Structure of the California Coast Ranges and San Andreas Fault at SAFOD from seismic waveform inversion and reflection imaging
F. Bleibinhaus, J.A. Hole, T. Ryberg, G. S. Fuis
2007, Journal of Geophysical Research B: Solid Earth (112)
[1] A seismic reflection and refraction survey across the San Andreas Fault (SAF) near Parkfield provides a detailed characterization of crustal structure across the location of the San Andreas Fault Observatory at Depth (SAFOD). Steep-dip prestack migration and frequency domain acoustic waveform tomography were applied to...
Quasi-horizontal circulation cells in 3D seawater intrusion
E. Abarca, J. Carrera, X. Sanchez-Vila, Clifford I. Voss
2007, Journal of Hydrology (339) 118-129
The seawater intrusion process is characterized by the difference in freshwater and seawater density that causes freshwater to float on seawater. Many confined aquifers have a large horizontal extension with respect to thickness. In these cases, while buoyancy acts in the vertical direction, flow is confined between the upper and...
Diet and prey selection by Lake Superior lake trout during springs 1986-2001
B.A. Ray, T.R. Hrabik, M.P. Ebener, O. T. Gorman, D.R. Schreiner, S.T. Schram, S.P. Sitar, W.P. Mattes, C.R. Bronte
2007, Journal of Great Lakes Research (33) 104-113
We describe the diet and prey selectivity of lean (Salvelinus namaycush namaycush) and siscowet lake trout (S. n. siscowet) collected during spring (April–June) from Lake Superior during 1986–2001. We estimated prey selectivity by comparing prey numerical abundance estimates from spring bottom trawl surveys and lake trout diet information in similar...
First record of ithytrichia (Trichoptera: Hydroptilidae) in Michigan, U.S.A.
J.M. Craig, M.A. Chriscinske
2007, Entomological News (118) 313-314
[No abstract available]...
Did debris-covered glaciers serve as pleistocene refugia for plants? A new hypothesis derived from observations of recent plant growth on glacier surfaces
T. Fickert, D. Friend, F. Gruninger, B. Molnia, M. Richter
2007, Arctic, Antarctic, and Alpine Research (39) 245-257
This study proposes a new hypothesis: Debris-covered glaciers served as Pleistocene biological refugia. This is based on detailed studies of vascular plant growth on six debris-mantled glaciers, literally around the world, as well as many casual observations also across the globe. We find that such glaciers are quite common and...
Biomarkers of metals exposure in fish from lead-zinc mining areas of Southeastern Missouri, USA
C. J. Schmitt, J.J. Whyte, A.P. Roberts, M.L. Annis, T.W. May, D. E. Tillitt
2007, Ecotoxicology and Environmental Safety (67) 31-47
The potential effects of proposed lead-zinc mining in an ecologically sensitive area were assessed by studying a nearby mining district that has been exploited for about 30 y under contemporary environmental regulations and with modern technology. Blood and liver samples representing fish of three species (largescale stoneroller, Campostoma oligolepis, n=91;...
Estimating hydraulic properties of volcanic aquifers using constant-rate and variable-rate aquifer tests
K. Rotzoll, A. I. El-Kadi, S. B. Gingerich
2007, Journal of the American Water Resources Association (43) 334-345
In recent years the ground-water demand of the population of the island of Maui, Hawaii, has significantly increased. To ensure prudent management of the ground-water resources, an improved understanding of ground-water flow systems is needed. At present, large-scale estimations of aquifer properties are lacking for Maui. Seven analytical methods using...
Luminescence ages for alluvial-fan deposits in Southern Death Valley: Implications for climate-driven sedimentation along a tectonically active mountain front
M.F. Sohn, S. A. Mahan, J.R. Knott, D.D. Bowman
2007, Quaternary International (166) 49-60
Controversy exists over whether alluvial-fan sedimentation along tectonically active mountain fronts is driven by climatic changes or tectonics. Knowing the age of sedimentation is the key to understanding the relationship between sedimentation and its cause. Alluvial-fan deposits in Death Valley and throughout the arid southwestern United States have long been...
Molecular analysis of fungal communities and laccase genes in decomposing litter reveals differences among forest types but no impact of nitrogen deposition
C.B. Blackwood, M. P. Waldrop, D.R. Zak, R. L. Sinsabaugh
2007, Environmental Microbiology (9) 1306-1316
The fungal community of the forest floor was examined as the cause of previously reported increases in soil organic matter due to experimental N deposition in ecosystems producing predominantly high-lignin litter, and the opposite response in ecosystems producing low-lignin litter. The mechanism proposed to explain this phenomenon was that white-rot...
