Development of Maximum Considered Earthquake Ground Motion Maps
E. V. Leyendecker, R. J. Hunt, A.D. Frankel, K.S. Rukstales
2000, Earthquake Spectra (16) 21-40
The 1997 NEHRP Recommended Provisions for Seismic Regulations for New Buildings use a design procedure that is based on spectral response acceleration rather than the traditional peak ground acceleration, peak ground velocity, or zone factors. The spectral response accelerations are obtained from maps prepared following the recommendations of the Building Seismic Safety...
A dynamic landscape model for fish in the Everglades and its application to restoration
H.D. Gaff, D.L. DeAngelis, L.J. Gross, R. Salinas, M. Shorrosh
2000, Ecological Modelling (127) 33-52
A model (ALFISH) for fish functional groups in freshwater marshes of the greater Everglades area of southern Florida has been developed. Its main objective is to assess the spatial pattern of fish densities through time across freshwater marshes. This model has the capability of providing a dynamic measure of the...
Swimming performance of larval robust redhorse Moxostoma robustum and low-velocity habitat modeling in the Oconee River, Georgia
Carl R. Ruetz III, Cecil A. Jennings
2000, Transactions of the American Fisheries Society (129) 398-407
The robust redhorse Moxostoma robustum occurs in an 85-km stretch of the Oconee River, Georgia, downstream of a hydropower dam. The population consists primarily of older individuals and recruitment in recent years has been minimal. Operation of the hydropower dam may have affected recruitment negatively by displacing newly hatched larvae...
Period doubling and other nonlinear phenomena in volcanic earthquakes and tremor
B.R. Julian
2000, Journal of Volcanology and Geothermal Research (101) 19-26
Evidence of subharmonic period-doubling cascades has recently been recognized in seismograms of volcanic tremor from several volcanoes. This phenomenon occurs only in nonlinear systems, and is the commonest route by which such systems change from periodic to chaotic behavior. It is predicted to occur in a model of volcanic tremor...
Type C botulism in dairy cattle from feed contaminated with a dead cat
F.D. Galey, R. Terra, R. Walker, J. Adaska, M.A. Etchebarne, B. Puschener, R.H. Whitlock, Tonie E. Rocke, D. Willoughby, E. Tor
2000, Journal of Veterinary Diagnostic Investigation (12) 204-209
Four hundred twenty-seven of 441 adult Holstein dairy cattle from a 1,200-cow dairy died over a 1-week period during early spring 1998. Affected animals were from 4 late lactation pens, one of which included the bull string. Signs included weakness, recumbency, watery diarrhea, and death. Eighty animals from the 4...
Chlorofluorocarbon dating of herbicide-containing well waters in Fresno and Tulare counties, California
F. Spurlock, K. Burow, N. Dubrovsky
2000, Journal of Environmental Quality (29) 474-483
Simazine, diuron, and bromacil are the most frequently detected currently registered pesticides in California groundwater. These herbicides have been used for several decades in Fresno and Tulare counties, California; however, previous data are inadequate to determine whether the detections are a result of recent or historical applications (i.e., within the...
Variability of bed mobility in natural, gravel‐bed channels and adjustments to sediment load at local and reach scales
Thomas E. Lisle, Jonathan M. Nelson, John Pitlick, Mary Ann Madej, Brent L. Barkett
2000, Water Resources Research (36) 3743-3755
Local variations in boundary shear stress acting on bed‐surface particles control patterns of bed load transport and channel evolution during varying stream discharges. At the reach scale a channel adjusts to imposed water and sediment supply through mutual interactions among channel form, local grain size, and local flow dynamics that...
Estimating the variance and integral scale of the transmissivity field using head residual increments
Li Zheng, Stephen E. Silliman
2000, Water Resources Research (36) 1353-1358
A modification of previously published solutions regarding the spatial variation of hydraulic heads is discussed whereby the semivariogram of increments of head residuals (termed head residual increments HRIs) are related to the variance and integral scale of the transmissivity field. A first‐order solution is developed for the case of a...
USGS National Seismic Hazard Maps
A.D. Frankel, C.S. Mueller, T. P. Barnhard, E. V. Leyendecker, R. L. Wesson, S. C. Harmsen, F. W. Klein, D. M. Perkins, N.C. Dickman, S.L. Hanson, M. G. Hopper
2000, Earthquake Spectra (16) 1-19
The U.S. Geological Survey (USGS) recently completed new probabilistic seismic hazard maps for the United States, including Alaska and Hawaii. These hazard maps form the basis of the probabilistic component of the design maps used in the 1997 edition of the NEHRP Recommended Provisions for Seismic Regulations for New Buildings and...
