Implications of uncertainty in exposure assessment for groundwater contamination
Eric G. Reichard, John A. Izbicki, Peter Martin
1995, Conference Paper, IAHS-AISH Publication
Decision-making on regulation, mitigation, and treatment of drinking water contamination depends, in part, on estimates of human exposure. Assessment of past, present and potential future exposure levels requires quantitative characterization of the contaminant sources, the transport of contaminants and the level of actual human exposure to the contaminated water. Failure...
A summary of the effects of mining and related activities on the sediment-trace element geochemistry of Lake Coeur d'Alene, Idaho, USA
A. J. Horowitz, K. A. Elrick, J. A. Robbins, R.B. Cook
1995, Journal of Geochemical Exploration (52) 135-144
During 1989 and 1990 a series of 12 gravity cores, and 150 surface grab samples were collected in Lake Coeur d'Alene, Idaho to determine trace element concentrations, partitioning and surface and subsurface distribution patterns in the bed sediments of the lake....
Zinc, copper, and lead geochemistry of oceanic igneous rocks - ridges, islands, and arcs
B. R. Doe
1995, International Geology Review (37) 379-420
Variations in the abundances of Zn, Cu, and Pb are found to be useful in identifying tectonic regimes and separating oceanisland basalts into enriched- and depleted-source categories. The average Zn, Cu, and Pb contents of normal mid-ocean ridge basalts (N-MORB) are 84, 70, and 0.35 ppm, respectively. Differences in...
Regional mapping of karst terrains in order to avoid potential environmental problems
K.S. Johnson, J.F. Quinlan
1995, Cave and Karst Science - Transactions British Cave Research Association (21) 37-39
The oklahoma Geological Survey will prepare a map of the State at a scale of 1:500,000 to show karst terrains and associated environmental problems in Oklahoma. Surface and near-surface carbonates (limestone and dolomite) comprise about 6% of the surface area of the State, whereas sulphates (gypsum and anhydrite) comprise about...
Estimation of regionalized compositions: A comparison of three methods
V. Pawlowsky, Ricardo A. Olea, J.C. Davis
1995, Mathematical Geology (27) 105-127
A regionalized composition is a random vector function whose components are positive and sum to a constant at every point of the sampling region. Consequently, the components of a regionalized composition are necessarily spatially correlated. This spatial dependence-induced by the constant sum constraint-is a spurious spatial correlation and may lead...
Algorithm for resistance to flow and transport in sand-bed channels
J. P. Bennett
1995, Journal of Hydraulic Engineering (121) 578-590
An algorithm is developed that relates depth to discharge and determines bed- and suspended-load transport for the entire range of bed forms found in sand-bed channels; equilibrium-state geometry of lower flow regime bedforms is also predicted. A Meyer-Peter-type formulation is used to compute sand transport in the bed-load layer and...
The effect of surface anisotropy and viewing geometry on the estimation of NDVI from AVHRR
David Meyer, M. Verstraete, B. Pinty
1995, Remote Sensing Reviews (12) 3-27
Since terrestrial surfaces are anisotropic, all spectral reflectance measurements obtained with a small instantaneous field of view instrument are specific to these angular conditions, and the value of the corresponding NDVI, computed from these bidirectional reflectances, is relative to the particular geometry of illumination and viewing at the time of...
Simulation of interaction between ground water in an alluvial aquifer and surface water in a large braided river
S. A. Leake, M. R. Lilly
1995, Conference Paper, International Symposium on Groundwater Management - Proceedings
The Fairbanks, Alaska, area has many contaminated sites in a shallow alluvial aquifer. A ground-water flow model is being developed using the MODFLOW finite-difference ground-water flow model program with the River Package. The modeled area is discretized in the horizontal dimensions into 118 rows and 158 columns of approximately 150-meter...
Soy protein in diets of rainbow trout: effects on growth, protein absorption, gastrointestinal histology and nonspecific serologic and immune response
G. L. Rumsey, J.G. Endres, P.R. Bowser, K. A. Earnest-Koons, D. P. Anderson, A.K. Siwicki
1995, Book chapter, Nutrition and Utilization Technology Aquaculture
No abstract available at this time...
Water-use efficiency as monitored by dendrochemistry
R.P. Guyette, B.E. Cutter
T.E. Lewis, editor(s)
1995, Book chapter, Tree rings as indicators of ecosystem health
Determination of elemental content off rocks by laser ablation inductively coupled plasma mass spectrometry
F.E. Lichte
1995, Analytical Chemistry (67) 2479-2485
A new method of analysis for rocks and soils is presented using laser ablation inductively coupled plasma mass spectrometry. It is based on a lithium borate fusion and the free-running mode of a Nd/YAG laser. An Ar/N2 sample gas improves sensitivity 7 ?? for most elements. Sixty-three elements are characterized...
Implications of Coulomb plasticity for the velocity dependence of experimental faults
N.M. Beeler, T.E. Tullis
1995, Pure and Applied Geophysics PAGEOPH (144) 251-276
Simulated fault gouges often deform more stably than initially bare surfaces of the same composition. It is important to understand why the sliding stability is enhanced because the presence of gouge on natural faults may have the same effect as seen in experiments, and thus explain the absence of earthquakes...
The structural and geochemical evolution of the continental crust: Support for the oceanic plateau model of continental growth
D. Abbott, Walter D. Mooney
1995, Reviews of Geophysics (33) 231-242
The problem of the origin of the continental crust can be resolved into two fundamental questions: (1) the location and mechanisms of initial mantle extraction of the primitive crust and (2) the processes by which this primitive crust is converted into the continental crust that presently exists....
