Water erosion on mars and its biologic implications
M. H. Carr
1996, Endeavour (20) 56-60
The Martian surface shows abundant evidence of water erosion. Liquid water is unstable under present climatic conditions but conditions may have been different in the past. The planet has been volcanically active throughout its history. The combination of water and volcanism must have commonly resulted in hydrothermal environments similar to...
Relation of landscape position and irrigation to concentrations of alachlor, atrazine, and selected degradates in regolith in northeastern Nebraska
Ingrid M. Verstraeten, D. T. Lewis, D. L. McCallister, A. Parkhurst, E.M. Thurman
1996, ACS Symposium Series (630) 178-197
Concentrations of alachlor, its ethanesulfonic acid degradate, atrazine and its degradates, deethylatrazine and deisopropylatrazine, in the upper regolith and associated shallow aquifers were determined in relation to landscape position (floodplains, terraces, and uplands) and irrigation (nonirrigated and irrigated corn cropland) in 1992. Irrigated and nonirrigated sites were located on each...
Deicing chemicals as source of constituents of highway runoff
G.E. Granato
1996, Transportation Research Record (1533) 50-58
The dissolved major and trace constituents of deicing chemicals as a source of constituents in highway runoff must be quantified for interpretive studies of highway runoff and its effects on surface water and groundwater. Dissolved constituents of the deicing chemicals—sodium chloride, calcium chloride, and premix (a mixture of sodium and...
Volcanic hazards and aviation safety
Thomas J. Casadevall, Theodore B. Thompson, John W. Ewert
Housner G.W.Chung R.M., editor(s)
1996, Conference Paper, Proceedings of the Conference on Natural Disaster Reduction
An aeronautical chart was developed to determine the relative proximity of volcanoes or ash clouds to the airports and flight corridors that may be affected by volcanic debris. The map aims to inform and increase awareness about the close spatial relationship between volcanoes and aviation operations. It shows the locations...
Appalachian piedmont regolith: Relations of saprolite and residual soils to rock-type
M.J. Pavich
1996, Geotechnical Special Publication
Saprolite is a major product of rock weathering on the Appalachian Piedmont from New Jersey to Alabama. On the Piedmont, it is the primary substrate from which residual soils are developed. Properties of saprolite and residual soils are highly related to their parent rocks. Studies of cores and outcrops illustrate...
Exsolved magmatic fluid and its role in the formation of comb-layered quartz at the Cretaceous Logtung W-Mo deposit, Yukon Territory, Canada
J. B. Lowenstern, W.D. Sinclair
1996, Transactions of the Royal Society of Edinburgh, Earth Sciences (87) 291-303
Comb-layered quartz is a type of unidirectional solidification texture found at the roofs of shallow silicic intrusions that are often associated spatially with Mo and W mineralisation. The texture consists of multiple layers of euhedral, prismatic quartz crystals (Type I) that have grown on subplanar aplite substrates. The layers are...
Geology and geothermal potential of Alid volcanic center, Eritrea, Africa
Michael A. Clynne, Wendell A. Duffield, Robert O. Fournier, Leake W. Giorgis, Cathy J. Janik, Gabreab Kahsai, Jacob Lowenstern, Kidane W. Mariam, James G. Smith, Theoderos Tesfai
Anon, editor(s)
1996, Conference Paper, Transactions - Geothermal Resources Council
Alid volcanic center, a 700-meter-tall mountain in Eritrea, northeast Africa, straddles the axis of an active crustal-spreading center called the Danakil Depression. Boiling-temperature fumaroles are common on Alid, and their gas compositions indicate a reservoir temperature of at least 250 ??C. The history of volcanism and the high reservoir temperature...
Disinfection byproduct yields from the chlorination of natural waters
R. E. Rathbun
1996, Archives of Environmental Contamination and Toxicology (31) 420-425
Yields for the formation of trihalomethane and nonpurgeable total organic-halide disinfection byproducts were determined as a function of pH and initial free-chlorine concentration for the chlorination of water from the Mississippi, Missouri, and Ohio Rivers. Samples were collected at 12 sites on the Mississippi River from Minneapolis, MN, to New...
Nitrogen transport from tallgrass prairie watersheds
W. K. Dodds, J.M. Blair, G.M. Henebry, J.K. Koelliker, R. Ramundo, C. M. Tate
1996, Conference Paper, Journal of Environmental Quality
Discharge and N content of surface water flowing from four Karat watersheds on Konza Prairie Research Natural Area, Kansas, managed with different burn frequencies, were monitored from 1986 to 1992. The goal was to establish the influence of natural processes (climate, fire, and bison grazing) on N transport and concentration...
