USGS Research Helps the County of Los Angeles Address New Arsenic Standards
James Nickles
2008, Fact Sheet 2008-3043
In January 2006, the U.S. Environmental Protection Agency (USEPA) enacted stringent standards on arsenic in drinking water. The new limitsraised concerns about wells in the Antelope Valley of northern Los Angeles County that had high levels of naturally occurring arsenic. To meet the new standard, Los Angeles County Waterworks District...
Research to More Effectively Manage Critical Ground-Water Basins
James Nickles
2008, Fact Sheet 2008-3037
As the regional management agency for two of the most heavily used ground-water basins in California, the Water Replenishment District of Southern California (WRD) plays a vital role in sheparding the water resources of southern Los Angeles County. WRD is using the results of the U.S. Geological Survey (USGS) studies...
USGS Workshop on Scientific Aspects of a Long-Term Experimental Plan for Glen Canyon Dam, April 10-11, 2007, Flagstaff, Arizona
USGS Grand Canyon Monitoring and Research Center
2008, Open-File Report 2008-1153
Executive Summary Glen Canyon Dam is located in the lower reaches of Glen Canyon National Recreation Area on the Colorado River, approximately 15 miles upriver from Grand Canyon National Park (fig. 1). In 1992, Congress passed and the President signed into law the Grand Canyon Protection Act (GCPA; title XVIII, sec....
Pacific Walrus Response to Arctic Sea Ice Losses
Chadwick V. Jay, Anthony S. Fischbach
2008, Fact Sheet 2008-3041
Sea ice plays an important role in the life of the Pacific walrus (Odobenus rosmarus divergens). U.S. Geological Survey (USGS) scientists are seeking to understand how losses of sea ice during summer over important foraging grounds in the Chukchi Sea will affect walruses. USGS scientists recently modified a remotely deployed...
Questa baseline and pre-mining ground-water quality investigation. 25. Summary of results and baseline and pre-mining ground-water geochemistry, Red River Valley, Taos County, New Mexico, 2001-2005
D. Kirk Nordstrom
2008, Professional Paper 1728
Active and inactive mine sites are challenging to remediate because of their complexity and scale. Regulations meant to achieve environmental restoration at mine sites are equally challenging to apply for the same reasons. The goal of environmental restoration should be to restore contaminated mine sites, as closely as possible, to...
Effects of the H-3 Highway stormwater runoff on the water quality of Halawa Stream, Oahu, Hawaii, November 1998 to August 2004
Reuben H. Wolff, Michael F. Wong
2008, Scientific Investigations Report 2008-5034
Since November 1998, water-quality data have been collected from the H-3 Highway Storm Drain C, which collects runoff from a 4-mi-long viaduct, and from Halawa Stream on Oahu, Hawaii. From January 2001 to August 2004, data were collected from the storm drain and four stream sites in the Halawa Stream...
Effects of supershear rupture speed on the high-frequency content of S waves investigated using spontaneous dynamic rupture models and isochrone theory
A. Bizzarri, Paul A. Spudich
2008, Journal of Geophysical Research Solid Earth (113)
In this paper we achieve three goals: (1) We demonstrate that crack tips governed by friction laws, including slip weakening, rate- and state-dependent laws, and thermal pressurization of pore fluids, propagating at supershear speed have slip velocity functions with reduced high-frequency content compared to crack tips traveling at subshear...
Estimated use of water in the Upper Duck River watershed, central Tennessee, and water-demand projections through 2030
Susan S. Hutson
2008, Scientific Investigations Report 2008-5058
Future municipal water demand was estimated for the Bedford, Coffee, Marshall, and Maury-southern Williamson water-service areas in the upper Duck River watershed in central Tennessee through 2030. The Duck River, a primary source of municipal water, provided a total of 24.3 million gallons per day (Mgal/d) or 92 percent of...
Hydraulic Analyses of Sni-A-Bar Creek and Selected Tributaries at Grain Valley, Jackson County, Missouri
Paul H. Rydlund Jr., William Otero-Benitez, David C. Heimann
2008, Scientific Investigations Report 2008-5051
A study was done by the U.S. Geological Survey, in cooperation with the city of Grain Valley, Jackson County, Missouri, to simulate the hydraulic characteristics of Sni-A-Bar Creek and selected tributaries within the corporate limits. The 10-, 50-, 100-, and 500-year recurrence interval streamflows were simulated to determine potential backwater...
