Crustal displacements due to continental water loading
T. Van Dam, J. Wahr, P. C. D. Milly, A.B. Shmakin, G. Blewitt, D. Lavallee, K.M. Larson
2001, Geophysical Research Letters (28) 651-654
The effects of long-wavelength (> 100 km), seasonal variability in continental water storage on vertical crustal motions are assessed. The modeled vertical displacements (??rM) have root-mean-square (RMS) values for 1994-1998 as large as 8 mm, with ranges up to 30 mm, and are predominantly annual in character. Regional strains are...
Improving the quality of mass produced maps
Jeffrey D. Simley
2001, Cartography and Geographic Information Science (28) 97-110
Quality is critical in cartography because key decisions are often made based on the information the map communicates. The mass production of digital cartographic information to support geographic information science has now added a new dimension to the problem of cartographic quality, as problems once limited to small volumes can...
Myrmecophagy by Yellowstone grizzly bears
David J. Mattson
2001, Canadian Journal of Zoology (79) 779-793
I used data collected during a study of radio-marked grizzly bears (Ursus arctos horribilis) in the Yellowstone region from 1977 to 1992 to investigate myrmecophagy by this population. Although generally not an important source of energy for the bears (averaging <5% of fecal volume at peak consumption), ants may have...
Pleistocene reduction of polar ice caps: Evidence from Cariaco Basin marine sediments
R.Z. Poore, H.J. Dowsett
2001, Geology (29) 71-74
Sea level is projected to rise between 13 and 94 cm over the next 100 yr due to continued climate warming. The sea-level projections assume that polar ice sheets will remain stable or even increase on time scales of centuries, but controversial geologic evidence suggests that current polar ice sheets...
U.S. Geological Survey programs and investigations related to soil and water conservation
W. R. Osterkamp, J. R. Gray
2001, International Journal of Sediment Research (16) 421-429
The U.S. Geological Survey has a rich tradition of collecting hydrologic data, especially for fluxes of water and suspended sediment, that provide a foundation for studies of soil and water conservation. Applied and basic research has included investigations of the effects of land use on rangelands, croplands, and forests; hazards...
Soil efflux and total emission rates of magmatic CO2 at the horseshoe lake tree kill, mammoth mountain, California, 1995-1999
T.M. Gerlach, M.P. Doukas, K.A. McGee, R. Kessler
2001, Chemical Geology (177) 101-116
We report the results of eight soil CO2 efflux surveys by the closed circulation chamber method at the Horseshoe Lake tree kill (HLTK) - the largest tree kill on Mammoth Mountain. The surveys were undertaken from 1995 to 1999 to constrain total HLTK CO2 emissions and to evaluate occasional efflux...
Elevated carbon dioxide flux at the Dixie Valley geothermal field, Nevada; relations between surface phenomena and the geothermal reservoir
D. Bergfeld, F. Goff, C. J. Janik
2001, Chemical Geology (177) 43-66
In the later part of the 1990s, a large die-off of desert shrubs occurred over an approximately 1 km2 area in the northwestern section of the Dixie Valley (DV) geothermal field. This paper reports results from accumulation-chamber measurements of soil CO2 flux from locations in the dead zone and stable...
Density model of the Cascadia subduction zone
T.V. Romanyuk, Walter D. Mooney, R.J. Blakely
2001, Izvestiya, Physics of the Solid Earth (37) 617-635
The main goal of this work is to construct self-consistent density models along two profiles crossing the northern and central Cascadia subduction zone that have been comprehensively studied on the basis of geological, geophysical, etc. data....
Geochemical and mineralogical studies of dinosaur bone from the Morrison Formation at Dinosaur Ridge
P.J. Modreski
2001, Mountain Geologist (38) 111-118
The dinosaur bones first discovered in 1877 in the Upper Jurassic Morrison Formation at Morrison, Colorado were the first major find of dinosaur skeletons in the western U.S. and led to the recognition of four new dinosaur genera (Apatosaurus, Allosaurus, Diplodocus, and Stegosaurus). Eight articles dealing with these bones which...
