Feasibility of detecting near-surface feature with Rayleigh-wave diffraction
J. Xia, Jonathan E. Nyquist, Y. Xu, M.J.S. Roth, R. D. Miller
2007, Journal of Applied Geophysics (62) 244-253
Detection of near-surfaces features such as voids and faults is challenging due to the complexity of near-surface materials and the limited resolution of geophysical methods. Although multichannel, high-frequency, surface-wave techniques can provide reliable shear (S)-wave velocities in different geological settings, they are not suitable for detecting voids directly based on...
Hydrodynamics of coalbed methane reservoirs in the Black Warrior Basin: Key to understanding reservoir performance and environmental issues
J.C. Pashin
2007, Applied Geochemistry (22) 2257-2272
The Black Warrior Basin of the southeastern United States hosts one of the world's most prolific and long-lived coalbed methane plays, and the wealth of experience in this basin provides insight into the relationships among basin hydrology, production performance, and environmental issues. Along the southeast margin of the basin, meteoric...
A shifting mosaic of scholarly publishing, scientific delivery, and future impact changing the face of learned societies
David M. Leslie Jr.
2007, Journal of Mammalogy (88) 275-286
Nonprofit scientific societies hope that their activities advance their particular mission and impact their profession and, in the broadest sense, humanity in positive ways. The digital age has provided unprecedented mechanisms to enhance the delivery of science to the world. The marketplace of scientific publishing is a rapidly shifting mosaic...
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...
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...
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...
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;...
Forces on stationary particles in near-bed turbulent flows
M.W. Schmeeckle, J. M. Nelson, R.L. Shreve
2007, Journal of Geophysical Research F: Earth Surface (112)
In natural flows, bed sediment particles are entrained and moved by the fluctuating forces, such as lift and drag, exerted by the overlying flow on the particles. To develop a better understanding of these forces and the relation of the forces to the local flow, the downstream and vertical components...
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...
Dominant factors in controlling marine gas pools in South China
S. Xu, W.L. Watney
2007, Frontiers of Earth Science in China (1) 491-497
In marine strata from Sinian to Middle Triassic in South China, there develop four sets of regional and six sets of local source rocks, and ten sets of reservoir rocks. The occurrence of four main formation periods in association with five main reconstruction periods, results in a secondary origin for...
Coastal-change impacts during hurricane katrina: an overview
Asbury Sallenger, C. Wayne Wright, Jeff Lillycrop
2007, Conference Paper, Coastal Sediments '07 - Proceedings of 6th International Symposium on Coastal Engineering and Science of Coastal Sediment Processes
As part of an ongoing cooperative effort between USGS, NASA and USACE, the barrier islands within the right-front quadrant of Hurricane Katrina were surveyed with airborne lidar both before and after landfall. Dauphin Island, AL was located the farthest from landfall and wave runup intermittently overtopped its central and western...
Glacier changes in southeast Alaska and northwest British Columbia and contribution to sea level rise
C.F. Larsen, R.J. Motyka, A.A. Arendt, K.A. Echelmeyer, P.E. Geissler
2007, Journal of Geophysical Research F: Earth Surface (112)
The digital elevation model (DEM) from the 2000 Shuttle Radar Topography Mission (SRTM) was differenced from a composite DEM based on air photos dating from 1948 to 1987 to detennine glacier volume changes in southeast Alaska and adjoining Canada. SRTM accuracy was assessed at ??5 in through comparison with airborne...
Linking occurrence and fitness to persistence: Habitat-based approach for endangered Greater Sage-Grouse
Cameron L. Aldridge, Mark S. Boyce
2007, Ecological Applications (17) 508-526
Detailed empirical models predicting both species occurrence and fitness across a landscape are necessary to understand processes related to population persistence. Failure to consider both occurrence and fitness may result in incorrect assessments of habitat importance leading to inappropriate management strategies. We took a two-stage approach to identifying critical nesting...
Unconventional shale-gas systems: The Mississippian Barnett Shale of north-central Texas as one model for thermogenic shale-gas assessment
D.M. Jarvie, R.J. Hill, T.E. Ruble, R. M. Pollastro
2007, American Association of Petroleum Geologists Bulletin (91) 475-499
Shale-gas resource plays can be distinguished by gas type and system characteristics. The Newark East gas field, located in the Fort Worth Basin, Texas, is defined by thermogenic gas production from low-porosity and low-permeability Barnett Shale. The Barnett Shale gas system, a self-contained source-reservoir system, has generated large amounts of...
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....