Modeling the effects of snowpack on heterotrophic respiration across northern temperate and high latitude regions: Comparison with measurements of atmospheric carbon dioxide in high latitudes
A. D. McGuire, J. M. Melillo, J. T. Randerson, W.J. Parton, Martin Heimann, R.A. Meier, Joy S. Clein, D. W. Kicklighter, W. Sauf
2000, Biogeochemistry (48) 91-114
Simulations by global terrestrial biogeochemical models (TBMs) consistently underestimate the concentration of atmospheric carbon dioxide (CO2) at high latitude monitoring stations during the nongrowing season. We hypothesized that heterotrophic respiration is underestimated during the nongrowing season primarily because TBMs do not generally consider the insulative effects of snowpack on soil...
Environmental history and tephrostratigraphy at Carp Lake, southwestern Columbia Basin, Washington, USA
C. Whitlock, A.M. Sarna-Wojcicki, P. J. Bartlein, R.J. Nickmann
2000, Conference Paper, Palaeogeography, Palaeoclimatology, Palaeoecology
Sediment cores from Carp Lake provide a pollen record of the last ca. 125,000 years that helps disclose vegetational and climatic conditions from the present day to the previous interglaciation (120-133 ka). The core also contained 15 tephra layers, which were characterised by electron-microprobe analysis of volcanic glass shards. Identified...
Mode of occurrence of arsenic in four US coals
A. Kolker, Frank E. Huggins, C.A. Palmer, N. Shah, S.S. Crowley, G.P. Huffman, R. B. Finkelman
2000, Fuel Processing Technology (63) 167-178
An integrated analytical approach has been used to determine the mode of occurrence of arsenic in samples of four widely used US coals: the Pittsburgh, Illinois #6, Elkhorn/Hazard, and Wyodak. Results from selective leaching, X-ray absorption fine structure (XAFS) spectroscopy, and electron microprobe analysis show that pyrite is the principal...
A log-normal distribution model for the molecular weight of aquatic fulvic acids
S.E. Cabaniss, Q. Zhou, P.A. Maurice, Y.-P. Chin, G. R. Aiken
2000, Environmental Science & Technology (34) 1103-1109
The molecular weight of humic substances influences their proton and metal binding, organic pollutant partitioning, adsorption onto minerals and activated carbon, and behavior during water treatment. We propose a lognormal model for the molecular weight distribution in aquatic fulvic acids to provide a conceptual framework for studying these size effects....
Gravitational stability of three-dimensional stratovolcano edifices
M.E. Reid, S.B. Christian, D.L. Brien
2000, Journal of Geophysical Research B: Solid Earth (105) 6043-6056
Catastrophic flank collapses have occurred at many stratovolcanoes worldwide. We present a three-dimensional (3-D) slope stability analysis for assessing and quantifying both the locations of minimum edifice stability and the expected volumes of potential failure. Our approach can search the materials underlying a topographic surface, represented as a digital elevation...
Sr and Nd isotopic compositions, age and petrogenesis of A-type granitoids of the Vernon Supersuite, New Jersey Highlands, USA
R.A. Volkert, M.D. Feigenson, L.C. Patino, J.S. Delaney, Avery A. Drake Jr.
2000, LITHOS (50) 325-347
Voluminous late Mesoproterozoic monzonite through granite of the Vernon Supersuite underlies an area of approximately 1300 km2 in the Highlands of northern New Jersey. The Vernon Supersuite consists of hastingsite ?? biotite-bearing granitoids of the Byram Intrusive Suite (BIS) and hedenbergite-bearing granitoids of the Lake Hopatcong Intrusive Suite (LHIS). These...
Monitoring air quality in mountains: Designing an effective network
D. L. Peterson
2000, Environmental Monitoring and Assessment (64) 81-91
A quantitatively robust yet parsimonious air-quality monitoring network in mountainous regions requires special attention to relevant spatial and temporal scales of measurement and inference. The design of monitoring networks should focus on the objectives required by public agencies, namely: 1) determine if some threshold has been exceeded (e.g., for regulatory...
