Three-dimensional compressional wavespeed model, earthquake relocations, and focal mechanisms for the Parkfield, California, region
C. Thurber, H. Zhang, F. Waldhauser, J. Hardebeck, A. Michael, D. Eberhart-Phillips
2006, Bulletin of the Seismological Society of America (96)
We present a new three-dimensional (3D) compressional vvavespeed (V p) model for the Parkfield region, taking advantage of the recent seismicity associated with the 2003 San Simeon and 2004 Parkfield earthquake sequences to provide increased model resolution compared to the work of Eberhart-Phillips and Michael (1993) (EPM93). Taking the EPM93...
The importance of adjusting for trip purpose in regional economic analyses of tourist destinations
J. Loomis, L. Caughlan
2006, Tourism Economics (12) 33-43
This paper investigates the empirical importance of distinguishing visitors and their expenditures by trip purpose when estimating the tourism effects of a national park on a local economy. Accounting for trip purpose is quite important when there are two or more nearby major attractions in the same geographical area. This...
Autumn migration and selection of rock crevices as hibernacula by big brown bats in Colorado
D.J. Neubaum, T. J. O'Shea, K.R. Wilson
2006, Journal of Mammalogy (87) 470-479
Movements, distribution, and roosting requirements of most species of temperate-zone bats in autumn are poorly understood. We conducted the 1st radiotelemetry study of autumn migrations and prehibernation roost selection of bats in western North America. Big brown bats (Eptesicus fuscus, n = 55) in the Poudre River watershed, Colorado, moved...
Factors affecting the toxicity of methylmercury injected into eggs
G. H. Heinz, D. J. Hoffman, S. L. Kondrad, C. A. Erwin
2006, Archives of Environmental Contamination and Toxicology (50) 264-279
We developed a standardized protocol for comparing the sensitivities of the embryos of different bird species to methylmercury when methylmercury was injected into their eggs. During the course of developing this protocol, we investigated the effects of various factors on the toxicity of the injected methylmercury. Most of our experiments...
Interpreting the spatio-temporal patterns of sea turtle strandings: Going with the flow
K.M. Hart, P. Mooreside, L.B. Crowder
2006, Biological Conservation (129) 283-290
Knowledge of the spatial and temporal distribution of specific mortality sources is crucial for management of species that are vulnerable to human interactions. Beachcast carcasses represent an unknown fraction of at-sea mortalities. While a variety of physical (e.g., water temperature) and biological (e.g., decomposition) factors as well as the distribution...
Interaction Assessment: A modeling tool for predicting population dynamics from field data
John M. Emlen, Jeffrey J. Duda, Matt D. Kirchhoff, D. Carl Freeman
2006, Ecological Modelling (192) 557-570
Interaction Assessment (INTASS) is a field and analytic methodology for constructing population dynamics models. Because data collected in generating a model for one species comprise much of the information needed for other species, a small increase in effort can result in simultaneous expressions for the dynamics of multiple species. These...
Gas-water-rock interactions in sedimentary basins: CO2 sequestration in the Frio Formation, Texas, USA
Y.K. Kharaka, D.R. Cole, J.J. Thordsen, E. Kakouros, H.S. Nance
2006, Journal of Geochemical Exploration (89) 183-186
To investigate the potential for the geologic storage of CO2 in saline sedimentary aquifers, 1600??ton of CO2 were injected at ???1500 m depth into a 24-m sandstone section of the Frio Formation - a regional reservoir in the US Gulf Coast. Fluid samples obtained from the injection and observation wells...
Impacts of the 2004 tsunami on groundwater resources in Sri Lanka
Tissa H. Illangasekare, Scott W. Tyler, T. Prabhakar Clement, Karen G. Villholth, A.P.G.R.L. Perera, Jayantha Obeysekera, Ananda Gunatilaka, C.R. Panabokke, David W. Hyndman, Kevin J. Cunningham, Jagath J. Kaluarachchi, William W.-G. Yeh, Martinus T. van Van Genuchten, Karsten H. Jensen
2006, Water Resources Research (42)
The 26 December 2004 tsunami caused widespread destruction and contamination of coastal aquifers across southern Asia. Seawater filled domestic open dug wells and also entered the aquifers via direct infiltration during the first flooding waves and later as ponded seawater infiltrated through the permeable sands that are typical of coastal...
