In situ time-series measurements of subseafloor sediment properties
R. A. Wheatcroft, A.W. Stevens, R.V. Johnson
2007, IEEE Journal of Oceanic Engineering (32) 862-871
The capabilities and diversity of subsurface sediment sensors lags significantly from what is available for the water column, thereby limiting progress in understanding time-dependent seabed exchange and high-frequency acoustics. To help redress this imbalance, a new instrument, the autonomous sediment profiler (ASP), is described herein....
Cleats and their relation to geologic lineaments and coalbed methane potential in Pennsylvanian coals in Indiana
W. Solano-Acosta, Maria Mastalerz, A. Schimmelmann
2007, International Journal of Coal Geology (72) 187-208
Cleats and fractures in Pennsylvanian coals in southwestern Indiana were described, statistically analyzed, and subsequently interpreted in terms of their origin, relation to geologic lineaments, and significance for coal permeability and coalbed gas generation and storage. These cleats can be interpreted as the result of superimposed endogenic and exogenic processes....
Evaluation of a small beach nourishment project to enhance habitat suitability for horseshoe crabs
N.L. Jackson, D. R. Smith, R. Tiyarattanachai, K.F. Nordstrom
2007, Geomorphology (89) 172-185
This field study evaluates the effect of nourishing an estuarine beach with gravel to enhance spawning rates by horseshoe crabs. A total of 564??m3 of coarse sand and gravel were emplaced in two 90??m-long treatment segments at Bowers Beach, Delaware, USA from 9 to 11 April 2002. Field data were...
Velafrons coahuilensis, a new labeosaurine haddrosaurid (Dinosauria: Ornithopoda) from the Late Campanian Cerro del Pueblo formation, Coahuila, Mexico
Terry A. Gates, Scott D. Sampson, Carlos R. Delgado de Jesus, Lindsay E. Zanno, David Eberth, Rene Hernandez-Rivera, Martha C. Aguillon-Martinez, James I. Kirkland
2007, Journal of Vertebrate Paleontology (27) 917-930
A new lambeosaurine hadrosaurid, Velafrons coahuilensis, is described as the first lambeosaurine from the Cerro del Pueblo Formation of Coahuila, Mexico, and the first lambeosaurine genus to be named from North America in more than 70 years. Although the holotype specimen is a juvenile individual—as evidenced by its incomplete crest development...
Infection by a black spot-causing species of Uvulifer and associated opercular alterations in fishes from a high-desert stream in Wyoming
M.C. Quist, M.R. Bower, W.A. Hubert
2007, Diseases of Aquatic Organisms (78) 129-136
Black spot is a common disease syndrome of freshwater fishes. This study provides information on the rank of density of the black spot agent and opercular bone alterations associated with at least one digenean, Uvulifer sp., infecting native and non-native catostomids and cyprinids of the Upper Colorado River Basin. We...
Bed forms created by simulated waves and currents in a large flume
Jessica R. Lacy, David M. Rubin, Hiroshi Ikeda, Kuniyasu Mokudai, Daniel M. Hanes
2007, Journal of Geophysical Research C: Oceans (112)
The morphology and evolution of bed forms created by combinations of waves and currents were investigated using an oscillating plate in a 4-m-wide flume. Current speed ranged from 0 to 30 cm/s, maximum oscillatory velocity ranged from 20 to 48 cm/s, oscillation period was 8 s (except for one run...
Estimating fishing mortality, natural mortality, and selectivity using recoveries from tagging young fish
H. Jiang, C. Brownie, J.E. Hightower, K. H. Pollock
2007, North American Journal of Fisheries Management (27) 773-781
Current methods for estimation of age- and year-specific instantaneous mortality rates based on multiyear, multiple-age tagging studies assume that it is feasible to tag fish in a wide range of ages. For some species, however, only the youngest one or two age-classes are readily available for tagging. Given the practical...
Early Tertiary transtension-related deformation and magmatism along the Tintina fault system, Alaska
A.B. Till, S. M. Roeske, D. C. Bradley, R. Friedman, P.W. Layer
2007, Special Paper of the Geological Society of America (434) 233-264
Transtensional deformation was concentrated in a zone adjacent to the Tintina strike-slip fault system in Alaska during the early Tertiary. The deformation occurred along the Victoria Creek fault, the trace of the Tintina system that connects it with the Kaltag fault; together the Tintina and Kaltag fault systems girdle Alaska...