Studies of volcanoes of Alaska by satellite radar interferometry
Z. Lu, C. Wicks Jr., D. Dzurisin, W. Thatcher, J. Power
Sawaya-Lacoste H., editor(s)
2000, Conference Paper
Interferometric synthetic aperture radar (InSAR) has provided a new imaging geodesy technique to measure the deformation of volcanoes at tens-of-meter horizontal resolution with centimeter to subcentimeter vertical precision. The two-dimensional surface deformation data enables the construction of detailed numerical models allowing the study of magmatic and tectonic processes beneath volcanoes....
The dependence of permeability on effective stress for an injection test in the Higashi-Hachimantai Geothermal Field
M. Nathenson
2000, Geophysical Research Letters (27) 589-592
A simple inverse-power relation for the influence of effective stress on permeability is used to explain the flow behavior during an injection test at the Higashi-Hachimantai geothermal field, Japan. The new analytical expression successfully models data from the experiment involving high-pressure injection and monitoring at an observation well....
Geochemical and mineralogical evidence from eolian sediments for northwesterly mid-Holocene paleowinds, central Kansas, USA
A.F. Arbogast, D.R. Muhs
2000, Quaternary International (67) 107-118
A prominent (4500 km2) dune field in the Great Plains is the Great Bend Sand Prairie of south-central Kansas. Dunes here overlie late Quaternary alluvium and were reactivated extensively in the late Holocene. Geomorphic and soil evidence suggests that the most likely eolian sand source is the Arkansas River valley...
Estimating formation properties from early-time oscillatory water levels in a pumped well
A.M. Shapiro, D.S. Oki
2000, Journal of Hydrology (236) 91-108
Hydrologists often attempt to estimate formation properties from aquifer tests for which only the hydraulic responses in a pumped well are available. Borehole storage, turbulent head losses, and borehole skin, however, can mask the hydraulic behavior of the formation inferred from the water level in the pumped well. Also, in...
Fire frequency in the Interior Columbia River Basin: Building regional models from fire history data
D. McKenzie, D. L. Peterson, James K. Agee
2000, Ecological Applications (10) 1497-1516
Fire frequency affects vegetation composition and successional pathways; thus it is essential to understand fire regimes in order to manage natural resources at broad spatial scales. Fire history data are lacking for many regions for which fire management decisions are being made, so models are needed to estimate past fire...
A revised load estimation procedure for the Susquehanna, Potomac, Patuxent, and Choptank rivers
Steven E. Yochum
2000, Water-Resources Investigations Report 2000-4156
The U.S. Geological Survey's Chesapeake Bay River Input Program has updated the nutrient and suspended-sediment load data base for the Susquehanna, Potomac, Patuxent, and Choptank Rivers using a multiple-window, center-estimate regression methodology. The revised method optimizes the seven-parameter regression approach that has been used historically by the program. The revised...
Numerical model of frazil ice and suspended sediment concentrations and formation of sediment laden ice in the Kara Sea
C. R. Sherwood
2000, Journal of Geophysical Research C: Oceans (105) 14061-14080
A one-dimensional (vertical) numerical model of currents, mixing, frazil ice concentration, and suspended sediment concentration has been developed and applied in the shallow southeastern Kara Sea. The objective of the calculations is to determine whether conditions suitable for turbid ice formation can occur during times of rapid cooling and wind-...
Demographic characteristics and population modeling: Chapter 8 in Status, ecology and conservation of the Southwestern Willow Flycatcher (RMRS-GTR-60)
Scott H. Stoleson, Mary J. Whitfield, Mark K. Sogge
Deborah M. Finch, Scott H. Stoleson, editor(s)
2000, General Technical Report RMRS-GTR-60-8
An understanding of the basic demography of a species is necessary to estimate and evaluate population trends. The relative impact of different demographic parameters on growth rates can be assessed through a sensitivity analysis, in which different parameters are altered singly to assess the effect on population growth. Identification of...
Laboratory measurements of compressional and shear wave speeds through methane hydrate
W.F. Waite, M.B. Helgerud, A. Nur, J.C. Pinkston, L.A. Stern, S. H. Kirby, W.B. Durham
2000, Conference Paper, Annals of the New York Academy of Sciences
Simultaneous measurements of compressional and shear wave speeds through polycrystalline methane hydrate have been made. Methane hydrate, grown directly in a wave speed measurement chamber, was uniaxially compacted to a final porosity below 2%. At 277 K, the compacted material had a compressional wave speed of 3650 ?? 50 m/s....
