USGS national surveys and analysis projects: Preliminary compilation of integrated geological datasets for the United States: A section in Digital mapping techniques '06 - Workshop proceedings
Suzanne W. Nicholson, Douglas B. Stoeser, Frederic H. Wilson, Connie L. Dicken, Stephen Ludington
2007, Open-File Report 2007-1285
The growth in the use of Geographic Information Systems (GIS) has highlighted the need for regional and national digital geologic maps attributed with age and rock type information. Such spatial data can be conveniently used to generate derivative maps for purposes that include mineral-resource assessment, metallogenic studies, tectonic studies, human...
Effect of river sediment on phosphorus chemistry of similarly aged natural and created wetlands in the Atchafalaya Delta, Louisiana, USA
M.E. Poach, S.P. Faulkner
2007, Journal of Environmental Quality (36) 1217-1223
The goal of wetland creation is to produce an artificial wetland that functions as a natural wetland. Studies comparing created wetlands to similarly aged natural wetlands provide important information about creation techniques and their improvement so as to attain that goal. We hypothesized that differences in sediment phosphorus accretion, deposition,...
Relationship of Caspian tern foraging ecology to nesting success in the Columbia River estuary, Oregon, USA
Scott K. Anderson, D.D. Roby, Donald E. Lyons, K. Collis
2007, Estuarine, Coastal and Shelf Science (73) 447-456
The prevalence of juvenile salmonids (Oncorhynchus spp.) and marine forage fishes in the diet of Caspian terns (Hydroprogne caspia) nesting in the Columbia River estuary has been established, but the relationship between diet composition, foraging distribution, and productivity of these birds has received little attention. We used radio-telemetry and on-colony...
Investigations of adult Lost River, shortnose, and Klamath largescale suckers in Upper Klamath Lake and its tributaries, Oregon. Annual report 2005
P.M. Barry, B.S. Hayes, A.C. Scott, C.D. Luton, E.C. Janney
2007, Report
n/a...
Occurrence and nest survival of four thrush species on a managed central Appalachian forest
R.L. Dellinger, P.B. Wood, P.D. Keyser
2007, Forest Ecology and Management (243) 248-258
The wood thrush (Hylocichla mustelina Gmelin) is a species of concern in the central Appalachians, and is sympatric there with three related species, the American robin (Turdus migratorius Linnaeus), hermit thrush (Catharus guttatus Pallas), and veery (Catharus fuscescens Stephens). Our objectives were to quantify use of mature forests and areas...
Factors influencing ground-water recharge in the eastern United States
B. T. Nolan, R. W. Healy, P.E. Taber, K. Perkins, K.J. Hitt, D.M. Wolock
2007, Journal of Hydrology (332) 187-205
Ground-water recharge estimates for selected locations in the eastern half of the United States were obtained by Darcian and chloride-tracer methods and compared using statistical analyses. Recharge estimates derived from unsaturated-zone (RUZC) and saturated-zone (RSZC) chloride mass balance methods are less variable (interquartile ranges or IQRs are 9.5 and 16.1...
Understanding Merapi-type volcanoes
M.A. Purbawinata, Antonius Ratdomopurbo, Surono, John S. Pallister, B. Luehr, Chris Newhall
2007, Eos, Transactions, American Geophysical Union (88) 5-5
"We have to understand volcano science to know what to monitor.” That simple statement by Antonius Ratdomopurbo, director of the Indonesian Center for Volcano Technology [Balai Penyelidikan dan Pengembangan‐Teknologi (BPPTK)],captured the spirit and content of a recent workshop about Merapi and Merapi‐type volcanoes.Merapi still is experiencing low levels of unrest,...
A field assessment of the value of steady shape hydraulic tomography for characterization of aquifer heterogeneities
Geoffrey C. Bohling, James J. Butler Jr., Xiaoyong Zhan, Michael D. Knoll
2007, Water Resources Research (43)
Hydraulic tomography is a promising approach for obtaining information on variations in hydraulic conductivity on the scale of relevance for contaminant transport investigations. This approach involves performing a series of pumping tests in a format similar to tomography. We present a field‐scale assessment of hydraulic tomography in a porous aquifer,...
Can modeling improve estimation of desert tortoise population densities?
