Accessing northern California earthquake data via Internet
B. Romanowicz, Doug Neuhauser, B.M. Bogaert, David H. Oppenheimer
1994, Eos Science News (75) 257-260
The Northern California Earthquake Data Center (NCEDC) provides easy access to central and northern California digital earthquake data. It is located at the University of California, Berkeley, and is operated jointly with the U.S. Geological Survey (USGS) in Menlo Park, Calif., and funded by the University of California and the...
An assessment of riparian environmental quality by using butterflies and disturbance susceptibility scores
S. Mark Nelson, Douglas C. Andersen
1994, Southwestern Naturalist (39) 137-142
The butterfly community at a revegetated riparian site on the lower Colorado River near Parker, Arizona, was compared to that found in a reference riparian site. Data indicated that the herbaceous plant community, which was lacking at the revegetated site, was important to several butterfly taxa. An index...
The co-seismic slip distribution of the Landers earthquake
J. Freymueller, N.E. King, P. Segall
1994, Bulletin of the Seismological Society of America (84) 646-659
We derived a model for the co-seismic slip distribution on the faults which ruptured during the Landers earthquake sequence of 28 June 1992. The model is based on the inversion of surface geodetic measurements, primarily vector displacements measured using the Global Positioning System (GPS). The inversion procedure assumes...
Triggered seismicity and deformation between the Landers, California, and Little Skull Mountain, Nevada, earthquakes
Paul Bodin, Joan Gomberg
1994, Bulletin of the Seismological Society of America (84) 835-843
This article presents evidence for the channeling of strain energy released by the Ms = 7.4 Landers, California, earthquake within the eastern California shear zone (ECSZ). We document an increase in seismicity levels during the 22-hr period starting with the Landers earthquake and culminating 22 hr later with the...
Fault-zone waves observed at the southern Joshua Tree earthquake rupture zone
S. E. Hough, Y. Ben-Zion, P. Leary
1994, Bulletin of the Seismological Society of America (84) 761-767
Waveform and spectral characteristics of several aftershocks of the M 6.1 22 April 1992 Joshua Tree earthquake recorded at stations just north of the Indio Hills in the Coachella Valley can be interpreted in terms of waves propagating within narrow, low-velocity, high-attenuation, vertical zones. Evidence for our interpretation consists of:...
Magnetic field observations in the near-field the 28 June 1992 Mw 7.3 Landers, California, earthquake
M. J. Johnston, R.J. Mueller, Yoichi Sasai
1994, Bulletin of the Seismological Society of America (84) 792-798
Recent reports suggest that large magnetic field changes occur prior to, and during, large earthquakes. Two continuously operating proton magnetometers, LSBM and OCHM, at distances of 17.3 and 24.2 km, respectively, from the epicenter of the 28 June 1992 Mw 7.3 Landers earthquake, recorded data through the earthquake...
Using regional seismic networks to study the Earth's deep interior
Harley M. Benz, J.E. Vidale, J. Mori
1994, Eos Science News (75) 225-229
Long-period or broadband data from global stations or small aperture arrays have traditionally been used to study the Earth's deep interior. However, recent seismic studies have shown that regional seismic networks can be an important tool in high- resolution studies of the upper mantle, coremantle boundary, and the inner and...
Humic and fulvic acids: sink or source in the availability of metals to the marine bivalves Macoma balthicaand Potamocorbula amurensis?
Alan Decho, Samuel N. Luoma
1994, Marine Ecology Progress Series (108) 133-145
Humic acids (HA) and fulvic acids (FA) are common forms of organic matter in marine sedirnents, and are routinely ingested by deposit- and suspension-feeding animals. These compounds may be a sink for metals, implying that once metals are bound to humic substances they are no longer available to food webs....
