Precipitation, streamflow, and water-quality data from selected sites in the City of Charlotte and Mecklenburg County, North Carolina, 1995-97
J. B. Robinson, W. F. Hazell, R. G. Garrett
1998, Open-File Report 98-67
Precipitation data were collected at 46 precipitation sites and 3 atmospheric deposition sites, and hydrologic data were collected at 9 stream sites in the vicinity of Charlotte and Mecklenburg County, North Carolina, from July 1995 through June 1997. Data were collected to identify the type, concentration, and amount of nonpoint-source...
A simplified economic filter for open-pit gold-silver mining in the United States
Donald A. Singer, W. David Menzie, Keith R. Long
1998, Open-File Report 98-207
In resource assessments of undiscovered mineral deposits and in the early stages of exploration, including planning, a need for prefeasibility cost models exists. In exploration, these models to filter economic from uneconomic deposits help to focus on targets that can really benefit the exploration enterprise. In resource assessment, these models...
Aquifer systems in the Great Basin region of Nevada, Utah, and adjacent states; summary report
J. R. Harrill, David E. Prudic
1998, Professional Paper 1409-A
Findings of the Great Basin Regional Aquifer System Analysis (RASA) are summarized. The Great Basin RASA study encompasses an area of about 140,000 square miles. Regional hydrology and ground-water hydrology of the area are described. Five models of basin-fill aquifers, a ground-water flow model of the Fish Springs system, and...
Geologic map of the Dao, Harmakhis, and Reull Valles region of Mars
Katherine H. Price
1998, IMAP 2557
The geology for this map was compiled using Viking Orbiter images on 1:500,000- scale photomosaics of the Mars Transverse Mercator quadrangles -40262, -40267, and -40272. This map represents a detailed extension of regional geologic mapping of the east Hellas rim (Crown...
An 85-year study of saguaro (Carnegiea gigantea) demography
Elizabeth A. Pierson, Raymond M. Turner
1998, Ecology (79) 2676-2693
The saguaro population in a 700-ha area at the Desert Laboratory on Tumamoc Hill, Tucson, Arizona, was censused in 1908, one year after livestock were excluded. In 1964, four 10-ha plots were established within the original area to determine the effect of slope aspect on plant growth and demography. The...
Establishment of woody riparian vegetation in relation to annual patterns of streamflow, Bill Williams River, Arizona
P.B. Shafroth, G.T. Auble, J.C. Stromberg, D.T. Patten
1998, Wetlands (18) 577-590
Previous studies have revealed the close coupling of components of annual streamflow hydrographs and the germination and establishment of Populus species. Key hydrograph components include the timing and magnitude of flood peaks, the rate of decline of the recession limb, and the magnitude of base flows. In this...
Seasonal differences in plasma cortisol and gill corticosteroid receptors in upper and lower mode juvenile Atlantic salmon
J. Mark Shrimpton, Stephen D. McCormick
1998, Aquaculture (168) 205-219
Circulating plasma cortisol and gill corticosteroid receptors (CR) have been observed to change seasonally in conjunction with smolting in Atlantic salmon. To differentiate whether these changes are seasonal or ontogenic, juvenile Atlantic salmon parr were separated by size into upper (UM) and lower mode (LM) in September. At monthly intervals,...
An overview of San Francisco Bay PORTS
Ralph T. Cheng, David McKinnie, Chad English, Richard E. Smith
1998, Conference Paper
The Physical Oceanographic Real-Time System (PORTS) provides observations of tides, tidal currents, and meteorological conditions in real-time. The San Francisco Bay PORTS (SFPORTS) is a decision support system to facilitate safe and efficient maritime commerce. In addition to real-time observations, SFPORTS includes a nowcast numerical model forming a San Francisco...
Estimating the effectiveness of further sampling inspecies inventories
Kim A. Keating, James F. Quinn, M.A. Ivie, L.L. Ivie
1998, Ecological Applications (8) 1239-1249
Estimators of the number of additional species expected in the next Δn samples offer a potentially important tool for improving cost-effectiveness of species inventories but are largely untested. We used Monte Carlo methods to compare 11 such estimators, across a range of community structures and sampling regimes, and validated our results,...
Non-double-couple earthquakes 2. Observations
A.D. Miller, G.R. Foulger, B.R. Julian
1998, Reviews of Geophysics (36) 551-568
Most studies assume that earthquakes have double-couple (DC) source mechanisms, corresponding to shear motion on planar faults. However, many well-recorded earthquakes have radiation patterns that depart radically from this model, indicating fundamentally different source processes. Seismic waves excited by advective processes, such as landslides and volcanic eruptions, are consistent with...
Population models of burrowing mayfly recolonization in western Lake Erie
Charles P. Madenjian, Don W. Schloesser, Kenneth A. Krieger
1998, Ecological Applications (8) 1206-1212
Burrowing mayflies, Hexagenia spp. (H. limbata and H. rigida), began recolonizing western Lake Erie during the 1990s. Survey data for mayfly nymph densities indicated that the population experienced exponential growth between 1991 and 1997. To predict the time to full recovery of the mayfly population, we fitted logistic models, ranging in carrying capacity from...