Submarine geology of Hana Ridge and Haleakala Volcano's northeast flank, Maui
Barry W. Eakins, Joel E. Robinson
2006, Journal of Volcanology and Geothermal Research (151) 229-250
We present a morphostructural analysis of the submarine portions of Haleakala Volcano and environs, based upon a 4-year program of geophysical surveys and submersible explorations of the underwater flanks of Hawaiian volcanoes that was conducted by numerous academic and governmental research organizations in Japan and the U.S. and funded primarily...
Chemical loading into surface water along a hydrological, biogeochemical, and land use gradient: A holistic watershed approach
L. B. Barber, S.F. Murphy, P. L. Verplanck, Mark W. Sandstrom, Howard E. Taylor, E. T. Furlong
2006, Environmental Science & Technology (40) 475-486
Identifying the sources and impacts of organic and inorganic contaminants at the watershed scale is a complex challenge because of the multitude of processes occurring in time and space. Investigation of geochemical transformations requires a systematic evaluation of hydrologic, landscape, and anthropogenic factors. The 1160 km2 Boulder Creek...
Altitude and configuration of the potentiometric surface in East Nottingham and West Nottingham Townships, Chester County, Pennsylvania, April through June 2004
Lindsay B. Hale
2006, Scientific Investigations Map 2911
Since 1984, the U.S. Geological Survey (USGS) has been mapping the altitude and configuration of the potentiometric surface in Chester County as part of an ongoing cooperative program to measure and describe the water resources of the county. Areas where the potentiometric surface has been mapped are shown on figure...
Age constraints on felsic intrusions, metamorphism and gold mineralisation in the Palaeoproterozoic Rio Itapicuru greenstone belt, NE Bahia State, Brazil
E.F. Mello, R.P. Xavier, N.J. McNaughton, S.G. Hagemann, I. Fletcher, L. Snee
2006, Mineralium Deposita (40) 849-866
U-Pb sensitive high resolution ion microprobe mass spectrometer (SHRIMP) ages of zircon, monazite and xenotime crystals from felsic intrusive rocks from the Rio Itapicuru greenstone belt show two development stages between 2,152 and 2,130 Ma, and between 2,130 and 2,080 Ma. The older intrusions yielded ages of 2,152??6 Ma in...
Abundance of adult saugers across the Wind River watershed, Wyoming
C.J. Amadio, W.A. Hubert, Kevin Johnson, D. Oberlie, D. Dufek
2006, North American Journal of Fisheries Management (26) 156-162
The abundance of adult saugers Sander canadensis was estimated over 179 km of continuous lotic habitat across a watershed on the western periphery of their natural distribution in Wyoming. Three-pass depletions with raft-mounted electrofishing gear were conducted in 283 pools and runs among 19 representative reaches totaling 51 km during...
Atmospheric dust in modern soil on aeolian sandstone, Colorado Plateau (USA): Variation with landscape position and contribution to potential plant nutrients
Richard L. Reynolds, J. Neff, Marith C. Reheis, Paul J. Lamothe
2006, Geoderma (130) 108-123
Rock-derived nutrients in soils originate from both local bedrock and atmospheric dust, including dust from far-distant sources. Distinction between fine particles derived from local bedrock and from dust provides better understanding of the landscape-scale distribution and abundance of soil nutrients. Sandy surficial deposits over dominantly sandstone substrates, covering vast upland...
Kinetics of sorption and abiotic oxidation of arsenic(III) by aquifer materials
A. Amirbahman, D.B. Kent, G.P. Curtis, J.A. Davis
2006, Geochimica et Cosmochimica Acta (70) 533-547
The fate of arsenic in groundwater depends largely on its interaction with mineral surfaces. We investigated the kinetics of As(III) oxidation by aquifer materials collected from the USGS research site at Cape Cod, MA, USA, by conducting laboratory experiments. Five different solid samples with similar specific surface areas (0.6–0.9 m2 g−1) and...
Provenance, age, and environment of mid-Wisconsinan slackwater lake sediment in the St. Louis Metro East area, USA
B. Brandon Curry, D.A. Grimley
2006, Quaternary Research (65) 108-122
Valleys tributary to the Mississippi River contain fossiliferous slackwater lake sediment (Equality Formation) deposited in response to aggradation of the Mississippi River valley during the last glaciation. In the St. Louis Metro East area, the lower part of the Equality Formation is primarily laminated, fossiliferous silt and clay deposited from...
A component-resampling approach for estimating probability distributions from small forecast ensembles
M. Dettinger
2006, Climatic Change (76) 149-168
In many meteorological and climatological modeling applications, the availability of ensembles of predictions containing very large numbers of members would substantially ease statistical analyses and validations. This study describes and demonstrates an objective approach for generating large ensembles of "additional" realizations from smaller ensembles, where the additional ensemble members share...