K.E. Nussear, C.R. Tracy
2007, Ecological Applications (17) 579-586
The federally listed desert tortoise (Gopherus agassizii) is currently monitored using distance sampling to estimate population densities. Distance sampling, as with many other techniques for estimating population density, assumes that it is possible to quantify the proportion of animals available to be counted in any census. Because desert tortoises spend...
Holocene evolution of the merrimack embayment, northern massachusetts, interperted from shallow seismic stratigraphy
C.J. Hein, D. M. FitzGerald, W. A. Barnhardt
2007, Conference Paper, Coastal Sediments '07 - Proceedings of 6th International Symposium on Coastal Engineering and Science of Coastal Sediment Processes
Recent multi-beam, backscatter, and bottom sediment data demonstrate that a large sand sheet was formed in the inner shelf by the reworking of the Merrimack River lowstand delta and braid plain (12 kya) during the Holocene transgression. Seismic data reveal the presence of widespread channel cut-and-fill structures landward of the...
Habitat partitioning of four sympatric thrush species at three spatial scales on a managed forest in West Virginia
R.L. Dellinger, P.B. Wood, P.D. Keyser, G. Seidel
2007, The Auk (124) 1425-1438
Four thrush species are sympatric in the central Appalachians: Veery (Catharus fuscescens), Hermit Thrush (C. guttatus), Wood Thrush (Hylocichla mustelina), and American Robin (Turdus migratorius). The four species often nest near one another, which suggests that habitat partitioning may have developed to minimize past interspecific competition. Our objectives were to...
Changes in a population of exotic rainbow smelt in Lake Superior: Boom to bust, 1974-2005
O. T. Gorman
2007, Journal of Great Lakes Research (33) 75-90
Changes in a population of rainbow smelt (Osmerus mordax) in the Apostle Islands region of Lake Superior were chronicled over a 32-yr time series, 1974–2005. At the beginning of the time series, rainbow smelt was the predominant prey species, abundance of lake herring (Coregonis artedi) was very low, and the...
Late Quaternary alluviation and offset along the eastern Big Pine fault, southern California
S.B. DeLong, S.A. Minor, L.J. Arnold
2007, Geomorphology (90) 1-10
Determining late Quaternary offset rates on specific faults within active mountain belts is not only a key component of seismic hazard analysis, but sheds light on regional tectonic development over geologic timescales. Here we report an estimate of dip-slip rate on the eastern Big Pine oblique-reverse fault in the upper...
Cosmogenic 10Be and 36Cl geochronology of offset alluvial fans along the northern Death Valley fault zone: Implications for transient strain in the eastern California shear zone
K.L. Frankel, K.S. Brantley, J.F. Dolan, R.C. Finkel, R.E. Klinger, J.R. Knott, M. N. Machette, L.A. Owen, F. M. Phillips, J. L. Slate, B.P. Wernicke
2007, Journal of Geophysical Research B: Solid Earth (112)
The northern Death Valley fault zone (NDVFZ) has long been recognized as a major right-lateral strike-slip fault in the eastern California shear zone (ECSZ). However, its geologic slip rate has been difficult to determine. Using high-resolution digital topographic imagery and terrestrial cosmogenic nuclide dating, we present the first geochronologically determined...
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;...
Analysis of pumping‐induced unsaturated regions beneath a perennial river
Grace W. Su, James Jasperse, Donald Seymour, James E. Constantz, Quanlin Zhou
2007, Water Resources Research (43)
The presence of an unsaturated region beneath a streambed during groundwater pumping near streams can reduce the pumping capacity, change flow paths, and alter the types of biological transformations in the streambed sediments. A three‐dimensional, multiphase flow model of two horizontal collector wells along the Russian River near Forestville, California,...
New K-Ar ages for calculating end-of-shield extrusion rates at West Maui volcano, Hawaiian island chain
David R. Sherrod, T. Murai, Takahiro Tagami
2007, Bulletin of Volcanology (69) 627-642
Thirty-seven new K–Ar ages from West Maui volcano, Hawai‘i, are used to define the waning stages of shield growth and a brief episode of postshield volcanism. All but two samples from shield-stage strata have reversed polarity magnetization, so conceivably the exposed shield is not much older than the Olduvai Normal-Polarity...