Non-double-couple earthquakes. 1. Theory
B.R. Julian, A.D. Miller, G.R. Foulger
1998, Reviews of Geophysics (36) 525-549
Historically, most quantitative seismological analyses have been based on the assumption that earthquakes are caused by shear faulting, for which the equivalent force system in an isotropic medium is a pair of force couples with no net torque (a “double couple,” or DC). Observations of increasing quality and coverage, however,...
Modern and historical bathymetry of Florida Bay
Mark Hansen, Nancy DeWitt
1998, Fact Sheet 096-98
No abstract available....
Analysis of ground-water flow and saltwater encroachment in the shallow aquifer system of Cape May County, New Jersey
Frederick J. Spitz
1998, Water Supply Paper 2490
Cape May County, New Jersey, is on a natural peninsula that is virtually surrounded by saltwater. A calibrated quasi-three-dimensional sharp-interface model was used to simulate ground-water flow in the shallow aquifer system under two water-supply-development alternatives for a 30-year planning period. The alternatives involve modest increases in withdrawals in combination...
Critical evaluation and selection of standard state thermodynamic properties for chromium metal and its aqueous ions, hydrolysis species, oxides, and hydroxides
James W. Ball, D. Kirk Nordstrom
1998, Journal of Chemical & Engineering Data (43) 895-918
This review critically evaluates the reported thermodynamic data on chromium metal, oxides, hydroxides, free aqueous ions, and hydrolysis species. Several discrepancies and inconsistencies have been uncovered and resolved to improve equilibrium calculations for chemical modeling and related engineering purposes. A revised set of data is derived from evaluation of electrochemical...
Geologic controls on the formation of lakes in north-central Florida
Jack L. Kindinger, Jeffrey B. Davis, James G. Flocks
Janet K. Pitman, Alan R. Carroll, editor(s)
1998, Report, Modern and Ancient Lake Systems: New Problems and Perspectives, 1998
Fluid exchange between surficial waters and groundwater, as well as the processes that control this exchange, are of critical concern to water management districts and planners. Digital high-resolution seismic systems were used to collect geophysical data from 30 lakes of north-central Florida. Although using seismic profile data in the past...
Suppression of large earthquakes by stress shadows: A comparison of Coulomb and rate-and-state failure
Ruth A. Harris, Robert W. Simpson
1998, Journal of Geophysical Research Solid Earth (103) 24439-24451
Stress shadows generated by California's two most recent great earthquakes (1857 Fort Tejon and 1906 San Francisco) substantially modified 19th and 20th century earthquake history in the Los Angeles basin and in the San Francisco Bay area. Simple Coulomb failure calculations, which assume that earthquakes can be modeled as static...
Estimation of temporal variability of survival in animal populations
William R. Gould, James D. Nichols
1998, Ecology (79) 2531-2538
Temporal variation of demographic characteristics for animal populations is of interest to both ecologists and biological modelers. The standard deviation of a series of estimated parameter values (e.g., estimated population size) or some function thereof (e.g., log of the estimated parameters) is commonly used as a measure of temporal variability....
Carbon storage and late Holocene chronostratigraphy of a Mississippi River deltaic marsh, St. Bernard Parish, Louisiana
H. W. Markewich, editor(s)
1998, Open-File Report 98-36
Today, the causes, results, and time scale(s) of climate change, past and potential, are the focus of much research, news coverage, and pundit speculation. Many of the US government scientific agencies have some funds earmarked for research into past and (or) future climate change (National Science and Technology Council, 1997)....
Addition of MOC3D solute-transport model capability to the U.S. Geological Survey MODFLOW-96 graphical-user interface using Argus open numerical environments
G.Z. Hornberger, Leonard F. Konikow
1998, Open-File Report 98-188
No abstract available....
Compilation of 29 sonic and density logs from 23 oil test wells in western Washington State
Thomas M. Brocher, April L. Ruebel
1998, Open-File Report 98-249
Three-dimensional velocity models for Puget Sound provide a means for better understanding the lateral variations in strong ground motions recorded during local earthquakes in Puget Lowland. We have compiled 29 sonic and density logs from 23 oil test wells to help us determine the geometry and physical properties of the...
Antarctic ice sheet; computer animations and paper model
Tau Rho Alpha, Alan K. Cooper
1998, Open-File Report 98-353-A
This report illustrates, through computer animation and a paper model, why there are changes on the ice sheet that covers the Antarctica continent. By studying the animations and the paper model, students will better understand the evolution of the Antarctic ice sheet. Included in the paper and diskette versions of this...
Modeling discharge, temperature, and water quality in the Tualatin River, Oregon
S.A. Rounds, T. M. Wood, D. D. Lynch
1998, Open-File Report 98-186
Statistical analysis and mathematical modeling of a tracer test on the Santa Clara River, Ventura County, California
Katherine S. Paybins, Tracy Nishikawa, John A. Izbicki, Eric G. Reichard
1998, Water-Resources Investigations Report 97-4275
To better understand flow processes, solute-transport processes, and ground-water/surface-water interactions on the Santa Clara River in Ventura County, California, a 24-hour fluorescent-dye tracer study was performed under steady-state flow conditions on a 28-mile reach of the river. The study reach includes perennial (uppermost and lowermost) subreaches and ephemeral subreaches of the...
Slide show on gravel deposit models and measuring aggregate quality, Front Range urban corridor, Colorado
David A. Lindsey, William H. Langer
1998, Open-File Report 98-332
