Middle to late cenozoic geology, hydrography, and fish evolution in the American Southwest
J.E. Spencer, G.R. Smith, T.E. Dowling
2008, Conference Paper, Special Paper of the Geological Society of America
An evaluation of the poorly understood Cenozoic hydrologic history of the American Southwest using combined geological and biological data yields new insights with implications for tectonic evolution. The Mesozoic Cordilleran orogen next to the continental margin of southwestern North America probably formed the continental divide. Mountain building migrated eastward to...
Comparison of total mercury and methylmercury cycling at five sites using the small watershed approach
J. B. Shanley, Mast M. Alisa, K. Campbell, G. R. Aiken, D. P. Krabbenhoft, R. J. Hunt, J.F. Walker, P. F. Schuster, A. Chalmers, Brent T. Aulenbach, N.E. Peters, M. Marvin-DiPasquale, D. W. Clow, M.M. Shafer
2008, Environmental Pollution (154) 143-154
The small watershed approach is well-suited but underutilized in mercury research. We applied the small watershed approach to investigate total mercury (THg) and methylmercury (MeHg) dynamics in streamwater at the five diverse forested headwater catchments of the US Geological Survey Water, Energy, and...
Temporal trends in nitrate and selected pesticides in mid-atlantic ground water
L.M. Debrewer, S.W. Ator, J. M. Denver
2008, Conference Paper, Journal of Environmental Quality
Evaluating long-term temporal trends in regional ground-water quality is complicated by variable hydrogeologic conditions and typically slow flow, and such trends have rarely been directly measured. Ground-water samples were collected over near-decadal and annual intervals from unconfined aquifers in agricultural areas of the Mid-Atlantic region, including fractured carbonate rocks in...
Decadal-scale changes of nitrate in ground water of the United States, 1988-2004
Michael G. Rupert
2008, Journal of Environmental Quality (37) S240-S248
This study evaluated decadal-scale changes of nitrate concentrations in groundwater samples collected by the USGS National Water-Quality Assessment Program from 495 wells in 24 well networks across the USA in predominantly agricultural areas. Each well network was sampled once during 1988-1995 and resampled once during 2000-2004. Statistical tests of decadal-scale...
Scaling hyporheic exchange and its influence on biogeochemical reactions in aquatic ecosystems
Ben L. O’Connor, Judson W. Harvey
2008, Water Resources Research (44)
Hyporheic exchange and biogeochemical reactions are difficult to quantify because of the range in fluid‐flow and sediment conditions inherent to streams, wetlands, and nearshore marine ecosystems. Field measurements of biogeochemical reactions in aquatic systems are impeded by the difficulty of measuring hyporheic flow simultaneously with chemical gradients in sediments. Simplified...
Talc friction in the temperature range 25°–400 °C: relevance for fault-zone weakening
Diane E. Moore, David A. Lockner
2008, Tectonophysics (449) 120-132
Talc is one of the weakest minerals that is associated with fault zones. Triaxial friction experiments conducted on water-saturated talc gouge at room temperature yield values of the coefficient of friction, μ(shear stress, τ/effective normal stress, σ′N) in the range 0.16–0.23, and μ increases with increasing σ′N. Talc gouge heated to temperatures of 100°–400 °C is...
Monitoring urban impacts on suspended sediment, trace element, and nutrient fluxes within the City of Atlanta, Georgia, USA: Program design, methodological considerations, and initial results
A. J. Horowitz, K. A. Elrick, J.J. Smith
2008, Hydrological Processes (22) 1473-1496
Atlanta, Georgia (City of Atlanta, COA), is one of the most rapidly growing urban areas in the US. Beginning in 2003, the US Geological Survey established a long-term water-quantity/quality monitoring network for the COA. The results obtained during the first 2 years have provided insights into the requirements needed to...
Age and growth of the knobbed whelk Busycon carica (Gmelin 1791) in South Carolina subtidal waters
A.G. Eversole, W.D. Anderson, J. Jeffery Isely
2008, Journal of Shellfish Research (27) 423-426
Knobbed whelk, Busycon carica (Gmelin, 1791), age and growth were estimated using tagged and recaptured individuals (n = 396) from areas off South Carolina coastal islands. Recaptured whelks were at large an average of 298 d (4-2,640 d). Growth, an increase in shell length (SL), was evident in 24% of...