Juvenile densities relative to water regime in mainstem reservoirs of the Tennessee River, USA
L.E. Miranda, D.R. Lowery
2007, Lakes and Reservoirs: Research and Management (12) 87-96
Successful reproduction and development of strong year classes of fish in storage reservoirs are commonly associated with reproductive seasons of high water level and extensive flooding. Responses to flooding are likely to be less pronounced or altogether different in mainstem navigation reservoirs that experience limited water level fluctuation. In these...
Visible and near-infrared multispectral analysis of rocks at Meridiani Planum, Mars, by the Mars Exploration Rover Opportunity
W. H. Farrand, J.F. Bell III, J. R. Johnson, B.L. Jolliff, A.H. Knoll, S. M. McLennan, S. W. Squyres, W. M. Calvin, J.P. Grotzinger, R.V. Morris, J. Soderblom, S.D. Thompson, W.A. Watters, A. S. Yen
2007, Journal of Geophysical Research E: Planets (112)
Multispectral measurements in the visible and near infrared of rocks at Meridiani Planum by the Mars Exploration Rover Opportunity's Pancam are described. The Pancam multispectral data show that the outcrops of the Burns formation consist of two main spectral units which in stretched 673, 535, 432 nm color composites appear...
Winter behavior and ecology of the Alder Flycatcher (Empidonax alnorum) in Peru
M.S. Foster
2007, Ornitologia Neotropical (18) 171-186
The winter ecology and behavior of Alder Flycatchers (Empidonax alnorum) were studied along the Manu, a white-water meander river in Manu National Park, Madre de Dios, Peru?? during October and November, 1993 to 1997. The birds occupied territories in primary-succession habitats on growing point bars. They were most common in...
Fluid chemistry and evolution of hydrothermal fluids in an Archaean transcrustal fault zone network: The case of the Cadillac Tectonic Zone, Abitibi greenstone belt, Canada
P. Neumayr, S.G. Hagemann, D.A. Banks, B.W.D. Yardley, J.-F. Couture, G. P. Landis, R. Rye
2007, Canadian Journal of Earth Sciences (44) 745-773
Detailed fluid geochemistry studies on hydrothermal quartz veins from the Rouyn-Noranda and Val-d'Or areas along the transcrustal Cadillac Tectonic Zone (CTZ) indicate that unmineralized (with respect to gold) sections of the CTZ contained a distinct CO2-dominated, H2S-poor hydrothermal fluid. In contrast, both gold mineralized sections of the CTZ (e.g., at...
USGS assessment of undiscovered oil and gas resources in Paleogene strata of the U.S. Gulf of Mexico coastal plain and state waters
Peter D. Warwick, James L. Coleman, Paul C. Hackley, Daniel O. Hayba, Alexander W. Karlsen, Elisabeth L. Rowan, Sharon M. Swanson
Lorcan Kennan, James Pindell, Norman C. Rosen, editor(s)
2007, Conference Paper, The Paleogene of the Gulf of Mexico and Caribbean basins: Processes, events, and petroleum systems
This report presents a review of the U.S. Geological Survey (USGS) 2007 assessment of the undiscovered oil and gas resources in Paleogene strata underlying the U.S. Gulf of Mexico Coastal Plain and state waters. Geochemical, geologic, geophysical, thermal maturation, burial history, and paleontologic studies have been combined with regional cross...
Regression models for estimating coseismic landslide displacement
R.W. Jibson
2007, Engineering Geology (91) 209-218
Newmark's sliding-block model is widely used to estimate coseismic slope performance. Early efforts to develop simple regression models to estimate Newmark displacement were based on analysis of the small number of strong-motion records then available. The current availability of a much larger set of strong-motion records dictates that these regression...
Desert tortoise hibernation: Temperatures, timing, and environment
K.E. Nussear, T. C. Esque, D.F. Haines, C.R. Tracy
2007, Copeia 378-386
This research examined the onset, duration, and termination of hibernation in Desert Tortoises (Gopherus agassizii) over several years at multiple sites in the northeastern part of their geographic range, and recorded the temperatures experienced by tortoises during winter hibernation. The timing of hibernation by Desert Tortoises differed among sites and...