Reconnaissance geologic mapping of a portion of the rain‐forest‐covered Guiana Shield, Northwestern Brazil, using SIR-B and digital aeromagnetic data
Fernando Pellon de Miranda, Anne E. McCafferty, James V. Taranik
1994, Geophysics (59) 733-743
This paper documents the result of an integrated analysis of spaceborne radar (SIR-B) and digital aeromagnetic data carried out in the heavily forested Guiana Shield. The objective of the research is to interpret the geophysical data base to its limit to produce a reconnaissance geologic map as an aid to...
Surface energy balance estimates at local and regional scales using optical remote sensing from an aircraft platform and atmospheric data collected over semiarid rangelands
William P. Kustas, M. S. Moran, K.S. Humes, D.I. Stannard, P. J. Pinter Jr., L.E. Hipps, E. Swiatek, D.C. Goodrich
1994, Water Resources Research (30) 1241-1259
Remotely sensed data in the visible, near-infrared, and thermal-infrared wave bands were collected from a low-flying aircraft during the Monsoon '90 field experiment. Monsoon '90 was a multidisciplinary experiment conducted in a semiarid watershed. It had as one of its objectives the quantification of hydrometeorological fluxes during the...
Use of ground-based remotely sensed data for surface energy balance evaluation of a semiarid rangeland
M. S. Moran, William P. Kustas, A. Vidal, D.I. Stannard, J.H. Blanford, W. D. Nichols
1994, Water Resources Research (30) 1339-1349
An interdisciplinary field experiment was conducted to study the water and energy balance of a semiarid rangeland watershed in southeast Arizona during the summer of 1990. Two subwatersheds, one grass dominated and the other shrub dominated, were selected for intensive study with ground-based remote sensing systems and hydrometeorological instrumentation. Surface...
Crustal structure and composition of the southern Foothills Metamorphic Belt, Sierra Nevada, California, from seismic data
Kate Miller, Walter D. Mooney
1994, Journal of Geophysical Research B: Solid Earth (99) 6865-6880
The Foothills Metamorphic Belt is an accreted terrane consisting of Paleozoic and Mesozoic metamorphic rocks that separates the Great Valley from the Sierra Nevada batholith in northern and central California. Until recently, the only available geophysical data for this area were reconnaissance refraction surveys, and gravity and...
Pesticides detected in surface waters and fish of the Red River of the North drainage basin
Mark E. Brigham
1994, Conference Paper, North Dakota Water Quality Symposium Proceedings
The Red River of the North drainage basin (herein referred to as Red River Basin) within the United States is a study unit under the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) program. The overall goals of this program, initiated to better define the status and trends of the...
Drainage investment and wetland loss: an analysis of the national resources inventory data
Aaron J. Douglas, Richard L. Johnson
1994, Journal of Environmental Management (40) 341-355
The United States Soil Conservation Service (SCS) conducts a survey for the purpose of establishing an agricultural land use database. This survey is called the National Resources Inventory (NRI) database. The complex NRI land classification system, in conjunction with the quantitative information gathered by the survey, has numerous applications. The...
Identification of tire leachate toxicants and a risk assessment of water quality effects using tire reefs in canals
S. M. Nelson, G. Mueller, D. C. Hemphill
1994, Bulletin of Environmental Contamination and Toxicology (52) 574-581
Cover is an important component of aquatic habitat and fisheries management. Fisheries biologists often try to improve habitats through the addition of natural and artificial material to improve cover diversity and complexity. Habitat-improvement programs range from submerging used Christmas trees to more complex programs using sophisticated artificial habitat...
Implications of felt area-magnitude relations for earthquake scaling and the average frequency of perceptible ground motion
Arthur Frankel
1994, Bulletin of the Seismological Society of America (84) 462-465
Observed relations between felt area and moment magnitude M for stable continental regions (SCR) and California earthquakes can be explained by a simple model with geometrical spreading, attenuation (Q−1), and earthquake stress drops that remain constant from M 4 to 8. Differences in the slopes of the observed felt...