Wavefield properties of a shallow long-period event and tremor at Kilauea Volcano, Hawaii
G. Saccorotti, B. Chouet, P. Dawson
2001, Journal of Volcanology and Geothermal Research (109) 163-189
The wavefields of tremor and a long-period (LP) event associated with the ongoing eruptive activity at Kilauea Volcano, Hawaii, are investigated using a combination of dense small-aperture (300 m) and sparse large-aperture (5 km) arrays deployed in the vicinity of the summit caldera. Measurements of azimuth and slowness for tremor...
Drawdown and stream depletion produced by pumping in the vicinity of a partially penetrating stream
J.J. Butler Jr., V.A. Zlotnik, Ming-shu Tsou
2001, Ground Water (39) 651-659
Commonly used analytical approaches for estimation of pumping-induced drawdown and stream depletion are based on a series of idealistic assumptions about the stream-aquifer system. A new solution has been developed for estimation of drawdown and stream depletion under conditions that are more representative of those in natural systems (finite width...
Application of a nonlinear slug test model
C.D. McElwee
2001, Ground Water (39) 737-744
Knowledge of the hydraulic conductivity distribution is of utmost importance in understanding the dynamics of an aquifer and in planning the consequences of any action taken upon that aquifer. Slug tests have been used extensively to measure hydraulic conductivity in the last 50 years since Hvorslev's (1951) work. A general...
Interparticle collision of natural sediment grains in water
Mark W. Schmeeckle, Jonathan M. Nelson, John Pitlick, James P. Bennett
2001, Water Resources Research (37) 2377-2391
Elastohydrodynamic theory and measurements of particle impacts on an inclined glass plane in water are used to investigate the mechanics of interparticle collisions in sediment‐transporting flows. A collision Stokes number is proposed as a measure of the momentum of an interparticle collision versus the viscous pressure force in the interstitial...
Initial yield to depth relation for water wells drilled into crystalline bedrock - Pinardville quadrangle, New Hampshire
L.J. Drew, J.H. Schuenemeyer, T.R. Amstrong, D. M. Sutphin
2001, Ground Water (39) 676-684
A model is proposed to explain the statistical relations between the mean initial water well yields from eight time increments from 1984 to 1998 for wells drilled into the crystalline bedrock aquifer system in the Pinardville area of southern New Hampshire and the type of bedrock, mean well depth, and...
MAUP: Modifiable Areal Unit Problem in raster GIS datasets. Raster pixels as modifiable areas
Usery E. Lyn
2001, GIM International (15) 43-45
The Modifiable Areal Unit Problem (MAUP) is a well-studied aspect of geographic phenomena. It is usually associated with socio-economic data collected by census enumeration units. This problem also applies directly to geographic data in raster formats, including both GIS categorical data layers and remotely sensed images. The author briefly provides...
Subglacial sediments: A regional geological template for iceflow in West Antarctica
M. Studinger, R.E. Bell, D. D. Blankenship, C. A. Finn, R.A. Arko, D. L. Morse, I. Joughin
2001, Geophysical Research Letters (28) 3493-3496
We use aerogeophysical data to estimate the distribution of marine subglacial sediments and fault-bounded sedimentary basins beneath the West Antarctic Ice Sheet (WAIS). We find that significant ice flow occurs exclusively in regions covered by subglacial sediments. The onsets and lateral margins of ice streams coincide with the limit of...
A method for mapping apparent stress and energy radiation applied to the 1994 Northridge earthquake fault zone-revisited
Art McGarr, Joe B. Fletcher
2001, Geophysical Research Letters (28) 3529-3532
McGarr and Fletcher (2000) introduced a technique for estimating apparent stress and seismic energy radiation associated with small patches of a larger fault plane and then applied this method to the slip model of the Northridge earthquake (Wald et al., 1996). These results must be revised because we did not...