Calculation of the rate of M≥6.5 earthquakes for California and adjacent portions of Nevada and Mexico
Arthur Frankel, Charles Mueller
2008, Open-File Report 2008-1112
One of the key issues in the development of an earthquake recurrence model for California and adjacent portions of Nevada and Mexico is the comparison of the predicted rates of earthquakes with the observed rates. Therefore, it is important to make an accurate determination of the observed rate of M>6.5...
Simulations of Ground-Water Flow, Transport, Age, and Particle Tracking near York, Nebraska, for a Study of Transport of Anthropogenic and Natural Contaminants (TANC) to Public-Supply Wells
Brian R. Clark, Matthew K. Landon, Leon J. Kauffman, George Z. Hornberger
2008, Scientific Investigations Report 2007-5068
Contamination of public-supply wells has resulted in public-health threats and negative economic effects for communities that must treat contaminated water or find alternative water supplies. To investigate factors controlling vulnerability of public-supply wells to anthropogenic and natural contaminants using consistent and systematic data collected in a variety of principal aquifer...
Distribution of Igneous Rocks in Medina and Uvalde Counties, Texas, as Inferred from Aeromagnetic Data
David V. Smith, Robert R. McDougal, Bruce D. Smith, Charles D. Blome
2008, Scientific Investigations Report 2007-5191
A high-resolution aeromagnetic survey was flown in 2001 over Medina and Uvalde Counties, Texas, as part of a multi-disciplinary investigation of the geohydrologic framework of the Edwards aquifer in south-central Texas. The objective of the survey was to assist in mapping structural features that influence aquifer recharge and ground-water flow....
Paleomagnetic study of late Miocene through Pleistocene igneous rocks from the southwestern USA: Results from the historic collections of the U.S. Geological Survey Menlo Park laboratory
Edward A. Mankinen
2008, Geochemistry, Geophysics, Geosystems (9) 1-27
Seventy sites from the southwestern United States provide paleomagnetic results that meet certain minimum criteria and can be considered for the Time‐Averaged Field Initiative (TAFI). The virtual geomagnetic poles for these 70 units are circularly distributed, and their mean is nearly coincident with the rotational axis. When other published data...
Radiative forcing over the conterminous United States due to contemporary land cover land use albedo change
Christopher Barnes, David P. Roy
2008, Geophysical Research Letters (35)
Recently available satellite land cover land use (LCLU) and albedo data are used to study the impact of LCLU change from 1973 to 2000 on surface albedo and radiative forcing for 36 ecoregions covering 43% of the conterminous United States (CONUS). Moderate Resolution Imaging Spectroradiometer (MODIS) snow-free broadband albedo values...
Compilation of surface creep on California faults and comparison of WGCEP 2007 deformation model to Pacific-North American plate Mmtion
Beth A. Wisely, David A. Schmidt, Ray J. Weldon II
2008, Open-File Report 2007-1437-P
This Appendix contains 3 sections that 1) documents published observations of surface creep on California faults, 2) constructs line integrals across the WG-07 deformation model to compare to the Pacific - North America plate motion, and 3) constructs strain tensors of volumes across the WG-07 deformation model to compare to...
Temporal Differences in the Hydrologic Regime of the Lower Platte River, Nebraska, 1895-2006
Daniel Ginting, Ronald B. Zelt, Joshua I. Linard
2008, Scientific Investigations Report 2007-5267
In cooperation with the Lower Platte South Natural Resources District for a collaborative study of the cumulative effects of water and channel management practices on stream and riparian ecology, the U.S. Geological Survey (USGS) compiled, analyzed, and summarized hydrologic information from long-term gaging stations on the lower Platte River to...