Coupling contaminants with demography: Effects of lead and selenium in Pacific common eiders
H.M. Wilson, Paul L. Flint, A.N. Powell
2007, Environmental Toxicology and Chemistry (26) 1410-1417
We coupled intensive population monitoring with collection of blood samples from 383 nesting Pacific common eiders (Somateria mollisima v-nigrum) at two locations in Alaska (USA) from 2002 to 2004. We investigated annual, geographic, and within-season variation in blood concentrations of lead and selenium; compared exposure patterns with sympatrically nesting spectacled...
Development of a soil conservation standard and guidelines for OHV recreation management in California
T.L. Bedrossian, S.D. Reynolds
2007, Environmental & Engineering Geoscience (13) 241-253
In 2004, the California State Parks (CSP) agency contracted with the California Geological Survey (CGS) to update the 1991 Soil Conservation Guide-lines/Standards for Off-Highway Vehicle (OHV) Recreation Management. Per state legislation, the 1991 standards were updated to establish a generic and measurable standard at least sufficient to allow restoration of...
Modeled impact of anthropogenic land cover change on climate
K.L. Findell, E. Shevliakova, P. C. D. Milly, R.J. Stouffer
2007, Journal of Climate (20) 3621-3634
Equilibrium experiments with the Geophysical Fluid Dynamics Laboratory's climate model are used to investigate the impact of anthropogenic land cover change on climate. Regions of altered land cover include large portions of Europe, India, eastern China, and the eastern United States. Smaller areas of change are present in various tropical...
Annual modulation of seismicity along the San Andreas Fault near Parkfield, CA
L.B. Christiansen, Shaul Hurwitz, Steven E. Ingebritsen
2007, Geophysical Research Letters (34)
We analyze seismic data from the San Andreas Fault (SAF) near Parkfield, California, to test for annual modulation in seismicity rates. We use statistical analyses to show that seismicity is modulated with an annual period in the creeping section of the fault and a semiannual period in the locked section...
Using pebble lithology and roundness to interpret gravel provenance in piedmont fluvial systems of the Rocky Mountains, USA
D. A. Lindsey, W. H. Langer, B. S. Van Gosen
2007, Sedimentary Geology (199) 223-232
Clast populations in piedmont fluvial systems are products of complex histories that complicate provenance interpretation. Although pebble counts of lithology are widely used, the information provided by a pebble count has been filtered by a potentially large number of processes and circumstances. Counts of pebble lithology and roundness together offer...
Revisiting the cape cod bacteria injection experiment using a stochastic modeling approach
Reed M. Maxwell, Claire Welty, Ronald W. Harvey
2007, Environmental Science & Technology (41) 5548-5558
Bromide and resting-cell bacteria tracer tests conducted in a sandy aquifer at the U.S. Geological Survey Cape Cod site in 1987 were reinterpreted using a three-dimensional stochastic approach. Bacteria transport was coupled to colloid filtration theory through functional dependence of local-scale colloid transport parameters upon hydraulic conductivity and seepage velocity...
An exhumed Late Paleozoic canyon in the rocky mountains
G.S. Soreghan, D.E. Sweet, K.R. Marra, C.F. Eble, M. J. Soreghan, R.D. Elmore, S.A. Kaplan, M.D. Blum
2007, Journal of Geology (115) 473-481
Landscapes are thought to be youthful, particularly those of active orogenic belts. Unaweep Canyon in the Colorado Rocky Mountains, a large gorge drained by two opposite-flowing creeks, is an exception. Its origin has long been enigmatic, but new data indicate that it is an exhumed late Paleozoic landform. Its survival...
Detection, attribution, and sensitivity of trends toward earlier streamflow in the Sierra Nevada
E.P. Maurer, I.T. Stewart, Celine Bonfils, P. B. Duffy, D. Cayan
2007, Journal of Geophysical Research D: Atmospheres (112)
Observed changes in the timing of snowmelt dominated streamflow in the western United States are often linked to anthropogenic or other external causes. We assess whether observed streamflow timing changes can be statistically attributed to external forcing, or whether they still lie within the bounds of natural (internal) variability for...