Characterization of the Mississippian chat in south-central Kansas
W. Lynn Watney, W. J. Guy, Alan Byrne
2001, American Association of Petroleum Geologists Bulletin (85) 85-113
To understand production from low resistivity-high porosity Mississippian chat reservoirs in south-central Kansas it is necessary to understand the nature of deposition and diagenesis, how tectonics is a factor, the lithofacies controls on petrophysical properties, and log response to these properties. The initial mudstones to sponge-spicule wacke-packstones were deposited...
Protection of rainbow trout against infectious hematopoietic necrosis virus four days after specific or semi-specific DNA vaccination
S. E. LaPatra, S. Corbeil, G. R. Jones, W. D. Shewmaker, N. Lorenzen, Eric Anderson, Gael Kurath
2001, Vaccine (19) 4011-4019
A DNA vaccine against a fish rhabdovirus, infectious hematopoietic necrosis virus (IHNV), was shown to provide significant protection as soon as 4 d after intramuscular vaccination in 2 g rainbow trout (Oncorhynchus mykiss) held at 15°C. Nearly complete protection was also observed at...
The variability of root cohesion as an influence on shallow landslide susceptibility in the Oregon Coast Range
K. M. Schmidt, J. J. Roering, J. D. Stock, W. E. Dietrich, D. R. Montgomery, T. Schaub
2001, Canadian Geotechnical Journal (38) 995-1024
Decades of quantitative measurement indicate that roots can mechanically reinforce shallow soils in forested landscapes. Forests, however, have variations in vegetation species and age which can dominate the local stability of landslide-initiation sites. To assess the influence of this variability on root cohesion we examined scarps of landslides triggered during...
Changes in sample collection and analytical techniques and effects on retrospective comparability of low-level concentrations of trace elements in ground water
T. Ivahnenko, Z. Szabo, J. Gibs
2001, Water Research (35) 3611-3624
Ground-water sampling techniques were modified to reduce random low-level contamination during collection of filtered water samples for determination of trace-element concentrations. The modified sampling techniques were first used in New Jersey by the US Geological Survey in 1994 along with inductively coupled plasma-mass spectrometry (ICP-MS) analysis to determine the concentrations...
Salt diapirs in the Dead Sea basin and their relationship to Quaternary extensional tectonics
A. Al-Zoubi, Uri S. ten Brink
2001, Marine and Petroleum Geology (18) 779-797
Regional extension of a brittle overburden and underlying salt causes differential loading that is thought to initiate the rise of reactive diapirs below and through regions of thin overburden. We present a modern example of a large salt diapir in the Dead Sea pull-apart basin, the Lisan diapir, which we...
The national stream quality accounting network: A flux-basedapproach to monitoring the water quality of large rivers
R. P. Hooper, Brent T. Aulenbach, V.J. Kelly
2001, Hydrological Processes (15) 1089-1106
Estimating the annual mass flux at a network of fixed stations is one approach to characterizing water quality of large rivers. The interpretive context provided by annual flux includes identifying source and sink areas for constituents and estimating the loadings to receiving waters, such as reservoirs or the ocean. Since...
Associations of grassland birds with landscape factors in southern Wisconsin
Christine Ribic, D. W. Sample
2001, American Midland Naturalist (146) 105-121
We investigated the association of grassland birds with field- and landscape-level habitat variables in south-central Wisconsin during 1985–1987. Landscape-level variables were measured and digitized at 200, 400 and 800 m from the perimeter of 38 200 m × 100 m strip transects. A mixture of field and landscape variables was...
Impact of the Conservation Reserve Program on duck recruitment in the U.S. Prairie Pothole Region
Ronald E. Reynolds, Terry L. Shaffer, Randy W. Renner, Wesley E. Newton, Bruce D.J. Batt
2001, Journal of Wildlife Management (65) 765-780
The U.S. Department of Agriculture (USDA)'s Conservation Reserve Program (CRP) resulted in the conversion of about 1.9 million ha of cropland to perennial grass cover in the Prairie Pothole Region of North Dakota, South Dakota, and northeastern Montana by 1992. Many wildlife managers believed this cover would provide benefits to...