Stability of hydrous phases in subducting oceanic crust
J. Liu, S.R. Bohlen, W. G. Ernst
1996, Earth and Planetary Science Letters (143) 161-171
Experiments in the basalt-H2O system at 600–950°C and 0.8–3.0 GPa, demonstrate that breakdown of amphibole represents the final dehydration of subducting oceanic tholeiite at T≥650°C; the dehydration H2O occurs as a free fluid or in silicate melt co-existing with an anhydrous eclogite assemblage....
Paleomagnetism of Jurassic radiolarian chert above the Coast Range ophiolite at Stanley Mountain, California, and implications for its paleogeographic origins
J.T. Hagstrum, B.L. Murchey
1996, Geological Society of America Bulletin (108) 643-652
Upper Jurassic red tuffaceous chert above the Coast Range ophiolite at Stanley Mountain, California (lat 35°N, long 240°E), contains three components of remanent magnetization. The first component (A; removed by ≈100–≈200°C) has a direction near the present-day field for southern California and is...
Pb and O isotopic constraints on the source of granitic rocks from Cape Breton Island, Nova Scotia, Canada
Robert A. Ayuso, S. M. Barr, Frederick J. Longstaffe
1996, American Journal of Science (296) 789-817
Pb isotopic compositions of leached feldspars from twenty-three plutons in Cape Breton Island can be divided into two groups: anorthosite, syenite, and granite in the Blair River Complex, which have the least radiogenic compositions on the Island, and granitic rocks from terranes (Aspy, Bras d'Or, and Mira) to the south....
Temperature and the seismic/aseismic transition: Observations from the 1992 Landers earthquake
C.F. Williams
1996, Geophysical Research Letters (23) 2029-2032
An important constraint on the size and destructive potential of earthquakes is the depth extent of rupture. Laboratory studies of the transition from unstable to stable sliding, along with ob served relationships between surface heat flow and the thickness of the seismogenic crust, provide strong evidence for the significance of...
Pesticides and pesticide degradation products in stormwater runoff: Sacramento River Basin, California
Joseph L. Domagalski
1996, Water Resources Bulletin (32) 953-964
Pesticides in stormwater runoff, within the Sacramento River Basin, California, were assessed during a storm that occurred in January 1994. Two organophosphate insecticides (diazinon and methidathion), two carbamate pesticides (molinate and carbofuran), and one triazine herbicide (simazine) were detected. Organophosphate pesticide concentrations increased with the rising stage of the hydrographs;...
Use of SAR data to study active volcanoes in Alaska
K.G. Dean, K. Engle, Z. Lu, J. Eichelberger, T. Neal, M. Doukas
1996, European Space Agency, (Special Publication) ESA SP 153-154
Synthetic Aperture Radar (SAR) data of Westdahl, Veniaminof, and Novarupta volcanoes in the Aleutian Arc of Alaska were analyzed to investigate recent surface volcanic processes. These studies support ongoing monitoring and research by the Alaska Volcano Observatory (AVO) in the North Pacific Ocean Region. Landforms and possible crustal deformation before,...
Response of common murres to the Exxon Valdez Oil Spill and long-term changes in the Gulf of Alaska marine ecosystem
John F. Piatt, Paul Anderson
S.D. Rice, R.B. Spies, D.A. Wolfe, B.A. Wright, editor(s)
1996, Conference Paper, Proceedings of the <i>Exxon Valdez</i> oil spill symposium: American Fisheries Society symposium 18
Short-term effects of the 1989 TV Exxon Valdez oil spill on seabirds were dramatic and well documented. Seabird populations at sea in the spill zone were immediately depressed, and more than 30,000 dead, oiled seabirds were recovered from beaches within months of the spill. It is estimated that 250,000 seabirds...
Gas in the Uinta Basin, Utah - Resources in continuous accumulations
J. W. Schmoker, T. D. Fouch, Ronald R. Charpentier
1996, Mountain Geologist (33) 95-104
Continuous-type gas plays can be envisioned as large areas within which the reservoir rock is everywhere charged with gas. As part of its 1995 National Assessment of oil and gas resources, the U.S. Geological Survey identified four continuous-type gas plays in the Uinta Basin. These occur in sandstone reservoirs of...