Thermal criteria for early life stage development of the winged mapleleaf mussel (Quadrilla fragosa)
M.T. Steingraeber, M.R. Bartsch, J.E. Kalas, T.J. Newton
2007, American Midland Naturalist (157) 297-311
The winged mapleleaf mussel [Quadrula fragosa (Conrad)] is a Federal endangered species. Controlled propagation to aid in recovering this species has been delayed because host fishes for its parasitic glochidia (larvae) are unknown. This study identified blue catfish [Ictaluris furcatus (Lesueur)] and confirmed channel catfish [Ictaluris punctatus (Rafinesque)] as suitable...
Effect of bedrock permeability on subsurface stormflow and the water balance of a trenched hillslope at the Panola Mountain Research Watershed, Georgia, USA
Meerveld H. J. Tromp-van H. J., N.E. Peters, Jeffery J. McDonnell
2007, Hydrological Processes (21) 750-769
The effect of bedrock permeability on subsurface stormflow initiation and the hillslope water balance is poorly understood. Previous hillslope hydrological studies at the Panola Mountain Research Watershed (PMRW), Georgia, USA, have assumed that the bedrock underlying the trenched hillslope is effectively impermeable. This paper presents a series of sprinkling experiments...
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...
Simple predictions of maximum transport rate in unsaturated soil and rock
John R. Nimmo
2007, Water Resources Research (43)
In contrast with the extreme variability expected for water and contaminant fluxes in the unsaturated zone, evidence from 64 field tests of preferential flow indicates that the maximum transport speed Vmax, adjusted for episodicity of infiltration, deviates little from a geometric mean of 13 m/d. A model based on constant‐speed travel...
Evidence for prosauropod dinosaur gastroliths in the Bull Run Formation (Upper Triassic, Norian) of Virginia
Robert E. Weems, Michelle J. Culp, Oliver Wings
2007, Ichnos: An International Journal for Plant and Animal Traces (14) 271-295
Definitive criteria for distinguishing gastroliths from sedimentary clasts are lacking for many depositional settings, and many reported occurrences of gastroliths either cannot be verified or have been refuted. We discuss four occurrences of gastrolith-like stones (category 6 exoliths) not found within skeletal remains from the Upper Triassic Bull Run Formation...
Using biodynamic models to reconcile differences between laboratory toxicity tests and field biomonitoring with aquatic insects
D.B. Buchwalter, Daniel J. Cain, W.H. Clements, S. N. Luoma
2007, Environmental Science & Technology (41) 4821-4828
Aquatic insects often dominate lotic ecosystems, yet these organisms are under-represented in trace metal toxicity databases. Furthermore, toxicity data for aquatic insects do not appear to reflect their actual sensitivities to metals in nature, because the concentrations required to elicit toxicity...
Early vegetation development on an exposed reservoir: Implications for dam removal
G.T. Auble, P.B. Shafroth, M. L. Scott, J. E. Roelle
2007, Environmental Management (39) 806-818
The 4-year drawdown of Horsetooth Reservoir, Colorado, for dam maintenance, provides a case study analog of vegetation response on sediment that might be exposed from removal of a tall dam. Early vegetation recovery on the exposed reservoir bottom was a combination of (1) vegetation colonization on bare, moist substrates typical...
Utility of R0 as a predictor of disease invasion in structured populations
Paul C. Cross, Philip L. Johnson, James O. Lloyd-Smith, Wayne M. Getz
2007, Journal of the Royal Society Interface (4) 315-324
Early theoretical work on disease invasion typically assumed large and well-mixed host populations. Many human and wildlife systems, however, have small groups with limited movement among groups. In these situations, the basic reproductive number, R0, is likely to be a poor predictor of a disease pandemic because it typically does not...
Modeling the influence of river discharge on salt intrusion and residual circulation in Danshuei River estuary, Taiwan
W.-C. Liu, W.-B. Chen, R. T. Cheng, M.-H. Hsu, A.Y. Kuo
2007, Continental Shelf Research (27) 900-921
A 3-D, time-dependent, baroclinic, hydrodynamic and salinity model was implemented and applied to the Danshuei River estuarine system and the adjacent coastal sea in Taiwan. The model forcing functions consist of tidal elevations along the open boundaries and freshwater inflows from the main stream and major tributaries in the Danshuei...
Species-area curves indicate the importance of habitats' contributions to regional biodiversity
G.W. Chong, T.J. Stohlgren
2007, Ecological Indicators (7) 387-395
We examined species-area curves, species composition and similarity (Jaccard's coefficients), and species richness in 17 vegetation types to develop a composite index of a vegetation type's contribution to regional species richness. We collected data from 1 to 1000 m2 scales in 147 nested plots in Rocky Mountain National Park, Colorado,...