Seismic hazard and risk assessment in the intraplate environment: The New Madrid seismic zone of the central United States
Z. Wang
2007, Special Paper of the Geological Society of America 363-374
Although the causes of large intraplate earthquakes are still not fully understood, they pose certain hazard and risk to societies. Estimating hazard and risk in these regions is difficult because of lack of earthquake records. The New Madrid seismic zone is one such region where large and rare intraplate earthquakes...
Nesting and foraging behavior of red-winged blackbirds in stormwater wetlands
D. W. Sparling, J. Eisemann, W. Kuenzel
2007, Urban Ecosystems (10) 1-15
Stormwater wetlands are a common part of urban and suburban landscapes. These constructed wetlands provide first-order treatment of effluent from roads, parking lots, lawns and other surfaces. They also provide habitat for wetland-associated birds. Thus, there is a concern that birds may be attracted to potentially toxic habitats. This study...
Diversity of terrestrial avifauna in response to distance from the shoreline of the Salton Sea
M.B. Mendelsohn, W.I. Boarman, Robert N. Fisher, S.A. Hathaway
2007, Journal of Arid Environments (68) 574-587
Large aquatic bodies influence surrounding terrestrial ecosystems by providing water and nutrients. In arid landscapes, the increased primary productivity that results may greatly enhance vertebrate biodiversity. The Salton Sea, a large saline lake in the Colorado Desert of southern California, provides nutrients...
Effect of relative volume on radio transmitter expulsion in subadult common carp
C.R. Penne, N.L. Ahrens, R.C. Summerfelt, C.L. Pierce
2007, North American Journal of Fisheries Management (27) 986-991
Expulsion of surgically implanted radio transmitters is a problem in some fish telemetry studies. We conducted a 109-d experiment to test the hypothesis that variation in relative volume of transmitters surgically implanted in subadult common carp Cyprinus carpio would affect transmitter expulsion. We also necropsied fish at the end of...
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...
Evidence for a physical linkage between galactic cosmic rays and regional climate time series
C. A. Perry
2007, Advances in Space Research (40) 353-364
The effects of solar variability on regional climate time series were examined using a sequence of physical connections between total solar irradiance (TSI) modulated by galactic cosmic rays (GCRs), and ocean and atmospheric patterns that affect precipitation and streamflow. The solar energy reaching the Earth's surface and its oceans is...
Habitat classification modeling with incomplete data: Pushing the habitat envelope
P.L. Zarnetske, T.C. Edwards Jr., Gretchen G. Moisen
2007, Ecological Applications (17) 1714-1726
Habitat classification models (HCMs) are invaluable tools for species conservation, land-use planning, reserve design, and metapopulation assessments, particularly at broad spatial scales. However, species occurrence data are often lacking and typically limited to presence points at broad scales. This lack of absence data precludes the use of many statistical techniques...
Spatial and temporal variations in silver contamination and toxicity in San Francisco Bay
A.R. Flegal, Cynthia L. Brown, S. Squire, J.R.M. Ross, G.M. Scelfo, S. Hibdon
2007, Environmental Research (105) 34-52
Although San Francisco Bay has a "Golden Gate", it may be argued that it is the "Silver Estuary". For at one time the Bay was reported to have the highest levels of silver in its sediments and biota, along with the only accurately measured values of silver in solution, of...
Diverse dinosaur-dominated ichnofaunas from the Potomac Group (Lower Cretaceous) Maryland
Ray Stanford, Martin G. Lockley, Robert E. Weems
2007, Ichnos: An International Journal for Plant and Animal Traces (14) 155-173
Until recently fossil footprints were virtually unknown from the Cretaceous of the eastern United States. The discovery of about 300 footprints in iron-rich siliciclastic facies of the Patuxent Formation (Potomac Group) of Aptian age is undoubtedly one of the most significant Early Cretaceous track discoveries since the Paluxy track discoveries...
