Trends and temperature sensitivity of moisture conditions in the conterminous United States
G.J. McCabe, D.M. Wolock
2002, Climate Research (20) 19-29
Observed (1895-1999) trends in climatic moisture conditions in the conterminous United States (US) characterized by (1) annual precipitation minus annual potential evapotranspiration (PMPE), (2) annual surplus (water that eventually becomes streamflow), and (3) annual deficit (the amount of water that must be supplied by irrigation to grow vegetation at an...
Seepage meters and Bernoulli's revenge
E.A. Shinn, C. D. Reich, T.D. Hickey
2002, Estuaries (25) 126-132
Evaluation of seepage data from a network of 50 permanently deployed submarine seepage meters, specially constructed from fiberglass, indicates that the devices artificially advect (Bernoulli effect) shallow ground water. Reverse flow into the rock was not observed even when adjacent piezometers installed 2-m to 20-m below the rock-water interface indicated...
Tracing sources of sulfur in the Florida Everglades
A. L. Bates, W. H. Orem, J. W. Harvey, E.C. Spiker
2002, Journal of Environmental Quality (31) 287-299
We examined concentrations and sulfur isotopic ratios (34S/32S, expressed as δ34S in parts per thousand [‰] units) of sulfate in surface water, ground water, and rain water from sites throughout the northern Everglades to establish the sources of sulfur to the ecosystem. The geochemistry of sulfur is of particular interest...
Primary modes and predictability of year-to-year snowpack variations in the Western United States from teleconnections with Pacific Ocean climate
G.J. McCabe, M. D. Dettinger
2002, Journal of Hydrometeorology (3) 13-25
Snowpack, as measured on 1 April, is the primary source of warm-season streamflow for most of the western United States and thus represents an important source of water supply. An understanding of climate factors that influence the variability of this water supply and thus its predictability is important for water...
Upgraded gravity anomaly base of the United States
Gordon R. Keller, T.G. Hildenbrand, Robert Kucks, D. Roman, A. M. Hittelman
2002, The Leading Edge (21) 366-367
A concerted effort to compile an upgraded gravity anomaly database, grid, and map for the United States by the end of 2002 is under way. This effort can be considered as the first step in building a data system for gravity measurements, and it builds on existing collaborative efforts. This...
Provincial variation of carbon emissions from bituminous coal: Influence of inertinite and other factors
J.C. Quick, T. Brill
2002, International Journal of Coal Geology (49) 263-275
We observe a 1.3 kg C/net GJ variation of carbon emissions due to inertinite abundance in some commercially available bituminous coal. An additional 0.9 kg C/net GJ variation of carbon emissions is expected due to the extent of coalification through the bituminous rank stages. Each percentage of sulfur in bituminous...
Source water partitioning as a means of characterizing hydrologic function in mangroves
J.Z. Drexler, E. W. De Carlo
2002, Wetlands Ecology and Management (10) 103-113
Mangrove ecosystems rely on seawater, rain-derived flow, and groundwater for hydrologic sustenance, flushing, and inflow of nutrients and sediments. The relative contribution of these source waters and their variability through time and space can provide key information concerning the hydrologic function of ecosystems. We used hydrologic tracers to partition source...
Identification of lithofacies using Kohonen self-organizing maps
H.-C. Chang, D. C. Kopaska-Merkel, H.-C. Chen
2002, Computers & Geosciences (28) 223-229
Lithofacies identification is a primary task in reservoir characterization. Traditional techniques of lithofacies identification from core data are costly, and it is difficult to extrapolate to non-cored wells. We present a low-cost automated technique using Kohonen self-organizing maps (SOMs) to identify systematically and objectively lithofacies from well log data. SOMs...
Source properties of earthquakes near the Salton Sea triggered by the 16 October 1999 M 7.1 Hector Mine, California, earthquake
S. E. Hough, H. Kanamori
2002, Bulletin of the Seismological Society of America (92) 1281-1289
We analyze the source properties of a sequence of triggered earthquakes that occurred near the Salton Sea in southern California in the immediate aftermath of the M 7.1 Hector Mine earthquake of 16 October 1999. The sequence produced a number of early events that were not initially located by the...