Paleoseismic Investigations of the Walnut Site on the San Jacinto Fault
T. E. Fumal, K.J. Kendrick
2008, Open-File Report 2007-1437-O
The Walnut paleoseismic site is located along the northern San Jacinto fault about 3 km southeast of the San Bernardino, California city center (Figures 1, 2). More than 340 meters of trenches were excavated across the fault zone at this site as part of an Alquist-Priolo fault study (Figure 3)....
Cascadia Subduction Zone
Arthur D. Frankel, Mark D. Petersen
2008, Open-File Report 2007-1437-L
The geometry and recurrence times of large earthquakes associated with the Cascadia Subduction Zone (CSZ) were discussed and debated at a March 28-29, 2006 Pacific Northwest workshop for the USGS National Seismic Hazard Maps. The CSZ is modeled from Cape Mendocino in California to Vancouver Island in British Columbia. We include...
Conditional, time-dependent probabilities for segmented Type-A faults in the WGCEP UCERF 2
Edward H. Field, Vipin Gupta
2008, Open-File Report 2007-1437-N
This appendix presents elastic-rebound-theory (ERT) motivated time-dependent probabilities, conditioned on the date of last earthquake, for the segmented type-A fault models of the 2007 Working Group on California Earthquake Probabilities (WGCEP). These probabilities are included as one option in the WGCEP?s Uniform California Earthquake Rupture Forecast 2 (UCERF 2), with...
A-priori rupture models for Northern California Type-A faults
Chris J. Wills, Ray J. Weldon II, Edward H. Field
2008, Open-File Report 2007-1437-K
This appendix describes how a-priori rupture models were developed for the northern California Type-A faults. As described in the main body of this report, and in Appendix G, “a-priori” models represent an initial estimate of the rate of single and multi-segment surface ruptures on each fault. Whether or not a...
Development of final a-fault rupture models for WGCEP/ NSHMP Earthquake Rate Model 2
Edward H. Field, Ray J. Weldon II, Thomas Parsons, Chris J. Wills, Timothy E. Dawson, Ross S. Stein, Mark D. Petersen
2008, Open-File Report 2007-1437-G
This appendix discusses how we compute the magnitude and rate of earthquake ruptures for the seven Type-A faults (Elsinore, Garlock, San Jacinto, S. San Andreas, N. San Andreas, Hayward-Rodgers Creek, and Calaveras) in the WGCEP/NSHMP Earthquake Rate Model 2 (referred to as ERM 2. hereafter). By definition, Type-A faults are...
Spatial seismicity rates and maximum magnitudes for background earthquakes
Mark D. Petersen, Charles S. Mueller, Arthur D. Frankel, Yuehua Zeng
2008, Open-File Report 2007-1437-J
The background seismicity model is included to account for M 5.0 - 6.5 earthquakes on faults and for random M 5.0 ? 7.0 earthquakes that do not occur on faults included in the model (as in earlier models of Frankel et al., 1996, 2002 and Petersen et al., 1996). We...
California fault parameters for the National Seismic Hazard Maps and Working Group on California Earthquake Probabilities 2007
Chris J. Wills, Ray J. Weldon II, W. A. Bryant
2008, Open-File Report 2007-1437-A
This report describes development of fault parameters for the 2007 update of the National Seismic Hazard Maps and the Working Group on California Earthquake Probabilities (WGCEP, 2007). These reference parameters are contained within a database intended to be a source of values for use by scientists interested in producing either...
Recurrence interval and event age data for Type A faults
Timothy E. Dawson, Ray J. Weldon II, Glenn P. Biasi
2008, Open-File Report 2007-1437-B
This appendix summarizes available recurrence interval, event age, and timing of most recent event data for Type A faults considered in the Earthquake Rate Model 2 (ERM 2) and used in the ERM 2 Appendix C analysis as well as Appendix N (time-dependent probabilities). These data have been compiled into...
Earthquake Rate Model 2 of the 2007 working group for California earthquake probabilities, magnitude-area relationships
Ross S. Stein
2008, Open-File Report 2007-1437-D
The Working Group for California Earthquake Probabilities must transform fault lengths and their slip rates into earthquake moment-magnitudes. First, the down-dip coseismic fault dimension, W, must be inferred. We have chosen the Nazareth and Hauksson (2004) method, which uses the depth above which 99% of the background seismicity occurs to...
