Applicability of NASQAN data for ecosystem assessments on the Missouri River
Dale W. Blevins, James Fairchild
2001, Hydrological Processes (15) 1347-1362
The effectiveness of ecological restoration efforts on large developed rivers is often unknown because comprehensive ecological monitoring programs are often absent. Although Eulerian water-quality monitoring programs, such as the National Stream Quality Accounting Network (NASQAN) program, are more common, they are usually not designed for ecological assessment. Therefore, this paper...
Macroinvertebrate instream flow studies after 20 years: A role in stream management and restoration
James A. Gore, James B. Layzer, Jim Mead
2001, Regulated Rivers: Research & Management (17) 527-542
Over the past two decades of refinement and application of instream flow evaluations, we have examined the hydraulic habitat of aquatic macroinvertebrates in a variety of conditions, along with the role of these macroinvertebrates in sustaining ecosystem integrity. Instream flow analyses assume that predictable changes in channel flow characteristics can,...
The trade-off between food and temperature in the habitat choice of bluegill sunfish
M. L. Wildhaber
2001, Journal of Fish Biology (58) 1476-1478
A model is presented to describe the trade-off between food and temperature in bluegills Lepomis macrochirus, where temperature was the primary factor used in determining the patch in which to reside....
Empirical Green's function analysis of recent moderate events in California
S. E. Hough
2001, Bulletin of the Seismological Society of America (91) 456-467
I use seismic data from portable digital stations and the broadband Terrascope network in southern California to investigate radiated earthquake source spectra and discuss the results in light of previous studies on both static stress drop and apparent stress. Applying the empirical Green's function (EGF) method to two sets of...
Resolution analysis of finite fault source inversion using one- and three-dimensional Green's functions 1. Strong motions
R.W. Graves, D.J. Wald
2001, Journal of Geophysical Research B: Solid Earth (106) 8745-8766
We develop a methodology to perform finite fault source inversions from strong motion data using Green's functions (GFs) calculated for a three-dimensional (3-D) velocity structure. The 3-D GFs are calculated numerically by inserting body forces at each of the strong motion sites and then recording the resulting strains along the...
The failure of earthquake failure models
J. Gomberg
2001, Journal of Geophysical Research B: Solid Earth (106) 16253-16263
In this study I show that simple heuristic models and numerical calculations suggest that an entire class of commonly invoked models of earthquake failure processes cannot explain triggering of seismicity by transient or "dynamic" stress changes, such as stress changes associated with passing seismic waves. The models of this class...
Historical effects of El Nino and La Nina events on the seasonal evolution of the montane snowpack in the Columbia and Colorado River Basins
Martyn P. Clark, Mark C. Serreze, Gregory J. McCabe
2001, Water Resources Research (37) 741-757
Snow‐water equivalent (SWE) data measured at several hundred montane sites in the western United States are used to examine the historic effects of El Nino and La Nina events on seasonal snowpack evolution in the major subbasins in the Columbia and Colorado River systems. Results are used to predict annual...
A minimalist probabilistic description of root zone soil water
P. C. D. Milly
2001, Water Resources Research (37) 457-463
The probabilistic response of depth‐integrated soil water to given climatic forcing can be described readily using an existing supply‐demand‐storage model. An apparently complex interaction of numerous soil, climate, and plant controls can be reduced to a relatively simple expression for the equilibrium probability density function of soil water as a...
Fault zone amplified waves as a possible seismic hazard along the Calaveras fault in central California
P. Spudich, K.B. Olsen
2001, Geophysical Research Letters (28) 2533-2536
The Calaveras fault lies within a low velocity zone (LVZ) 1-2 km wide near Gilroy, California. Accelerographs G06, located in the LVZ 1.2 km from the Calaveras fault, and G07, 4 km from G06, recorded both the M 6.2 1984 Morgan Hill and the M 6.9 1989 Loma Prieta earthquakes....
