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...
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...
Why the sacramento delta area differs from other parts of the great valley: numerical modeling of thermal structure and thermal subsidence of forearc basins
V.O. Mikhailov, T. Parsons, R.W. Simpson, E.P. Timoshkina, C. Williams
2007, Izvestiya, Physics of the Solid Earth (43) 75-90
Data on present-day heat flow, subsidence history, and paleotemperature for the Sacramento Delta region, California, have been employed to constrain a numerical model of tectonic subsidence and thermal evolution of forearc basins. The model assumes an oceanic basement with an initial thermal profile dependent on its age subjected to refrigeration...
Spatial and temporal migration patterns of Wilson's Warbler (Wilsonia pusilla) in the southwest as revealed by stable isotopes
K.L. Paxton, Charles van Riper III, T.C. Theimer, E. H. Paxton
2007, The Auk (124) 162-175
We used stable hydrogen isotopes (δD) to identify the breeding locations of Wilson’s Warbler (Wilsonia pusilla) migrating through five sites spanning a cross-section of the species’ southwestern migration route during the springs of 2003 and 2004. Determining the temporal and spatial patterns of migration and degree of population segregation during...
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...
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...
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...
Sea level fluctuations in central California at subtidal to decadal and longer time scales with implications for San Francisco Bay, California
H. F. Ryan, M.A. Noble
2007, Estuarine, Coastal and Shelf Science (73) 538-550
Sea level elevations from near the mouth of San Francisco Bay are used to describe the low-frequency variability of forcing of the coastal ocean on the Bay at a variety of temporal scales. About 90% of subtidal fluctuations in sea level...
A condensed middle Cenomanian succession in the Dakota Sandstone (Upper Cretaceous), Sevilleta National Wildlife Refuge, Socorro County, New Mexico
Stephen C. Hook, William A. Cobban
2007, New Mexico Geology (29) 75-96
The upper part of the Dakota Sandstone exposed on the Sevilleta National Wildlife Refuge, northern Socorro County, New Mexico, is a condensed, Upper Cretaceous, marine succession spanning the first five middle Cenomanian ammonite zones of the U.S. Western Interior. Farther north in New Mexico these five ammonite zones occur over...
A project for monitoring trends in burn severity
Jeffery C. Eidenshink, Brian Schwind, Ken Brewer, Zhu-Liang Zhu, Brad Quayle, Stephen M. Howard
2007, Fire Ecology (3) 3-21
Jeff Eidenshink, Brian Schwind, Ken Brewer, Zhi-Liang Zhu, Brad Quayle, and Elected officials and leaders of environmental agencies need information about the effects of large wildfires in order to set policy and make management decisions. Recently, the Wildland Fire Leadership Council (WFLC), which implements and coordinates the National Fire Plan...
Aeromagnetic mapping of the structure of Pine Canyon caldera and Chisos Mountains intrusion, Big Bend National Park, Texas
B. J. Drenth, C. A. Finn
2007, Geological Society of America Bulletin (119) 1521-1534
Analysis of aeromagnetic and gravity data reveals new details of the structure, igneous geology, and temporal evolution of the prominent, enigmatic ca.32 Ma Pine Canyon caldera and the Chisos Mountains (Big Bend National Park, Texas). The main caldera-filling Pine Canyon Rhyolite, the oldest member of the South Rim Formation, is...
Passive aerobic treatment of net-alkaline, iron-laden drainage from a flooded underground anthracite mine, Pennsylvania, USA
C.A. Cravotta III
2007, Mine Water and the Environment (26) 128-149
This report evaluates the results of a continuous 4.5-day laboratory aeration experiment and the first year of passive, aerobic treatment of abandoned mine drainage (AMD) from a typical flooded underground anthracite mine in eastern Pennsylvania, USA. During 1991-2006, the AMD source, locally known as the Otto Discharge, had flows from...