Duck nest success in the prairie potholes
Terry L. Shaffer, Wesley E. Newton
Edward T. LaRoe, Gaye S. Farris, Catherine E. Puckett, Peter D. Doran, Michael J. Mac, editor(s)
1995, Book chapter, Our living resources: A report to the nation on the distribution, abundance, and health of U.S. plants, animals, and ecosystems
Since the early 1970's, the numbers of some waterfowl species such as mallard (Anas platyrhynchos), blue-winged teal (A. discors), and northern pintail (A. acuta) have reached or nearly reached the lowest ever recorded. Low nest success (the proportion of nests in which one or more eggs hatch) in key breeding...
The chemical and hydrologic structure of Poas volcano, Costa Rica
G.L. Rowe Jr., S.L. Brantley, J.F. Fernandez, A. Borgia
1995, Journal of Volcanology and Geothermal Research (64) 233-267
Comparison of the chemical characteristics of spring and river water draining the flanks of Poas Volcano, Costa Rica indicates that acid chloride sulfate springs of the northwestern flank of the volcano are derived by leakage and mixing of acid brines formed in the summit hydrothermal system with dilute flank groundwater....
Seismic images of the Brooks Range, Arctic Alaska, reveal crustal- scale duplexing
G. S. Fuis, A. R. Levander, W. J. Lutter, E. S. Wissinger, Thomas E. Moore, N.I. Christensen
1995, Geology (23) 65-68
An integrated set of seismic reflection and refraction data collected across the Brooks Range, Arctic Alaska, in 1990, has yielded a composite image of this Mesozoic and Cenozoic fold-and-thrust belt that reveals duplexing to lower-crustal depths. Interpretations from this image are as follows....
Channel degradation in southeastern Nebraska Rivers
Kenneth L. Wahl, Linda S. Weiss
Ward Rim J., editor(s)
1995, Conference Paper, Watershed Management Symposium - Proceedings
Many stream channels in southeastern Nebraska were dredged and straightened during 1904-15. The resulting channels were both shorter and steeper than the original channels. Tests for time trends were conducted using the nonparametric Kendall tau test to see if the channels have responded to these changes. Tests were conducted on...
A mechanism for decoupling within the oceanic lithosphere revealed in the Troodos ophiolite
Susan M. Agar, Kim D. Klitgord
1995, Nature (374) 232-238
Contrasting kinematic histories recorded in the sheeted dykes and underlying plutonic rocks of the Troodos ophiolite provide a new perspective on the mechanical evolution of oceanic spreading centres. The kinematic framework of the decoupling zone that partitions deformation between the sheeted dykes and plutonics contrasts with low-angle detachment models for...
Strong-acid, carboxyl-group structures in fulvic acid from the Suwannee River, Georgia. 2. Major structures
J.A. Leenheer, R.L. Wershaw, M.M. Reddy
1995, Environmental Science & Technology (29) 399-405
Polycarboxylic acid structures that account for the strong-acid characteristics (pKa1 near 2.0) were examined for fulvic acid from the Suwannee River. Studies of model compounds demonstrated that pKa values near 2.0 occur only if the a-ether or a-ester groups were in cyclic structures with two to three additional electronegative functional...
Tectonic setting of the Portland-Vancouver area, Oregon and Washington: Constraints from low-altitude aeromagnetic data
R.J. Blakely, R.E. Wells, T.S. Yelin, I. P. Madin, M.H. Beeson
1995, Geological Society of America Bulletin (107) 1051-1062
Seismic activity in the Portland-Vancouver metropolitan area may be associated with various mapped faults that locally offset volcanic basement of Eocene age and younger. This volcanic basement is concealed in most places by young deposits, vegetation, and urban development. The U.S. Geological Survey...
Movements, distribution, and population dynamics of polar bears in the Beaufort Sea
Steven C. Amstrup
1995, Thesis
Measurements in the bottom boundary layer on the Amazon subaqueous delta
D.A. Cacchione, D.E. Drake, R.W. Kayen, R.W. Sternberg, G.C. Kineke, G. B. Tate
1995, Marine Geology (125) 235-257
An instrumented bottom tripod (GEOPROBE) recorded flow and suspended sediment data in the bottom boundary layer above the lower foresets of the Amazon subaqueous delta in 65 m mean water depth in February, 1990. After about two weeks of operation the apparent seafloor at the tripod site rapidly elevated over...
Migratory bird population changes in North Dakota
Lawrence D. Igl, Douglas H. Johnson
Edward T. LaRoe, Gaye S. Farris, Catherine E. Puckett, Peter D. Doran, Michael J. Mac, editor(s)
1995, Book chapter, Our living resources: A report to the nation on the distribution, abundance, and health of U.S. plants, animals, and ecosystems
The status of migratory bird populations in North America has received increased attention in recent years. Much of this consideration has been on Neotropical migrants, especially those associated with eastern forests. The status of migratory bird populations in the Great Plains has received far less attention. During the past quarter-century,...
Rainfall thresholds for the initiation of debris flows at La Honda, California
R. C. Wilson, G. F. Wieczorek
1995, Environmental & Engineering Geoscience (1) 11-27
In order to study the relation between heavy rainfall, shallow pore pressures, and slope stability in hillslopes susceptible to debris flows, we have been observing debris flows and measuring rainfall and hillslope pore pressures in a 10-km2 study area in the central Santa Cruz Mountains near La Honda, California. A simple...
Gemstones: An overview of production of specific U.S. gemstones
Gordon T. Austin
1995, Report