Nitrous oxide fluxes from cultivated areas and rangeland: U.S. High Plains
Edwin P. Weeks, Peter B. McMahon
2007, Vadose Zone Journal (6) 496-510
Concentration profiles of N2O, a greenhouse gas, and the conservative trace gases SF6 and the chlorofluorocarbons CFC-11, CFC-12, CFC-113, and were measured periodically through thick vadose zones at nine sites in the U.S. High Plains. The CFC and SF6 measurements were used to calibrate a one-dimensional gas diffusion model, using...
Multiple-method estimation of recharge rates at diverse locations in the North Carolina Coastal Plain, USA
A. L. Coes, T.B. Spruill, M.J. Thomasson
2007, Hydrogeology Journal (15) 773-788
Recharge rates determined at diverse study sites in a shallow, unconfined aquifer differed from one another depending on the analytical method used and on each method's applicability and limitations. Total recharge was quantified with saturated-zone methods using water-table fluctuations at seven sites in North Carolina, USA and using groundwater-age dating...
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...
Cryovolcanic features on Titan's surface as revealed by the Cassini Titan Radar Mapper
Rosaly Lopes, K. L. Mitchell, Ellen R. Stofan, Jonathan I. Lunine, Ralf D. Lorenz, F. Paganelli, Randolph L. Kirk, C. A. Wood, Stephen D. Wall, L.E. Robshaw, A.D. Fortes, Catherine D. Neish, Jani Radebaugh, E. Reffet, S.J. Ostro, Charles Elachi, M.D. Allison, Y. Anderson, R. Boehmer, G. Boubin, Philip S. Callahan, P. Encrenaz, E. Flamini, G. Francescetti, Y. Gim, G. Hamilton, S. Hensley, Michael A. Janssen, W.T.K. Johnson, K. Kelleher, D.O. Muhleman, G. Ori, R. Orosei, G. Picardi, F. Posa, L.E. Roth, R. Seu, S. Shaffer, Laurence A. Soderblom, B. Stiles, S. Vetrella, R.D. West, L. Wye, H. A. Zebker
2007, Icarus (186) 395-412
The Cassini Titan Radar Mapper obtained Synthetic Aperture Radar images of Titan's surface during four fly-bys during the mission's first year. These images show that Titan's surface is very complex geologically, showing evidence of major planetary geologic processes, including cryovolcanism. This paper discusses the variety of cryovolcanic features identified from...
Winter behavior and ecology of the Alder Flycatcher (Empidonax alnorum) in Peru
M.S. Foster
2007, Ornitologia Neotropical (18) 171-186
The winter ecology and behavior of Alder Flycatchers (Empidonax alnorum) were studied along the Manu, a white-water meander river in Manu National Park, Madre de Dios, Peru?? during October and November, 1993 to 1997. The birds occupied territories in primary-succession habitats on growing point bars. They were most common in...
Sexual selection drives speciation in an Amazonian frog
K.E. Boul, W.C. Funk, C.R. Darst, D.C. Cannatella, M.J. Ryan
2007, Proceedings of the Royal Society B: Biological Sciences (274) 399-406
One proposed mechanism of speciation is divergent sexual selection, whereby divergence in female preferences and male signals results in behavioural isolation. Despite the appeal of this hypothesis, evidence for it remains inconclusive. Here, we present several lines of evidence that sexual selection is driving behavioural isolation and speciation among populations...
Using drill cutting separates to estimate the strength of narrow shear zones at SAFOD
C. Morrow, J. Solum, S. Tembe, D. Lockner, T.-F. Wong
2007, Geophysical Research Letters (34)
[1] A technique is presented for estimating frictional strength of narrow shear zones based on hand selection of drillhole cuttings separates. Tests were conducted on cuttings from the SAFOD scientific drillhole near Parkfield, California. Since cuttings are mixed with adjacent material as they travel up the...
Quasi-horizontal circulation cells in 3D seawater intrusion
E. Abarca, J. Carrera, X. Sanchez-Vila, Clifford I. Voss
2007, Journal of Hydrology (339) 118-129
The seawater intrusion process is characterized by the difference in freshwater and seawater density that causes freshwater to float on seawater. Many confined aquifers have a large horizontal extension with respect to thickness. In these cases, while buoyancy acts in the vertical direction, flow is confined between the upper and...