Influence of reactive sulfide (AVS) and supplementary food on Ag, Cd and Zn bioaccumulation in the marine polychaete Neanthes arenaceodentata
J.-S. Lee, B.-G. Lee, H. Yoo, C.-H. Koh, S. N. Luoma
2001, Marine Ecology Progress Series (216) 129-140
A laboratory bioassay determined the relative contribution of various pathways of Ag, Cd and Zn bioaccumulation in the marine polychaete Neanthes arenaceodentata exposed to moderately contaminated sediments. Juvenile worms were exposed for 25 d to experimental sediments containing 5 different reactive sulfide (acid volatile sulfides, AVS) concentrations (1 to 30...
Resolution analysis of finite fault source inversion using one- and three-dimensional Green's functions 2. Combining seismic and geodetic data
D.J. Wald, R.W. Graves
2001, Journal of Geophysical Research B: Solid Earth (106) 8767-8788
Using numerical tests for a prescribed heterogeneous earthquake slip distribution, we examine the importance of accurate Green's functions (GF) for finite fault source inversions which rely on coseismic GPS displacements and leveling line uplift alone and in combination with near-source strong ground motions. The static displacements, while sensitive to the...
Evaluation of flash-flood discharge forecasts in complex terrain using precipitation
D. Yates, T.T. Warner, E.A. Brandes, G.H. Leavesley, Jielun Sun, C.K. Mueller
2001, Journal of Hydrologic Engineering (6) 265-274
Operational prediction of flash floods produced by thunderstorm (convective) precipitation in mountainous areas requires accurate estimates or predictions of the precipitation distribution in space and time. The details of the spatial distribution are especially critical in complex terrain because the watersheds are generally small in size, and small position errors...
Spatial extent of a hydrothermal system at Kilauea Volcano, Hawaii, determined from array analyses of shallow long-period seismicity 2. Results
J. Almendros, B. Chouet, P. Dawson
2001, Journal of Geophysical Research B: Solid Earth (106) 13581-13597
Array data from a seismic experiment carried out at Kilauea Volcano, Hawaii, in February 1997, are analyzed by the frequency-slowness method. The slowness vectors are determined at each of three small-aperture seismic antennas for the first arrivals of 1129 long-period (LP) events and 147 samples of volcanic tremor. The source...
Trends in long-period seismicity related to magmatic fluid compositions
M.M. Morrissey, B. A. Chouet
2001, Journal of Volcanology and Geothermal Research (108) 265-281
Sound speeds and densities are calculated for three different types of fluids: gas-gas mixture; ash-gas mixture; and bubbly liquid. These fluid properties are used to calculate the impedance contrast (Z) and crack stiffness (C) in the fluid-driven crack model (Chouet: J. Geophys. Res., 91 (1986) 13,967; 101 (1988) 4375; A...
Ocean Drilling Program Leg 178 (Antarctic Peninsula): Sedimentology of glacially influenced continental margin topsets and foresets
N. Eyles, J. Daniels, L.E. Osterman, N. Januszczak
2001, Marine Geology (178) 135-156
Ocean Drilling Program Leg 178 (February-April 1998) drilled two sites (Sites 1097 and 1103) on the outer Antarctic Peninsula Pacific continental shelf. Recovered strata are no older than late Miocene or early Pliocene (<4.6 Ma). Recovery at shallow depths in loosely consolidated and iceberg-turbated bouldery sediment was poor but improved...
Creation of residual flows in a partially stratified estuary
M.T. Stacey, J.R. Burau, Stephen G. Monismith
2001, Journal of Geophysical Research C: Oceans (106) 17013-17037
The creation of residual flows in estuaries is examined using acoustic Doppler current profiler data sets from northern San Francisco Bay. The data sets are analyzed using principal component analysis to examine the temporal variability of the flows which create the residual circulation. It is seen that in this periodically...
Comparision between crustal density and velocity variations in Southern California
V.E. Langenheim, E. Hauksson
2001, Geophysical Research Letters (28) 3087-3090
We predict gravity from a three-dimensional Vp model of the upper crust and compare it to the observed isostatic residual gravity field. In general this comparison shows that the isostatic residual gravity field reflects the density variations in the upper to middle crust. Both data sets show similar density variations...