Selenium biotransformations into proteinaceous forms by foodweb organisms of selenium-laden drainage waters in California
J.E. Spallholz, D. J. Hoffman
2002, Aquatic Toxicology (57) 65-84
Selenium contamination represents one of the few clear cases where environmental pollution has led to devastation of wildlife populations, most notably in agricultural drainage evaporation and power plant coal-fly ash receiving ponds. Complex biogeochemistry, in particular extensive biotransformations and foodchain transfer, governs Se ecotoxicology and toxicology, for which the mechanism(s)...
Atrazine and metolachlor occurrence in shallow ground water of the United States, 1993 to 1995: Relations to explanatory factors
D.W. Kolpin, J.E. Barbash, R. J. Gilliom
2002, Journal of the American Water Resources Association (38) 301-311
Since 1991, the U.S. Geological Survey has been conducting the National Water Quality Assessment (NAWQA) Program to determine the quality of the Nation's water resources. In an effort to obtain a better understanding of why pesticides are found in shallow ground water on a national scale, a set of factors...
Identifying elements of the plumbing system beneath Kilauea Volcano, Hawaii, from the source locations of very-long-period signals
J. Almendros, B. Chouet, P. Dawson, T. Bond
2002, Geophysical Journal International (148) 303-312
We analyzed 16 seismic events recorded by the Hawaiian broad-band seismic network at Kilauca Volcano during the period September 9-26, 1999. Two distinct types of event are identified based on their spectral content, very-long-period (VLP) waveform, amplitude decay pattern and particle motion. We locate the VLP signals with a method...
Uranium-series dating of pedogenic silica and carbonate, Crater Flat, Nevada
K.R. Ludwig, J.B. Paces
2002, Geochimica et Cosmochimica Acta (66) 487-506
A 230Th-234U-238U dating study on pedogenic silica-carbonate clast rinds and matrix laminae from alluvium in Crater Flat, Nevada was conducted using small-sample thermal-ionization mass spectrometry (TIMS) analyses on a large suite of samples. Though the 232Th content of these soils is not particularly low (mostly 0.1-9 ppm), the high U...
Displaced rocks, strong motion, and the mechanics of shallow faulting associated with the 1999 Hector Mine, California, earthquake
Andrew J. Michael, Stephanie L. Ross, Heidi D. Stenner
2002, Bulletin of the Seismological Society of America (92) 1561-1569
The paucity of strong-motion stations near the 1999 Hector Mine earthquake makes it impossible to make instrumental studies of key questions about near-fault strong-motion patterns associated with this event. However, observations of displaced rocks allow a qualitative investigation of these problems. By observing the slope of the desert surface and...
Moment-tensor solutions estimated using optimal filter theory: Global seismicity, 2000
S.A. Sipkin, C. G. Bufe, M.D. Zirbes
2002, Physics of the Earth and Planetary Interiors (130) 129-142
Moment-tensor solutions, estimated using optimal filter theory, are listed for 324 moderate-to-large size earthquakes that occurred during the year 2000. Published by Elsevier Science B.V....
Effect of growth conditions and staining procedure upon the subsurface transport and attachment behaviors of a groundwater protist
R.W. Harvey, N. Mayberry, N.E. Kinner, D.W. Metge, F. Novarino
2002, Applied and Environmental Microbiology (68) 1872-1881
The transport and attachment behaviors of Spumella guttula (Kent), a nanoflagellate (protist) found in contaminated and uncontaminated aquifer sediments in Cape Cod, Mass., were assessed in flowthrough and static columns and in a field injection-and-recovery transport experiment involving an array of multilevel samplers. Transport of S. guttula harvested from low-nutrient...
