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Page 2731, results 68251 - 68275

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Publication Extents

Not all publications have extents, not all extents are completely accurate
Reconciling different observations of the CO2 ice mass loading of the Martian north polar cap
Robert M. Haberle, Bridget Mattingly, Timothy N. Titus
2004, Geophysical Research Letters (31)
The GRS measurements of the peak mass loading of the north polar CO2 ice cap on Mars are about 60% lower than those calculated from MGS TES radiation data and those inferred from the MOLA cap thicknesses. However, the GRS data provide the most accurate measurement of the mass loading. We...
A Complex Systems Model Approach to Quantified Mineral Resource Appraisal
M. E. Gettings, M.W. Bultman, F. S. Fisher
2004, Environmental Management (33) 87-98
For federal and state land management agencies, mineral resource appraisal has evolved from value-based to outcome-based procedures wherein the consequences of resource development are compared with those of other management options. Complex systems modeling is proposed as a general framework in which to build models that can evaluate outcomes. Three...
Specific conductance and water temperature data for San Francisco Bay, California, for Water Year 2003
P.A. Buchanan
2004, Interagency Ecological Program Newsletter (17) 11-14
This article presents time-series graphs of specific-conductance and water-temperature data collected in San Francisco Bay during water year 2003 (October 1, 2002, through September 30, 2003). Specific-conductance and water-temperature data were recorded at 15-minute intervals at the following US Geological Survey (USGS) locations (Figure 1): • Suisun Bay at Benicia...
Unusual behavior by Bison, Bison bison, toward Elk, Cervus elaphus, and wolves, Canis lupus
L.D. Mech, R.T. McIntyre, D.W. Smith
2004, Canadian Field-Naturalist (118) 115-118
Incidents are described of Bison (Bison bison) in Yellowstone National Park mauling and possibly killing a young Elk (Cervus elaphus) calf, chasing wolves (Canis lupus) off Elk they had just killed or were killing, and keeping the wolves away for extended periods. During one of the latter cases, the Bison...
Transient Analysis of the Source of Water to Wells: Cape Cod, Massachusetts
John P. Masterson, D. A. Walter, D.R. LeBlanc
2004, Ground Water (42) 126-134
A transient flow modeling analysis for potential public-supply wells on western Cape Cod, Massachusetts, demonstrates the difference between transient and steady-state recharge areas can have important implications for wellhead protection. An example of a single pumping well illustrates that commonly, used steady-state time-related capture areas do not represent the recharge...
Bighorn sheep habitat studies, population dynamics, and population modeling in Bighorn Canyon National Recreation Area, Wyoming and Montana, 2000-2003
Francis J. Singer, Kathryn A. Schoenecker
2004, Open-File Report 2004-1337
At the request of National Park Service resource managers, we began a study in 2000 to evaluate causes for the decline of the bighorn sheep (Ovis canadensis) population inhabiting Bighorn Canyon National Recreation Area (BICA), the Pryor Mountain Wild Horse Range, and surrounding state and U.S. Forest Service lands in...
Numerical study of electromagnetic waves generated by a prototype dielectric logging tool
K.J. Ellefsen, J.D. Abraham, D.L. Wright, A.T. Mazzella
2004, Geophysics (69) 64-77
To understand the electromagnetic waves generated by a prototype dielectric logging tool, a numerical study was conducted using both the finite-difference, time-domain method and a frequency-wavenumber method. When the propagation velocity in the borehole was greater than that in the formation (e.g., an air-filled borehole in the unsaturated zone), only...
Fort Collins Science Center: Invasive Species Science
Tom Stohlgren
2004, Fact Sheet 2004-3145
Invasive, non-native species of plants, animals, and disease organisms adversely affect the ecosystems they enter. Like "biological wildfires," they can quickly spread, and they affect nearly all terrestrial and aquatic ecosystems. Invasive species have become the greatest environmental challenge of the 21st century in terms of economic, environmental, and human...
Water year 2004: Western water managers feel the heat
Thomas Pagano, Phil Pasteris, Michael D. Dettinger, Daniel Cayan, Kelly Redmond
2004, Eos, Earth and Space Science News (85) 385-393
This spring, a rare combination of exceptionally warm temperatures and near-record lack of precipitation in the western United States caused a rapid change in hydrologic conditions and an unexpectedly early onset of spring conditions. With much of the western U.S. already in its fifth year of drought, an above-average western snowpack...
Early environment and recruitment of black brant (Branta bernicla nigricans) into the breeding population
James S. Sedinger, Mark P. Herzog, David H. Ward
2004, The Auk (121) 68-73
In geese, growth regulates survival in the first year. We examined whether early growth, which is primarily governed by environmental conditions, also affects the probability that individuals that survive their first year enter the breeding population. We used logistic regression on a sample of Black Brant (Branta bernicla nigricans) that...