Effective matrix diffusion in kilometer‐scale transport in fractured crystalline rock
Allen M. Shapiro
2001, Water Resources Research (37) 507-522
Concentrations of tritium (3H) and dichlorodifluoromethane (CFC‐12) in water samples taken from glacial drift and fractured crystalline rock over 4 km2 in central New Hampshire are interpreted to identify a conceptual model of matrix diffusion and the magnitude of the diffusion coefficient. Dispersion and mass transfer to and from fractures has...
Quantifying contributions to storm runoff through end-member mixing analysis and hydrologic measurements at the Panola Mountain research watershed (Georgia, USA)
Douglas A. Burns, Jeffery J. McDonnell, R. P. Hooper, N.E. Peters, J.E. Freer, C. Kendall, K. Beven
2001, Hydrological Processes (15) 1903-1924
The geographic sources and hydrologic flow paths of stormflow in small catchments are not well understood because of limitations in sampling methods and insufficient resolution of potential end members. To address these limitations, an extensive hydrologic dataset was collected at a 10 ha catchment at Panola Mountain research watershed near...
Singular spectrum analysis for time series with missing data
D. H. Schoellhamer
2001, Geophysical Research Letters (28) 3187-3190
Geophysical time series often contain missing data, which prevents analysis with many signal processing and multivariate tools. A modification of singular spectrum analysis for time series with missing data is developed and successfully tested with synthetic and actual incomplete time series of suspended-sediment concentration from San Francisco Bay. This method...
Use of radium isotopes to determine the age and origin of radioactive barite at oil-field production sites
R. A. Zielinski, J. K. Otton, J. R. Budahn
2001, Environmental Pollution (113) 299-309
Radium-bearing barite (radiobarite) is a common constituent of scale and sludge deposits that form in oil-field production equipment. The barite forms as a precipitate from radium-bearing, saline formation water that is pumped to the surface along with oil. Radioactivity levels in some oil-field equipment and in soils contaminated by scale...
Magmatic gas scrubbing: Implications for volcano monitoring
R.B. Symonds, T.M. Gerlach, M.H. Reed
2001, Journal of Volcanology and Geothermal Research (108) 303-341
Despite the abundance of SO2(g) in magmatic gases, precursory increases in magmatic SO2(g) are not always observed prior to volcanic eruption, probably because many terrestrial volcanoes contain abundant groundwater or surface water that scrubs magmatic gases until a dry pathway to the atmosphere is established. To better understand scrubbing and...
Upper crustal structure in Puget Lowland, Washington: Results from the 1998 Seismic Hazards Investigation in Puget Sound
T.M. Brocher, T. Parsons, R.J. Blakely, N.I. Christensen, M. A. Fisher, R.E. Wells, Uri S. ten Brink, T. L. Pratt, R. S. Crosson, K. C. Creager, N. P. Symons, L.A. Preston, T. Van Wagoner, K.C. Miller, C.M. Snelson, A.M. Trehu, V.E. Langenheim, G.D. Spence, K. Ramachandran, R.A. Hyndman, D. C. Mosher, B.C. Zelt, C.S. Weaver
2001, Journal of Geophysical Research B: Solid Earth (106) 13541-13564
A new three-dimensional (3-D) model shows seismic velocities beneath the Puget Lowland to a depth of 11 km. The model is based on a tomographic inversion of nearly one million first-arrival travel times recorded during the 1998 Seismic Hazards Investigation in Puget Sound (SHIPS), allowing higher-resolution mapping of subsurface structures...
Estimation of population size using open capture-recapture models
T. L. McDonald, Steven C. Amstrup
2001, Journal of Agricultural, Biological, and Environmental Statistics (6) 206-220
One of the most important needs for wildlife managers is an accurate estimate of population size. Yet, for many species, including most marine species and large mammals, accurate and precise estimation of numbers is one of the most difficult of all research challenges. Open-population capture-recapture models have proven useful in...
Long-term monitoring of creep rate along the Hayward fault and evidence for a lasting creep response to 1989 Loma Prieta earthquake
J. J. Lienkaemper, J.S. Galehouse, R.W. Simpson
2001, Geophysical Research Letters (28) 2265-2268
We present results from over 30 yr of precise surveys of creep along the Hayward fault. Along most of the fault, spatial variability in long-term creep rates is well determined by these data and can help constrain 3D-models of the depth of the creeping zone. However, creep at the south...
