Ecological observations on the colonial ascidian Didemnum sp. in a New England tide pool habitat
P. C. Valentine, M.R. Carman, D.S. Blackwood, E.J. Heffron
2007, Journal of Experimental Marine Biology and Ecology (342) 109-121
The colonial ascidian Didemnum sp. has colonized northwestern Atlantic coastal habitats from southern Long Island, New York, to Eastport, Maine. It is also present in offshore habitats of the Georges Bank fishing grounds. It threatens to alter fisheries habitats and shellfish aquacultures. Observations in a tide pool at Sandwich, MA from...
Geohydrologic assessment of fractured crystalline bedrock on the southern part of Manhattan, New York, through the use of advanced borehole geophysical methods
F. Stumm, A. Chu, P. K. Joesten, J.W. Lane Jr.
2007, Journal of Geophysics and Engineering (4) 245-252
Advanced borehole-geophysical methods were used to assess the geohydrology of fractured crystalline bedrock in 31 of 64 boreholes on the southern part of Manhattan Island, NY in preparation of the construction of a new water tunnel. The study area is located in a highly urbanized part of New York City....
Free zinc ion and dissolved orthophosphate effects on phytoplankton from Coeur d'Alene Lake, Idaho
James S. Kuwabara, Brent R. Topping, Paul F. Woods, James L. Carter
2007, Environmental Science & Technology (41) 2811-2817
Coeur d'Alene Lake in northern Idaho is fed by two major rivers: the Coeur d'Alene River from the east and the St. Joe River from the south, with the Spokane River as its outlet to the north. This phosphorus-limited lake has been subjected to decades of mining (primarily for zinc...
Cycles of hurricane landfalls on the eastern United States linked to changes in Atlantic sea-surface temperatures
Richard Z. Poore, Terry Quinn, Julie Richey, Jackie L. Smith
2007, Circular 1306-2A
The occurrence of hurricane landfalls on the United States may be related to alternating intervals of persistent above-average and below-average surface temperature of the North Atlantic Ocean. The cycle of temperature variations, known as the Atlantic Multidecadal Oscillation (AMO), has been identified by study of records based on thermometer readings...
Landward and eastward shift of Alaskan polar bear denning associated with recent sea ice changes
Anthony S. Fischbach, Steven C. Amstrup, David C. Douglas
2007, Polar Biology (30) 1395-1405
Polar bears (Ursus maritimus) in the northern Alaska region den in coastal areas and on offshore drifting ice. We evaluated changes in the distribution of polar bear maternal dens between 1985 and 2005, using satellite telemetry. We determined the distribution of maternal dens occupied by 89 satellite collared female polar...
Effects of highway construction on sediment and benthic macroinvertebrates in two tributaries of the Lost River, West Virginia
Lara B. Hedrick, S.A. Welsh, James T. Anderson
2007, Journal of Freshwater Ecology (22) 561-569
During a three-year study of two tributaries being crossed by a four-lane highway under construction in the eastern panhandle of West Virginia, we found little difference in the amount of fine sediment collected at upstream and downstream sites. The downstream site on one tributary collected significantly greater amounts of sediment...
A biological assessment of streams in the eastern United States using a predictive model for macroinvertebrate assemblages
D.M. Carlisle, M. R. Meador
2007, Journal of the American Water Resources Association (43) 1194-1207
A predictive model (RIVPACS-type) for benthic macroinvertebrates was constructed to assess the biological condition of 1,087 streams sampled throughout the eastern United States from 1993-2003 as part of the U.S. Geological Survey's National Water-Quality Assessment Program. A subset of 338 sites was designated as reference quality, 28 of which were...
Intertidal sand body migration along a megatidal coast, Kachemak Bay, Alaska
P.N. Adams, P. Ruggiero, G.C. Schoch, G. Gelfenbaum
2007, Journal of Geophysical Research F: Earth Surface (112)
[1] Using a digital video-based Argus Beach Monitoring System (ABMS) on the north shore of Kachemak Bay in south central Alaska, we document the timing and magnitude of alongshore migration of intertidal sand bed forms over a cobble substrate during a 22-month observation period. Two...
