...
Related magma-ice interactions: Possible origins of chasmata, chaos, and surface materials in Xanthe, Margaritifer, Meridiani Terrae, Mars
M. G. Chapman, K. L. Tanaka
2002, Icarus (155) 324-339
We examine here the close spatial and temporal associations among several unique features of Xanthe and Margaritifer Terrae, specifically the Valles Marineris troughs or chasmata and their interior deposits, chaotic terrain, the circum-Chryse outflow channels, and the subdued cratered material that covers Xanthe, Margaritifer, and Meridiani Terrae. Though previous hypotheses...
Optimal exploitation of spatially distributed trophic resources and population stability
A. Basset, M. Fedele, D.L. DeAngelis
2002, Ecological Modelling (151) 245-260
The relationships between optimal foraging of individuals and population stability are addressed by testing, with a spatially explicit model, the effect of patch departure behaviour on individual energetics and population stability. A factorial experimental design was used to analyse the relevance of the behavioural factor in relation to three factors...
The dynamics of subtidal poleward flows over a narrow continental shelf, Palos Verdes, CA
M.A. Noble, H. F. Ryan, P.L. Wiberg
2002, Continental Shelf Research (22) 923-944
The Palos Verdes peninsula is a short, very narrow (< 3 km) shelf in southern California that is bracketed by two large embayments. In May 1992, arrays of up to 4 moorings and 2 benthic tripods were deployed in a yearlong study of the circulation processes over this shelf and...
Organochlorine chemical residues in fish from the Mississippi River basin, 1995
C. J. Schmitt
2002, Archives of Environmental Contamination and Toxicology (43) 81-97
Fish were collected in late 1995 from 34 National Contaminant Biomonitoring Program (NCBP) stations and 13 National Water Quality Assessment Program (NAWQA) stations in the Mississippi River basin (MRB) and in late 1996 from a reference site in West Virginia. Four composite samples, each comprising (nominally) 10 adult common carp...
δ13C of low-molecular-weight organic acids generated by the hydrous pyrolysis of oil-prone source rocks
Robert F. Dias, Katherine H. Freeman, Michael D. Lewan, Stephen G. Franks
2002, Geochimica et Cosmochimica Acta (66) 2755-2769
Low-molecular-weight (LMW) aqueous organic acids were generated from six oil-prone source rocks under hydrous-pyrolysis conditions. Differences in total organic carbon–normalized acid generation are a function of the initial thermal maturity of the source rock and the oxygen content of the kerogen (OI). Carbon-isotope analyses were...
Predation on exotic zebra mussels by native fishes: Effects on predator and prey
D.D. Magoulick, L.C. Lewis
2002, Freshwater Biology (47) 1908-1918
1. Exotic zebra mussels, Dreissena polymorpha, occur in southern U.S. waterways in high densities, but little is known about the interaction between native fish predators and zebra mussels. Previous studies have suggested that exotic zebra mussels are low profitability prey items and native vertebrate predators are unlikely to reduce zebra...
Prioritizing High-Temperature Geothermal Resources in Utah
R.E. Blackett, T.C. Brill, G.M. Sowards
2002, Conference Paper, Transactions - Geothermal Resources Council
The Utah Geological Survey and the Utah Energy Office recently released geothermal resource information for Utah as a "digital atlas." We are now expanding this project to include economic analyses of selected geothermal sites and previously unavailable resource information. The enhancements to the digital atlas will include new resource, demographic,...
Depositional history and neotectonics in Great Salt Lake, Utah, from high-resolution seismic stratigraphy
Steven M. Colman, K.R. Kelts, David A. Dinter
2002, Sedimentary Geology (148) 61-78
High-resolution seismic-reflection data from Great Salt Lake show that the basinal sediment sequence is cut by numerous faults with N-S and NE-SW orientations. This faulting shows evidence of varied timing and relative offsets, but includes at least three events totaling about 12 m following the Bonneville phase of the lake...
Effect of deer exclusion by fencing on abundance of Amblyomma americanum (Acari: Ixodidae) on Fire Island, New York, USA
H. S. Ginsberg, M. Butler, E. Zhioua
2002, Journal of Vector Ecology (27) 215-221
The effects of deer exclusion on northern populations of lone star ticks, Amblyomma americanum, were tested at the Lighthouse Tract, Fire Island, NY, USA, where densities of this species have increased recently. Game fencing was erected to exclude deer from two sites of roughly one ha each, and populations of...
Increased selenium threat as a result of invasion of the exotic bivalve Potamocorbula amurensis into the San Francisco Bay-Delta
R.G. Linville, S. N. Luoma, L. Cutter, G.A. Cutter
2002, Aquatic Toxicology (57) 51-64
Following the aggressive invasion of the bivalve, Potamocorbula amurensis, in the San Francisco Bay-Delta in 1986, selenium contamination in the benthic food web increased. Concentrations in this dominant (exotic) bivalve in North Bay were three times higher in 1995–1997 than in earlier studies, and 1990...
A budget of marine and terrigenous sediments, Hanalei Bay, Kauai, Hawaiian Islands
R.S. Calhoun, C. H. Fletcher, J.N. Harney
2002, Sedimentary Geology (150) 61-87
The sediment budget of Hanalei Bay on the north shore of Kauai was calculated using sedimentological and geophysical methods. The calculations of the budget subsequently allowed an interpretation of the Holocene history of the bay. The bay sediments are easily separated into marine (carbonate) and terrigenous (siliciclastic) grains. Surficial sediments...