The upper mantle structure of the central Rio Grande rift region from teleseismic P and S wave travel time delays and attenuation
P.D. Slack, P.M. Davis, W.S. Baldridge, K.H. Olsen, A. Glahn, U. Achauer, W. Spence
1996, Journal of Geophysical Research B: Solid Earth (101) 16003-16023
The lithosphere beneath a continental rift should be significantly modified due to extension. To image the lithosphere beneath the Rio Grande rift (RGR), we analyzed teleseismic travel time delays of both P and S wave arrivals and solved for the attenuation of P and S waves for four seismic experiments spanning the Rio Grande rift. Two tomographic inversions...
Geohydrology and water quality of stratified-drift aquifers in the middle Connecticut River basin, west-central New Hampshire
S. M. Flanagan
1996, Water-Resources Investigations Report 94-4181
A study was done by the U.S. Geological Survey, in cooperation with the New Hampshire Department of Environmental Services, Water Resources Division, to describe the geohydrology and water quality of stratified-drift aquifers in the Middle Connecticut River Basin, west-central New Hampshire Stratified-drift aquifers discontinuously underlie 123 mi2 (square miles) of...
Water-vapor movement through unsaturated alluvium in Amargosa Desert near Beatty, Nevada - Current understanding and continuing studies: A section in Joint US Geological Survey, US Nuclear Regulatory Commission workshop on research related to low-level radioactive waste disposal, May 4-6, 1993, National Center, Reston, Virginia; Proceedings (WRI 95-4015)
David E. Prudic
Peter R. Stevens, Thomas J. Nicholson, editor(s)
1996, Report, Joint US Geological Survey, US Nuclear Regulatory Commission workshop on research related to low-level radioactive waste disposal, May 4-6, 1993, National Center, Reston, Virginia; Proceedings (WRI 95-4015)
Disposal of low-level radioactive wastes has been a concern since the 1950's. These wastes commonly are buried in shallow trenches (Fischer, 1986, p. 2). Water infiltrating into the trenches is considered the principal process by which contaminants are transported away from the buried wastes, although gaseous transport in some areas...
Estimating the effective spatial resolution of an AVHRR time series
D. J. Meyer
1996, International Journal of Remote Sensing (17) 2971-2980
A method is proposed to estimate the spatial degradation of geometrically rectified AVHRR data resulting from misregistration and off-nadir viewing, and to infer the cumulative effect of these degradations over time. Misregistrations are measured using high resolution imagery as a geometric reference, and pixel sizes are computed directly from satellite...
Mass and body-dimension relationships of polar bears in northern Alaska
George M. Durner, Steven C. Amstrup
1996, Wildlife Society Bulletin (24) 480-484
Models developed from morphometric parameters are useful for estimating body mass (M) of captured wild ursids. The accuracy of those models, however, may depend on sex, season, and geographic location of the population. We tested the suitability of reported models to predict mass of polar bears (Ursus maritimus) captured in...
Detectability, philopatry, and the distribution of dispersal distances in vertebrates
Walter D. Koenig, Dirk H. Van Vuren, Philip N. Hooge
1996, Trends in Ecology and Evolution (11) 514-517
Dispersal is of central importance to population biology, behavioral ecology and conservation. However, because field studies are based on finite study areas, nearly all dispersal distributions for vertebrates currently available are biased, often highly so. The inadequacy of dispersal data obtained directly by traditional methods using population studies of marked...
Grassland canopy parameters and their relationships to remotely sensed vegetation indices in the Nebraska Sand Hills
Bruce K. Wylie, Donovan D. DeJong, Larry L. Tieszen, Mario E. Biondini
1996, Geocarto International (11) 39-52
Relationships among spectral vegetation indices and grassland biophysical parameters including the effects of varying levels of standing dead vegetation, range sites, and range plant communities were examined. Range plant communities consisting of northern mixed grass prairie and a smooth brome field as well as range sites and management in a...
Numerical evaluation of static-chamber measurements of soil-atmospheric gas exchange--Identification of physical processes
Richard W. Healy, Robert G. Striegl, Thomas F. Russell, Gordon L. Hutchinson, Gerald P. Livingston
1996, Soil Science Society of America Journal (60) 740-747
The exchange of gases between soil and atmosphere is an important process that affects atmospheric chemistry and therefore climate. The static-chamber method is the most commonly used technique for estimating the rate of that exchange. We examined the method under hypothetical field conditions where diffusion was the only mechanism for...