Habitat use and movement patterns by adult saugers from fall to summer in an unimpounded small-river system
K.M. Kuhn, W.A. Hubert, Kevin Johnson, D. Oberlie, D. Dufek
2008, North American Journal of Fisheries Management (28) 360-367
The Little Wind River drainage in Wyoming is a relatively small unimpounded river system inhabited by native saugers Sander canadensis. Radio telemetry was used to assess habitat use and movement patterns by adult saugers in the river system from fall through early summer. Fifty-four adult saugers were captured during fall...
Development and evaluation of geochemical methods for the sourcing of archaeological maize
L. V. Benson, Howard E. Taylor, K.A. Peterson, B.D. Shattuck, C.A. Ramotnik, J.R. Stein
2008, Journal of Archaeological Science (35) 912-921
Strontium (Sr)-isotope values on bone from deer mice pairs from 12 field sites in the Chaco Canyon area, New Mexico, were compared with isotope values of synthetic soil waters from the same fields. The data indicate that mice obtain Sr from near-surface sources and that soil samples collected at depths...
Summer temperature variation and implications for juvenile Atlantic salmon
M. E. Mather, D.L. Parrish, C.A. Campbell, J.R. McMenemy, Joseph M. Smith
2008, Hydrobiologia (603) 183-196
Temperature is important to fish in determining their geographic distribution. For cool- and cold-water fish, thermal regimes are especially critical at the southern end of a species' range. Although temperature is an easy variable to measure, biological interpretation is difficult. Thus, how to determine what temperatures are meaningful to fish...
Early marine growth of pink salmon in Prince William Sound and the coastal gulf of Alaska during years of low and high survival
A.D. Cross, D.A. Beauchamp, K.W. Myers, J.H. Moss
2008, Transactions of the American Fisheries Society (137) 927-939
Although early marine growth has repeatedly been correlated with overall survival in Pacific salmon Oncorhynchus spp., we currently lack a mechanistic understanding of smolt-to-adult survival. Smolt-to-adult survival of pink salmon O. gorbuscha returning to Prince William Sound was lower than average for juveniles that entered marine waters in 2001 and...
Wetlands as principal zones of methylmercury production in southern Louisiana and the Gulf of Mexico region
B.D. Hall, G. R. Aiken, D. P. Krabbenhoft, M. Marvin-DiPasquale, C.M. Swarzenski
2008, Environmental Pollution (154) 124-134
It is widely recognized that wetlands, especially those rich in organic matter and receiving appreciable atmospheric mercury (Hg) inputs, are important sites of methylmercury (MeHg) production. Extensive wetlands in the southeastern United States have many ecosystem attributes ideal for promoting high MeHg production rates; however, relatively few mercury cycling studies...
The effect of variations in relative spectral response on the retrieval of land surface parameters from multiple sources of remotely sensed imagery
D. J. Meyer, G. Chander
2008, Conference Paper, International Geoscience and Remote Sensing Symposium (IGARSS)
Airborne visible infrared imaging spectrometer (AVIRIS) images, collected over Sioux Falls, South Dakota, were used to quantify the effect of spectral response on different surface materials and to develop spectral "figures-of-merit" for spectral responses covering similar, but not identical spectral bands. In this simulation, AVIRIS images...
Chemical weathering of a marine terrace chronosequence, Santa Cruz, California I: Interpreting rates and controls based on soil concentration-depth profiles
A. F. White, M. S. Schulz, D.V. Vivit, A.E. Blum, David A. Stonestrom, S.P. Anderson
2008, Geochimica et Cosmochimica Acta (72) 36-68
The spatial and temporal changes in element and mineral concentrations in regolith profiles in a chronosequence developed on marine terraces along coastal California are interpreted in terms of chemical weathering rates and processes. In regoliths up to 15 m deep and 226 kyrs old, quartz-normalized mass transfer coefficients indicate non-stoichiometric...
Distribution and spawning dynamics of capelin (Mallotus villosus) in Glacier Bay, Alaska: A cold water refugium
Mayumi L. Arimitsu, John F. Piatt, Michael A. Litzow, Alisa A. Abookire, Marc D. Romano, Martin D. Robards
2008, Fisheries Oceanography (17) 137-146
Pacific capelin (Mallotus villosus) populations declined dramatically in the Northeastern Pacific following ocean warming after the regime shift of 1977, but little is known about the cause of the decline or the functional relationships between capelin and their environment. We assessed the distribution and abundance of spawning, non-spawning adult and...