Geophysical data reveal the crustal structure of the Alaska Range orogen within the aftershock zone of the Mw 7.9 Denali fault earthquake
M. A. Fisher, N. A. Ratchkovski, W. J. Nokleberg, L. Pellerin, J.M.G. Glen
2004, Bulletin of the Seismological Society of America (94) S107-S131
Geophysical information, including deep-crustal seismic reflection, magnetotelluric (MT), gravity, and magnetic data, cross the aftershock zone of the 3 November 2002 Mw 7.9 Denali fault earthquake. These data and aftershock seismicity, jointly interpreted, reveal the crustal structure of the right-lateral-slip Denali fault and the eastern Alaska Range orogen, as well...
The microbial arsenic cycle in Mono Lake, California
Ronald S. Oremland, John F. Stolz, James T. Hollibaugh
2004, FEMS Microbiology Ecology (48) 15-27
Significant concentrations of dissolved inorganic arsenic can be found in the waters of a number of lakes located in the western USA and in other water bodies around the world. These lakes are often situated in arid, volcanic terrain. The highest concentrations of arsenic occur in hypersaline, closed basin soda...
Comparison of geodetic and glaciological mass-balance techniques, Gulkana Glacier, Alaska, U.S.A
L.H. Cox, R.S. March
2004, Journal of Glaciology (50) 363-370
The net mass balance on Gulkana Glacier, Alaska, U.S.A., has been measured since 1966 by the glaciological method, in which seasonal balances are measured at three index sites and extrapolated over large areas of the glacier. Systematic errors can accumulate linearly with time in this method. Therefore, the geodetic balance,...
The opportunity Rover's Athena science investigation at Meridiani Planum, Mars
S. W. Squyres, R. E. Arvidson, J.F. Bell III, J. Bruckner, N.A. Cabrol, W. Calvin, M. H. Carr, P. R. Christensen, B. C. Clark, L. Crumpler, D.J. Des Marais, C. D'Uston, T. Economou, J. Farmer, W. Farrand, W. Folkner, M. Golombek, S. Gorevan, J. A. Grant, R. Greeley, J. Grotzinger, L. Haskin, Kenneth E. Herkenhoff, S. Hviid, J. Johnson, G. Klingelhofer, A.H. Knoll, G. Landis, M. Lemmon, R. Li, M.B. Madsen, M. C. Malin, S. M. McLennan, H.Y. McSween, D. W. Ming, J. Moersch, R.V. Morris, T. Parker, J. W. Rice Jr., L. Richter, R. Rieder, M. Sims, M. Smith, P. Smith, Laurence A. Soderblom, R. Sullivan, H. Wanke, T. Wdowiak, M. Wolff, A. Yen
2004, Science (306) 1698-1703
The Mars Exploration Rover Opportunity has investigated the landing site in Eagle crater and the nearby plains within Meridiani Planum. The soils consist of fine-grained basaltic sand and a surface lag of hematite-rich spherules, spherule fragments, and other granules. Wind ripples are common. Underlying the thin soil layer, and exposed...
Numerical simulations of large earthquakes: Dynamic rupture propagation on heterogeneous faults
R.A. Harris
2004, Pure and Applied Geophysics (161) 2171-2181
Our current conceptions of earthquake rupture dynamics, especially for large earthquakes, require knowledge of the geometry of the faults involved in the rupture, the material properties of the rocks surrounding the faults, the initial state of stress on the faults, and a constitutive formulation that determines when the faults can...
Variability of hydrologic regimes and morphology in constructed open-ditch channels
J.S. Strock, J.A. Magner, W. B. Richardson, M.J. Sadowsky, G.R. Sands, R.T. Venterea
Cooke R.A., editor(s)
2004, Conference Paper, Proceedings of the 8th International Drainage Symposium - Drainage VIII
Open-ditch ecosystems are potential transporters of considerable loads of nutrients, sediment, pathogens and pesticides from direct inflow from agricultural land to small streams and larger rivers. Our objective was to compare hydrology and channel morphology between two experimental open-ditch channels. An open-ditch research facility incorporating a paired design was constructed...
Dynamic rupture modeling of the transition from thrust to strike-slip motion in the 2002 Denali fault earthquake, Alaska
Brad T. Aagaard, G. Anderson, K.W. Hudnut
2004, Bulletin of the Seismological Society of America (94) S190-S201
We use three-dimensional dynamic (spontaneous) rupture models to investigate the nearly simultaneous ruptures of the Susitna Glacier thrust fault and the Denali strike-slip fault. With the 1957 Mw 8.3 Gobi-Altay, Mongolia, earthquake as the only other well-documented case of significant, nearly simultaneous rupture of both thrust and strike-slip faults, this...