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...
Assessment of contamination from arsenical pesticide use on orchards in the great valley region, Virginia and West Virginia, USA
Gilpin R. Robinson Jr., Peter Larkins, Carol J. Boughton, Bradley W. Reed, Philip L. Sibrell
2007, Journal of Environmental Quality (36) 654-663
Lead arsenate pesticides were widely used in apple orchards from 1925 to 1955. Soils from historic orchards in four counties in Virginia and West Virginia contained elevated concentrations of As and Pb, consistent with an arsenical pesticide source. Arsenic concentrations in approximately 50% of the orchard site soils and approximately...
Survey trends of North American shorebirds: Population declines or shifting distributions?
Jonathan Bart, Stephen Brown, Brian A. Harrington, R.I. Guy Morrison
2007, Journal of Avian Biology (38) 73-82
We analyzed data from two surveys of fall migrating shorebirds in central and eastern North America to estimate annual trends in means per survey and to determine whether trends indicate a change in population size or might have been caused by other factors. The analysis showed a broad decline in...
Pattern and potential causes of White-faced Ibis, Plegadis chihi, establishment in the northern prairie and parkland region of North America
Jill A. Shaffer, Gregory A. Knutsen, Ron E. Martin, Joel S. Brice
2007, Canadian Field-Naturalist (121) 46-56
The Northern Prairie and Parkland Waterbird Conservation Plan calls for renewed attention to determining the current status of waterbird populations, their distributions, and conservation needs. It highlights the need for baseline information on the White-faced Ibis (Plegadis chihi). In response, we examined the historical and current distribution of the ibis...
Crustal controls on magmatic-hydrothermal systems: A geophysical comparison of White River, Washington, with Goldfield, Nevada
R.J. Blakely, D. A. John, S. E. Box, B. R. Berger, R.J. Fleck, R. P. Ashley, G.R. Newport, G.R. Heinemeyer
2007, Geosphere (3) 91-107
The White River altered area, Washington, and the Goldfield mining district, Nevada, are nearly contemporaneous Tertiary (ca. 20 Ma) calc-alkaline igneous centers with large exposures of shallow (<1 km depth) magmatic-hydrothermal, acid-sulfate alteration. Goldfield is the largest known high-sulfidation gold deposit in North...
Comparative performance of invasive and native Celastrus species across environmental gradients
S. A. Leicht-Young, J. A. Silander Jr., A.M. Latimer
2007, Oecologia (154) 273-282
The ability to understand and predict the success of invasive plant species in their new ranges is increased when there is a sympatric native congener available for comparison. Celastrus orbiculatus (oriental bittersweet) is a liana introduced into the United States in the mid-1800s from East Asia as an ornamental plant....
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...
Detrital mineral chronology of the Uinta Mountain Group: Implications for the Grenville flood in southwestern Laurentia
P.A. Mueller, D.A. Foster, D.W. Mogk, J. L. Wooden, George D. Kamenov, J.J. Vogl
2007, Geology (35) 431-434
Numerous studies have shown that large quantities of Grenville-age detritus dominate Neoproterozoic to Cambrian arenites in southwest Laurentia (southwestern United States). U-Pb ages and Hf isotopic compositions of zircons and 40Ar/39Ar ages of white mica from clastic sedimentary rocks of the Neoproterozoic Uinta Mountain...
Upper cretaceous microbial petroleum systems in north-central Montana
Paul G. Lillis
2007, Mountain Geologist (44) 11-35
Cenomanian to Campanian rocks of north-central Montana contain shallow economic accumulations of dry natural gas derived from microbial methanogenesis. The methanogens utilized carbon dioxide derived from organic matter in the marginal marine sediments and hydrogen from in situ pore water to generate methane. The most recent USGS assessment of the shallow...