Effects of disturbance on germination and seedling establishment in a coastal prairie grassland: A test of the competitive release hypothesis
H.M. Jutila, J.B. Grace
2002, Journal of Ecology (90) 291-302
1. We evaluated the responses of native grassland sods to a variety of types of disturbance in order to assess hypotheses about the competitive effects of established vegetation on seed germination and seedling establishment. In particular, we consider whether germination is more responsive to the magnitude and duration of vegetation...
The shaping of continental slopes by internal tides
D.A. Cacchione, Lincoln F. Pratson, A.S. Ogston
2002, Science (296) 724-727
The angles of energy propagation of semidiurnal internal tides may determine the average gradient of continental slopes in ocean basins (???2 to 4 degrees). Intensification of near-bottom water velocities and bottom shear stresses caused by reflection of semi-diurnal internal tides affects sedimentation patterns and bottom gradients, as indicated by recent...
Tectonics and distribution of gold deposits in China - An overview
T. Zhou, Richard J. Goldfarb, Neil G. Phillips
2002, Mineralium Deposita (37) 249-282
Gold exploration in China has expanded rapidly during the last two decades since a modern approach to economic development has become a national priority. China currently produces 180 tonnes (t) of gold annually, which is still significantly less than South Africa, USA, and Australia. However, China is now recognized as possessing...
Control of strong ground motion of mining-induced earthquakes by the strength of the seismogenic rock mass
Art McGarr
2002, Journal of the South African Institute of Mining and Metallurgy (102) 225-229
The shear stress ?? that can be sustained by the rock mass in the environs of a mining-induced earthquake controls the near-fault peak ground velocity v of that event according to v???0.25(??/G) ??, where ?? is the shear wave speed and G is the modulus of rigidity. To estimate ??...
Long-term climate patterns in Alaskan surface temperature and precipitation and their biological consequences
James J. Simpson, Gary L. Hufford, Michael D. Fleming, Jared S. Berg, J.B. Ashton
2002, IEEE Transactions on Geoscience and Remote Sensing (40) 1164-1184
Mean monthly climate maps of Alaskan surface temperature and precipitation produced by the parameter-elevation regression on independent slopes model (PRISM) were analyzed. Alaska is divided into interior and coastal zones with consistent but different climatic variability separated by a transition region; it has maximum interannual variability but low long-term mean...
Prioritizing conservation potential of arid-land montane natural springs and associated riparian areas
B.C. Thompson, P. L. Matusik-Rowan, K.G. Boykin
2002, Journal of Arid Environments (50) 527-547
Using inventory data and input from natural resource professionals, we developed a classification system that categorizes conservation potential for montane natural springs. This system contains 18 classes based on the presence of a riparian patch, wetland species, surface water, and evidence of human activity. We measured physical and biological components...
Differential use of a Wolf, Canis lupus, pack territory edge and core
L.D. Mech, E. K. Harper
2002, Canadian Field-Naturalist (116) 315-316
Based on 418 radio-locations of a Minnesota Wolf pack, Wolves were found at significantly fewer locations per area in the outer 2 km of the territory than in the core. This finding supports an hypothesis that buffer zones exist between pack territories and may explain why prey survive longer there....
Salt deposits in Arizona promise gas-storage opportunities
S.L. Rauzi
2002, Oil & Gas Journal (100) 68-70
Massive salt formations and their proximity to pipeline systems and power plants make Arizona attractive for natural gas storage. Caverns dissolved in subsurface salt are used to store LPG at Ferrellgas Partners LP facility near Holbrook and the AmeriGas Partners LP facility near Glendale. Three other companies are investigating the...
Factors regulating nitrification in aquatic sediments: Effects of organic carbon, nitrogen availability, and pH
E.A. Strauss, N.L. Mitchell, G. A. Lamberti
2002, Canadian Journal of Fisheries and Aquatic Sciences (59) 554-563
We investigated the response in nitrification to organic carbon (C) availability, the interactive effects of the C: nitrogen (N) ratio and organic N availability, and differing pH in sediments from several streams in the upper midwestern United States. In addition, we surveyed 36 streams to assess variability in sediment nitrification...