1400 yr multiproxy record of climate variability from the northern Gulf of Mexico
J.N. Richey, R.Z. Poore, B.P. Flower, T. M. Quinn
2007, Geology (35) 423-426
A continuous decadal-scale resolution record of climate variability over the past 1400 yr in the northern Gulf of Mexico was constructed from a box core recovered in the Pigmy Basin, northern Gulf of Mexico. Proxies include paired analyses of Mg/Ca and δ18O in the white variety of the planktic foraminifer...
Ground water stratification and delivery of nitrate to an incised stream under varying flow conditions
John Karl Bohlke, M. E. O’Connell, K.L. Prestegaard
2007, Journal of Environmental Quality (36) 664-680
Ground water processes affecting seasonal variations of surface water nitrate concentrations were investigated in an incised first-order stream in an agricultural watershed with a riparian forest in the coastal plain of Maryland. Aquifer characteristics including sediment stratigraphy, geochemistry, and hydraulic properties were examined in combination with chemical and isotopic analyses...
The chemical response of particle-associated contaminants in aquatic sediments to urbanization in New England, U.S.A.
A.T. Chalmers, P. C. Van Metre, E. Callender
2007, Journal of Contaminant Hydrology (91) 4-25
Relations between urbanization and particle-associated contaminants in New England were evaluated using a combination of samples from sediment cores, streambed sediments, and suspended stream sediments. Concentrations of PAHs, PCBs, DDT, and seven trace metals (Cd, Cr, Cu, Hg, Ni, Pb, Zn) were correlated strongly with urbanization, with the strongest relations...
Reproductive biology of the brown tree snake, Boiga irregularis (Reptilia: Colubridae), during colonization of Guam and comparison with that in their native range
J. A. Savidge, F.J. Qualls, G.H. Rodda
2007, Pacific Science (61) 191-199
Since their introduction to Guam shortly after World War II, brown tree snakes, Boiga irregularis (Merrem), have seriously impacted the biota and human population of the island. Understanding the biology of this exotic species will likely be important to the success of control programs. We compared the reproductive biology of...
Anthropogenic contaminants as tracers in an urbanizing karst aquifer
B. Mahler, N. Massei
2007, Journal of Contaminant Hydrology (91) 81-106
Karst aquifers are uniquely vulnerable to contamination. In the Barton Springs segment of the karstic Edwards aquifer (Texas, U.S.A.), urban contaminants such as pesticides and volatile organic compounds frequently are detected in spring base flow. To determine whether contaminant concentrations change in response to storms, and if they therefore might...
Quantifying tolerance indicator values for common stream fish species of the United States
M. R. Meador, D.M. Carlisle
2007, Ecological Indicators (7) 329-338
The classification of fish species tolerance to environmental disturbance is often used as a means to assess ecosystem conditions. Its use, however, may be problematic because the approach to tolerance classification is based on subjective judgment. We analyzed fish and physicochemical data from 773 stream sites collected as part of...
Spatial patterns of large natural fires in Sierra Nevada wilderness areas
B.M. Collins, M. Kelly, J. W. van Wagtendonk, S.L. Stephens
2007, Landscape Ecology (22) 545-557
The effects of fire on vegetation vary based on the properties and amount of existing biomass (or fuel) in a forest stand, weather conditions, and topography. Identifying controls over the spatial patterning of fire-induced vegetation change, or fire severity, is critical in understanding fire as a landscape scale process. We...
Self-gravity wake structures in Saturn's a ring revealed by Cassini vims
M.M. Hedman, P. D. Nicholson, H. Salo, B.D. Wallis, B. J. Buratti, K. H. Baines, R. H. Brown, R. N. Clark
2007, Astronomical Journal (133) 2624-2629
During the summer of 2005, the Visual and Infrared Mapping Spectrometer onboard the Cassini spacecraft observed a series of occultations of the star o Ceti (Mira) by Saturn's rings. These observations revealed pronounced variations in the optical depth of the A ring with longitude, which can be attributed to oriented...
Anomalous deepening of a belt of intraslab earthquakes in the Pacific slab crust under Kanto, central Japan: Possible anomalous thermal shielding, dehydration reactions, and seismicity caused by shallower cold slab material
A. Hasegawa, J. Nakajima, S. Kita, T. Okada, T. Matsuzawa, S. H. Kirby
2007, Geophysical Research Letters (34)
[1] A belt of intraslab seismicity in the Pacific slab crust parallel to iso-depth contours of the plate interface has been found beneath Hokkaido and Tohoku. Hypocenter relocations have shown that this seismic belt does not run parallel to but obliquely to the iso-depth contours beneath...