Two lithospheric profiles across southern California derived from gravity and seismic data
T. Romanyuk, Walter D. Mooney, Shane T. Detweiler
2007, Journal of Geodynamics (43) 274-307
We present two detailed 2-D density transects for the crust and uppermost mantle across southern California using a linear gravity inversion technique. This technique parameterizes the crust and upper mantle as a set of blocks that are based on published geologic and seismic...
A genetic assessment of the recovery units for the mojave population of the desert tortoise, Gopherus agassizii
R. W. Murphy, K.H. Berry, T. Edwards, A.M. McLuckie
2007, Chelonian Conservation and Biology (6) 229-251
In the 1994 Recovery Plan for the Mojave population of the desert tortoise, Gopherus agassizii, the US Fish and Wildlife Service established 6 recovery units by using the best available data on habitat use, behavior, morphology, and genetics. To further assess the validity of the recovery units, we analyzed genetic...
Fault locking, block rotation and crustal deformation in the Pacific Northwest
Robert McCaffrey, Anthony I. Qamar, Robert W. King, Ray E. Wells, G. Khazaradze, C.A. Williams, C.W. Stevens, J.J. Vollick, P.C. Zwick
2007, Geophysical Journal International (169) 1315-1340
We interpret Global Positioning System (GPS) measurements in the northwestern United States and adjacent parts of western Canada to describe relative motions of crustal blocks, locking on faults and permanent deformation associated with convergence between the Juan de Fuca and North American plates. To estimate angular velocities of the...
Estimating the amount of eroded section in a partially exhumed basin from geophysical well logs: An example from the North Slope
W. Matthew Burns, Daniel O. Hayba, Elisabeth L. Rowan, David W. Houseknecht
2007, Professional Paper 1732-D
The reconstruction of burial and thermal histories of partially exhumed basins requires an estimation of the amount of erosion that has occurred since the time of maximum burial. We have developed a method for estimating eroded thickness by using porosity-depth trends derived from borehole sonic logs of wells in the...
Influence of groundwater pumping on streamflow restoration following upstream dam removal
James E. Constantz, Hedeff I. Essaid
2007, Hydrological Processes (21) 2823-2834
We compared streamflow in basins under the combined impacts of an upland dam and groundwater pumping withdrawals, by examining streamflow in the presence and absence of each impact. As a qualitative analysis, inter-watershed streamflow comparisons were performed for several rivers flowing into the east side...
Seismic amplification within the Seattle Basin, Washington State: Insights from SHIPS seismic tomography experiments
C.M. Snelson, T.M. Brocher, K.C. Miller, T. L. Pratt, A.M. Trehu
2007, Bulletin of the Seismological Society of America (97) 1432-1448
Recent observations indicate that the Seattle sedimentary basin, underlying Seattle and other urban centers in the Puget Lowland, Washington, amplifies long-period (1-5 sec) weak ground motions by factors of 10 or more. We computed east-trending P- and S-wave velocity models across the Seattle basin from Seismic Hazard Investigations of Puget...
Reinterpretation of Paleoproterozoic accretionary boundaries of the north-central United States based on a new aeromagnetic-geologic compilation
D.K. Holm, R. Anderson, Terrence Boerboom, W.F. Cannon, V. Chandler, M. Jirsa, J. Miller, D.A. Schneider, K. J. Schulz, W. R. Van Schmus
2007, Precambrian Research (157) 71-79
The Paleoproterozoic crust in the north-central U.S. represents intact juvenile terranes accreted to the rifted Archean Superior craton. A new tectonic province map, based on the interpretation of a new aeromagnetic compilation, published geologic maps, and recent geochronologic data, shows progressive accretion of juvenile arc terranes from ca. 1900-1600 Ma....
Post-middle Miocene origin of modern landforms in the eastern Piedmont of Virginia
Robert E. Weems, Lucy E. Edwards
2007, Stratigraphy (4) 35-48
Diverse late middle Miocene dinoflagellate floras, obtained from two sites along the western edge of the Atlantic Coastal Plain in central Virginia, indicate that the eastern Virginia Piedmont was covered by marine waters about 12-13 Ma. This transgression extended farther westward across the Virginia Piedmont than any other transgression that...