A comparison of diets of blueback herring (Alosa aestivalis) and threadfin shad (Dorosoma petenense) in a large southeastern U.S. Reservoir
Dana L. Winkelman, Michael J. Van Den Avyle
2002, Journal of Freshwater Ecology (17) 209-221
The objective of this study was to determine dietary overlap between blueback herring and threadfin shad in J. Strom Thrumond Reservoir, South Carolina/Georgia. We also evaluated prey selectivity for each speices and diet differences between two size categories of blueback herring. Diet and zooplankton samples were collected every other month...
Long-term tritium transport through field-scale compacted soil liner
C. Toupiol, T.W. Willingham, A.J. Valocchi, C.J. Werth, I.G. Krapac, T.D. Stark, D.E. Daniel
2002, Journal of Geotechnical and Geoenvironmental Engineering (128) 640-650
A 13-year study of tritium transport through a field-scale earthen liner was conducted by the Illinois State Geological Survey to determine the long-term performance of compacted soil liners in limiting chemical transport. Two field-sampling procedures (pressure-vacuum lysimeter and core sampling) were used to determine the vertical tritium concentration profiles at...
Porometric properties of siliciclastic marine sand: A comparison of traditional laboratory measurements with image analysis and effective medium modeling
A.H. Reed, K.B. Briggs, D. L. Lavoie
2002, IEEE Journal of Oceanic Engineering (27) 581-592
During the 1999 sediment acoustics experiment (SAX99), porometric properties were measured and predicted for a well sorted, medium sand using standard laboratory geotechnical methods and image analysis of resin-impregnated sediments. Sediment porosity measured by laboratory water-weight-loss methods (0.372 ?? 0.0073 for mean ??1 standard deviation) is 0.026 lower than determined...
The oligocene Lund Tuff, Great Basin, USA: A very large volume monotonous intermediate
L.L. Maughan, E. H. Christiansen, M. G. Best, C. S. Grommé, A.L. Deino, D.G. Tingey
2002, Journal of Volcanology and Geothermal Research (113) 129-157
Unusual monotonous intermediate ignimbrites consist of phenocryst-rich dacite that occurs as very large volume (> 1000 km3) deposits that lack systematic compositional zonation, comagmatic rhyolite precursors, and underlying plinian beds. They are distinct from countless, usually smaller volume, zoned rhyolite-dacite-andesite deposits that are conventionally believed to have erupted from magma...
Assessing browse trend at the landscape level Part 1: Preliminary steps and field survey
R.B. Keigley, M.R. Frisina, C.W. Fager
2002, Rangelands (24) 28-33
Woody plants are an important component of rangeland habitat, providing food and shelter for animals that range in size from moose to warblers to insects. Because of this importance, land managers are paying increased attention to browse trends. In this two-part article, we describe how browse trend is assessed at...
Late quaternary evolution of the Orinoco Delta, Venezuela
A.G. Warne, E.H. Guevara, A. Aslan
2002, Journal of Coastal Research (18) 225-253
The modern Orinoco Delta is the latest of a series of stacked deltas that have infilled the Eastern Venezuelan Basin (EVB) since the Oligocene. During the late Pleistocene sea-level lowstand (20,000 to 16,000 yrs BP), bedrock control points at the position of the present delta apex prevented the river channel...
Nestling sex ratios in the southwestern willow flycatcher
Eben H. Paxton, Mark K. Sogge, Tracy McCarthey, Paul Keim
2002, Condor (104) 877-881
Using molecular-genetic techniques, we determined the gender of 202 Southwestern Willow Flycatcher (Empidonax traillii extimus) nestlings from 95 nests sampled over a five-year period. Overall nestling sex ratio did not vary significantly from 50:50 among years, by clutch order, or by mating strategy (monogamous vs. polygamous pairings). However, we did...
Place vs. time and vegetational persistence: A comparison of four tropical mires from the Illinois Basin during the height of the Pennsylvanian Ice Age
William A. DiMichele, T.L. Phillips, W. John Nelson
2002, International Journal of Coal Geology (50) 43-72
Coal balls were collected from four coal beds in the southeastern part of the Illinois Basin. Collections were made from the Springfield, Herrin, and Baker coals in western Kentucky, and from the Danville Coal in southwestern Indiana. These four coal beds are among the principal mineable coals of the Illinois...
Development and evaluation of a local grid refinement method for block-centered finite-difference groundwater models using shared nodes
S. Mehl, M. C. Hill
2002, Advances in Water Resources (25) 497-511
A new method of local grid refinement for two-dimensional block-centered finite-difference meshes is presented in the context of steady-state groundwater-flow modeling. The method uses an iteration-based feedback with shared nodes to couple two separate grids. The new method is evaluated by comparison with results using a uniform fine mesh, a...
Subsurface fluid pressures from drill-stem tests, Uinta Basin, Utah
P. H. Nelson
2002, Mountain Geologist (39) 17-26
High fluid pressures are known to be associated with oil and gas fields in the Uinta Basin, Utah. Shut-in pressure measurements from drill-stem tests show how pressure varies with depth and by area within the basin. The data base used in this report incorporates over 2,000 pressure measurements from drill-stem...