Toward resolving an earthquake ground motion mystery in west Seattle, Washington State: Shallow seismic focusing may cause anomalous chimney damage
W. J. Stephenson, A.D. Frankel, J. K. Odum, R. A. Williams, T. L. Pratt
2006, Geophysical Research Letters (33)
A shallow bedrock fold imaged by a 1.3-km long high-resolution shear-wave seismic reflection profile in west Seattle focuses seismic waves arriving from the south. This focusing may cause a pocket of amplified ground shaking and the anomalous chimney damage observed in earthquakes of 1949, 1965 and 2001. The 200-m bedrock...
Does the Great Valley Group contain Jurassic strata? Reevaluation of the age and early evolution of a classic forearc basin
K.D. Surpless, S.A. Graham, J.A. Covault, J. L. Wooden
2006, Geology (34) 21-24
The presence of Cretaceous detrital zircon in Upper Jurassic strata of the Great Valley Group may require revision of the lower Great Valley Group chronostratigraphy, with significant implications for the Late Jurassic-Cretaceous evolution of the continental margin. Samples (n = 7) collected from 100 km along strike in the purported...
Denitrification potential in stream sediments impacted by acid mine drainage: Effects of pH, various electron donors, and iron
J.L. Baeseman, R. L. Smith, J. Silverstein
2006, Microbial Ecology (51) 232-241
Acid mine drainage (AMD) contaminates thousands of kilometers of stream in the western United States. At the same time, nitrogen loading to many mountain watersheds is increasing because of atmospheric deposition of nitrate and increased human use. Relatively little is known about nitrogen cycling in acidic, heavy-metal-laden streams; however,...
Comparison of COSPEC and two miniature ultraviolet spectrometer systems for SO2 measurements using scattered sunlight
Tamar Elias, A. Jeff Sutton, Clive Oppenheimer, Keith A. Horton, Harold Garbeil, Vitchko Tsanev, Andrew J.S. McGonigle, Glyn Williams-Jones
2006, Bulletin of Volcanology (68) 313-322
The correlation spectrometer (COSPEC), the principal tool for remote measurements of volcanic SO2, is rapidly being replaced by low-cost, miniature, ultraviolet (UV) spectrometers. We compared two of these new systems with a COSPEC by measuring SO2 column amounts at Kīlauea Volcano, Hawaii. The two systems, one calibrated using in-situ SO2 cells, and...
Minding the gap: Frequency of indels in mtDNA control region sequence data and influence on population genetic analyses
John M. Pearce
2006, Molecular Ecology (15) 333-341
Insertions and deletions (indels) result in sequences of various lengths when homologous gene regions are compared among individuals or species. Although indels are typically phylogenetically informative, occurrence and incorporation of these characters as gaps in intraspecific population genetic data sets are rarely discussed. Moreover, the impact of gaps on estimates...
Mineralogy and arsenic mobility in arsenic-rich Brazilian soils and sediments
de Mello, William R. Roy, J.L. Talbott, J.W. Stucki
2006, Journal of Soils and Sediments (6) 9-19
Background. Soils and sediments in certain mining regions of Brazil contain an unusually large amount of arsenic (As), which raises concerns that mining could promote increased As mobility, and thereby increase the risks of contaminating water supplies. Objectives. The purpose of t his study was to identify the most important...
Direct effects of soil amendments on field emergence and growth of the invasive annual grass Bromus tectorum L. and the native perennial grass Hilaria jamesii (Torr.) Benth
B.A. Newingham, J. Belnap
2006, Plant and Soil (280) 29-40
Bromus tectorum L. is a non-native, annual grass that has invaded western North America. In SE Utah, B. tectorum generally occurs in grasslands dominated by the native perennial grass, Hilaria jamesii (Torr.) Benth. and rarely where the natives Stipa hymenoides Roem. and Schult. and S. comata Trin. & Rupr. are...
Accurately measuring volcanic plume velocity with multiple UV spectrometers
Glyn Williams-Jones, Keith A. Horton, Tamar Elias, Harold Garbeil, Peter J. Mouginis-Mark, A. Jeff Sutton, Andrew J. L. Harris
2006, Bulletin of Volcanology (68) 328-332
A fundamental problem with all ground-based remotely sensed measurements of volcanic gas flux is the difficulty in accurately measuring the velocity of the gas plume. Since a representative wind speed and direction are used as proxies for the actual plume velocity, there can be considerable uncertainty in reported gas flux...