Evidence for an upper mantle low velocity zone beneath the southern Basin and Range-Colorado Plateau transition zone
H.M. Benz, J. McCarthy
1994, Geophysical Research Letters (21) 509-512
A 370-km-long seismic refraction/wide-angle reflection profile recorded during the Pacific to Arizona Crustal Experiment (PACE) detected an upper mantle P-wave low-velocity zone (LVZ) in the depth range 40 to 55 km beneath the Basin and Range in southern Arizona. Interpretation of seismic data places constraints on the sub-crustal lithosphere of...
Identification of kin structure among Guam rail founders: A comparison of pedigrees and DNA profiles
Susan M. Haig, J.D. Ballou, N.J. Casna
1994, Molecular Ecology (3) 109-119
Kin structure among founders can have a significant effect on subsequent population structure. Here we use the correlation between DNA profile similarity and relatedness calculated from pedigrees to test hypotheses regarding kin structure among founders to the captive Guam rail (Rallus owstoni) population. Five different pedigrees were generated under the...
Modeling of soil water retention from saturation to oven dryness
Cinzia Rossi, John R. Nimmo
1994, Water Resources Research (30) 701-708
Most analytical formulas used to model moisture retention in unsaturated porous media have been developed for the wet range and are unsuitable for applications in which low water contents are important. We have developed two models that fit the entire range from saturation to oven dryness in a practical and...
Comparison of drilling reports and detailed geophysical analysis of ground-water production in bedrock wells
Frederick Paillet, Russell Duncanson
1994, Groundwater (32) 200-206
The most extensive data base for fractured bedrock aquifers consists of drilling reports maintained by various state agencies. We investigated the accuracy and reliability of such reports by comparing a representative set of reports for nine wells drilled by conventional air percussion methods in granite with a suite of geophysical...
Evaluation of measurement scale using imbibition experiments in volcanic tuffs
Alan L. Flint, Lorraine E. Flint, Kenneth A. Richards
1994, Soil Science Society of America Journal (58) 94-102
A major issue in the site characterization at Yucca Mountain, Nevada, a potential site for a high-level nuclear waste repository, is the relevance of laboratory-scale measurements on cores to field-scale processes, particularly water flow. Calculation of Philip`s sorptivity parameter using imbibition of water into rock was selected as a simple...
How permeable are clays and shales?
C. E. Neuzil
1994, Water Resources Research (30) 145-150
The permeability of argillaceous formations, although rarely measured and poorly understood, is commonly a critical parameter in analyses of subsurface flow. Data now available suggest a regular relation between permeability and porosity in clays and shales and permeabilities that, even at large scales, are significantly lower than usually...
The use of simulation and multiple environmental tracers to quantify groundwater flow in a shallow aquifer
Thomas E. Reilly, Niel Plummer, Patrick J. Phillips, Eurybiades Busenberg
1994, Water Resources Research (30) 421-433
Measurements of the concentrations of chlorofluorocarbons (CFCs), tritium, and other environmental tracers can be used to calculate recharge ages of shallow groundwater and estimate rates of groundwater movement. Numerical simulation also provides quantitative estimates of flow rates, flow paths, and mixing properties of the groundwater system. The environmental tracer techniques...
Regional propagation characteristics and source parameters of earthquakes in northeastern North America
John Boatwright
1994, Bulletin of the Seismological Society of America (84) 1-15
The vertical components of the S wave trains recorded on the Eastern Canadian Telemetered Network (ECTN) from 1980 through 1990 have been spectrally analyzed for source, site, and propagation characteristics. The data set comprises some 1033 recordings of 97 earthquakes whose magnitudes range from M ≈ 3 to 6....
Large-explosive source, wide-recording aperture, seismic profiling on the Columbia Plateau, Washington
Craig M. Jarchow, Rufus D. Catchings, William J. Lutter
1994, Geophysics (59) 259-271
Clear subsurface seismic images have been obtained at low cost on the Columbia Plateau, Washington. The Columbia Plateau is perhaps the most notorious of all 'bad-data' areas because large impedance contrasts in surface flood basalts severely degrade the seismic wavefield. This degradation was mitigated in this study via a large-explosive...