A cold phase of the East Pacific triggers new phytoplankton blooms in San Francisco Bay
James E. Cloern, Alan D. Jassby, Janet K. Thompson, Kathryn Hieb
2007, Proceedings of the National Academy of Sciences of the United States of America (104) 18561-18565
Ecological observations sustained over decades often reveal abrupt changes in biological communities that signal altered ecosystem states. We report a large shift in the biological communities of San Francisco Bay, first detected as increasing phytoplankton biomass and occurrences of new seasonal blooms that began in 1999. This phytoplankton increase is...
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...
Distinguishing native (Celastrus scandens L.) and invasive (C. orbiculatus Thunb.) bittersweet species using morphological characteristics
S. A. Leicht-Young, N.B. Pavlovic, R. Grundel, K.J. Frohnapple
2007, Journal of the Torrey Botanical Society (134) 441-450
Celastrus orbiculatus is an invasive liana in the Eastern United States. Its native congener, C. scandens, is less common and declining in the Northeast. The correct identification of these two species is often difficult because of their similar vegetative characteristics. Using morphological characteristics of both species growing naturally along a sand dune/forest...
Geology of the Yucca Mountain site area, southwestern Nevada
W. R. Keefer, J.W. Whitney, D.C. Buesch
2007, Memoir of the Geological Society of America (199) 53-103
Yucca Mountain in southwestern Nevada is a prominent, irregularly shaped upland formed by a thick apron of Miocene pyroclastic-flow and fallout tephra deposits, with minor lava flows, that was segmented by through-going, large-displacement normal faults into a series of north-trending, eastwardly tilted structural blocks. The principal volcanic-rock units are the...
Barrier island vulnerability to breaching: a case study on Dauphin Island, Alabama
Mark Hansen, Asbury H. Sallenger Jr.
2007, Conference Paper, Coastal Sediments '07 - Proceedings of 6th International Symposium on Coastal Engineering and Science of Coastal Sediment Processes
Breaching of barrier islands can adversely impact society by severing infrastructure, destroying private properties, and altering water quality in back bays and estuaries. This study provides a scheme that assesses the relative vulnerability of a barrier island to breach during storms. Dauphin Island, Alabama was selected for this study because...
Chesapeake Inundation Prediction System (CIPS): A regional prototype for a national problem
B. Stamey, W. Smith, K. Carey, D. Garbin, F. Klein, Hongfang Wang, J. Shen, W. Gong, J. Cho, D. Forrest, C. Friedrichs, W. Boicourt, M. Li, M. Koterba, D. King, J. Titlow, E. Smith, A. Siebers, J. Billet, J. Lee, Douglas R. Manning, G. Szatkowski, D. Wilson, P. Ahnert, J. Ostrowski
2007, Conference Paper, Oceans Conference Record (IEEE)
Recent Hurricanes Katrina and Isabel, among others, not only demonstrated their immense destructive power, but also revealed the obvious, crucial need for improved storm surge forecasting and information delivery to save lives and property in future storms. Current operational methods and the storm surge and inundation products do not adequately...
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...
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...
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...
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...
Pre-eruption recharge of the Bishop magma system
D.A. Wark, W. Hildreth, F.S. Spear, D.J. Cherniak, E.B. Watson
2007, Geology (35) 235-238
The 650 km3 rhyolitic Bishop Tuff (eastern California, USA), which is stratigraphically zoned with respect to temperatures of mineral equilibration, reflects a corresponding thermal gradient in the source magma chamber. Consistent with previous work, application of the new TitaniQ (Ti-in-quartz) thermometer to quartz phenocryst rims documents an ∼100 °C temperature increase...
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....
Resource availability, matrix quality, microclimate, and spatial pattern as predictors of patch use by the Karner blue butterfly
R. Grundel, N.B. Pavlovic
2007, Biological Conservation (135) 135-144
Determination of which aspects of habitat quality and habitat spatial arrangement best account for variation in a species’ distribution can guide management for organisms such as the Karner blue butterfly (Lycaeides melissa samuelis), a federally endangered subspecies inhabiting savannas of Midwest and Eastern United States. We examined the extent to...