Transport and distribution of trace elements and other selected inorganic constituents by suspended particulates in the Salton Sea Basin, California, 2001
L.A. LeBlanc, R. A. Schroeder
2008, Hydrobiologia (604) 123-135
In order to examine the transport of contaminants associated with river-derived suspended particles in the Salton Sea, California, large volume water samples were collected in transects established along the three major rivers emptying into the Salton Sea in fall 2001. Rivers in this area carry significant aqueous and particulate contaminant...
Abyssal ostracods from the South and Equatorial Atlantic Ocean: Biological and paleoceanographic implications
Moriaki Yasuhara, T. M. Cronin, Arbizu P. Martinez
2008, Deep-Sea Research Part I: Oceanographic Research Papers (55) 490-497
We report the distribution of ostracods from ???5000 m depth from the Southeast and Equatorial Atlantic Ocean recovered from the uppermost 10 cm of minimally disturbed sediments taken by multiple-corer during the R/V Meteor DIVA2 expedition M63.2. Five cores yielded the following major deep-sea genera: Krithe, Henryhowella, Poseidonamicus, Legitimocythere, Pseudobosquetina,...
New global hydrography derived from spaceborne elevation data
B. Lehner, K.L. Verdin, A. Jarvis
2008, Eos, Transactions, American Geophysical Union (89) 93-94
To study the Earth system and to better understand the implications of global environmental change, there is a growing need for large-scale hydrographic data sets that serve as prerequisites in a variety of analyses and applications, ranging from regional watershed and freshwater conservation planning to global hydrological, climate, biogeochemical, and...
Methane-producing microbial community in a coal bed of the Illinois Basin
D. Strapoc, F.W. Picardal, C. Turich, I. Schaperdoth, J. L. Macalady, J.S. Lipp, Y.-S. Lin, T.F. Ertefai, F. Schubotz, K.-U. Hinrichs, Maria Mastalerz, A. Schimmelmann
2008, Applied and Environmental Microbiology (74) 2424-2432
A series of molecular and geochemical studies were performed to study microbial, coal bed methane formation in the eastern Illinois Basin. Results suggest that organic matter is biodegraded to simple molecules, such as H 2 and CO2, which fuel methanogenesis and the generation of large coal bed methane reserves. Small-subunit...
Sandwave migration in Monterey Submarine Canyon, Central California
J. P. Xu, F. L. Wong, R. Kvitek, D.P. Smith, C. K. Paull
2008, Marine Geology (248) 193-212
Repeated high-resolution multibeam bathymetric surveys from 2002 through 2006 at the head of the Monterey Submarine Canyon reveal a sandwave field along the canyon axis between 20 and 250??m water depth. These sandwaves range in wavelength from 20 to 70??m and 1 to 3??m in height. A quantitative measure was...
At-sea distribution of satellite-tracked grey-faced petrels, Pterodroma macroptera gouldi, captured on the Ruamaahua (Aldermen) Islands, New Zealand
Catriona MacLeod, Josh Adams, Phil Lyver
2008, Papers and Proceedings Royal Society of Tasmania (142) 73-88
We used satellite telemetry to determine the at-sea distribution of 32 adult (non-breeders and failed breeders) Grey-faced Petrels, Pterodroma macroptera gouldi, during July-October in 2006 and 2007. Adults captured at breeding colonies on the Ruamaahua (Aldermen) Islands ranged across the southwestern Pacific Ocean and Tasman Sea between 20-49°S and 142°E...
Status of the desert tortoise in Red Rock Canyon State Park
Kristin H. Berry, Kevin Keith, Tracy Y. Bailey
2008, California Fish and Game (94) 98-118
We surveyed for desert tortoises, Gopherus agassizii, in the western part of Red Rock Canyon State Park and watershed in eastern Kern County, California, between 2002 and 2004. We used two techniques: a single demographic plot (~4 km2 ) and 37 landscape plots (1-ha each). We estimated population densities of...
When desert tortoises are rare: Testing a new protocol for assessing status
Kevin Keith, Kristin H. Berry, James F. Weigand
2008, California Fish and Game (94) 75-97
We developed and tested a new protocol for sampling populations of the desert tortoise, Gopherus agassizii, a state- and federally listed species, in areas where population densities are very low, historical data are sparse, and anthropogenic uses may threaten the well-being of tortoise populations and habitat. We conducted a 3-year...
Development of a model to assess ground-water availability in California's Central Valley
Claudia C. Faunt, Randall T. Hanson, Kenneth Belitz
2008, Water Resources Impact (10) 27-30
No abstract available....
