Mining-impacted sources of metal loading to an alpine stream based on a tracer-injection study, Clear Creek County, Colorado
David L. Fey, Laurie Wirt
2007, Reviews in Engineering Geology (17) 85-103
Base flow water in Leavenworth Creek, a tributary to South Clear Creek in Clear Creek County, Colorado, contains copper and zinc at levels toxic to aquatic life. The metals are predominantly derived from the historical Waldorf mine, and sources include an adit, a mine-waste dump, and mill-tailings deposits. Tracer-injection and...
Call for collaboration in WMO project for the assessment of the performance of flow measurement instruments and techniques
J.M. Fulford, P.J. Pilon, Z. Kopaliani, P.J. McCurry, C. Caponi
2007, Journal of Hydraulic Engineering (133) 1439-1440
[No abstract available]...
Topography and geomorphology of the Huygens landing site on Titan
Laurence A. Soderblom, Martin G. Tomasko, Brent A. Archinal, Tammy L. Becker, Michael W. Bushroe, Debbie Cook, Lyn R. Doose, Donna M. Galuszka, Trent M. Hare, Elpitha Howington-Kraus, Erich Karkoschka, Randolph L. Kirk, Jonathan I. Lunine, Elisabeth A. McFarlane, Bonnie L. Redding, Bashar Rizk, Mark R. Rosiek, Charles See, Peter H. Smith
2007, Planetary and Space Science (55) 2015-2024
The Descent Imager/Spectral Radiometer (DISR) aboard the Huygens Probe took several hundred visible-light images with its three cameras on approach to the surface of Titan. Several sets of stereo image pairs were collected during the descent. The digital terrain models constructed from those images show rugged topography, in places approaching...
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...
Ages, distributions, and origins of upland coastal dune sheets in Oregon, USA
C. D. Peterson, E. Stock, D.M. Price, R. Hart, F. Reckendorf, J.M. Erlandson, S. W. Hostetler
2007, Geomorphology (91) 80-102
A total of ten upland dune sheets, totaling 245??km in combined length, have been investigated for their origin(s) along the Oregon coast (500??km in length). The ages of dune emplacement range from 0.1 to 103??ka based on radiocarbon (36 samples) and luminescence (46 samples) dating techniques. The majority of the...
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...
Massive edifice failure at Aleutian arc volcanoes
Michelle L. Coombs, S.M. White, D.W. Scholl
2007, Earth and Planetary Science Letters (256) 403-418
Along the 450-km-long stretch of the Aleutian volcanic arc from Great Sitkin to Kiska Islands, edifice failure and submarine debris-avalanche deposition have occurred at seven of ten Quaternary volcanic centers. Reconnaissance geologic studies have identified subaerial evidence for large-scale prehistoric collapse events at five of the centers (Great Sitkin, Kanaga,...
Thermoregulation in larval aggregations of carrion-feeding blow flies (Diptera: Calliphoridae)
D. H. Slone, Susan V. Gruner
2007, Journal of Medical Entomology (44) 516-523
The growth and development of carrion-feeding calliphorid (Diptera Calliphoridae) larvae, or maggots, is of great interest to forensic sciences, especially for estimation of a postmortem interval (PMI). The development rate of calliphorid larvae is influenced by the temperature of their immediate environment. Heat generation in larval feeding aggregations (=maggot masses)...
Forest dynamics in Oregon landscapes: Evaluation and application of an individual-based model
R. T. Busing, A.M. Solomon, R.B. McKane, C.A. Burdick
2007, Ecological Applications (17) 1967-1981
The FORCLIM model of forest dynamics was tested against field survey data for its ability to simulate basal area and composition of old forests across broad climatic gradients in western Oregon, USA. The model was also tested for its ability to capture successional trends in ecoregions of the west Cascade...
Optimizing nest survival and female survival: Consequences of nest site selection for Canada Geese
David A. Miller, J.B. Grand, T.F. Fondell, R. Michael Anthony
2007, Condor (109) 769-780
We examined the relationship between attributes of nest sites used by Canada Geese (Branta canadensis) in the Copper River Delta, Alaska, and patterns in nest and female survival. We aimed to determine whether nest site attributes related to nest and female survival differed and whether nest site attributes related to...
Comparative lahar hazard mapping at Volcan Citlaltépetl, Mexico using SRTM, ASTER and DTED-1 digital topographic data
Bernard E. Hubbard, Michael F. Sheridan, Gerardo Carrasco-Nunez, Rodolfo Diaz-Castellon, Sergio R. Rodriguez
2007, Journal of Volcanology and Geothermal Research (160) 99-124
In this study, we evaluated and compared the utility of spaceborne SRTM and ASTER DEMs with baseline DTED-1 “bald-earth” topography for mapping lahar inundation hazards from volcan Citlaltépetl, Mexico, a volcano which has had a history of producing debris flows of various extents. In particular, we tested the utility...
Seasonal variations on the residence times and partitioning of short-lived radionuclides (234Th, 7Be and 210Pb) and depositional fluxes of 7Be and 210Pb in Tampa Bay, Florida
M. Baskaran, P.W. Swarzenski
2007, Marine Chemistry (104) 27-42
Historically, Tampa Bay has been impacted heavily by a wide range of anthropogenic perturbations that may include, agricultural-, shipping-, phosphate mining/distribution-related activities, as well as a burgeoning coastal population. Due to the presence of U-rich underlying sediments, elevated activities of U- and Th-series daughter products may be naturally released into...
Potential economic impact of introduction and spread of the red imported fire ant, Solenopsis invicta, in Hawaii
J.J. Gutrich, E. VanGelder, L. Loope
2007, Environmental Science and Policy (10) 685-696
Globally, many invasive alien species have caused extensive ecological and economic damage from either accidental or intentional introduction. The red imported fire ant, Solenopsis invicta, has created billions of dollars in costs annually, spreading as an invasive species across the southern United States. In 1998, the red imported fire ant...
Sap flow characteristics of neotropical mangroves in flooded and drained soils
Ken W. Krauss, P. Joy Young, Jim L. Chambers, Thomas W. Doyle, Robert R. Twilley
2007, Tree Physiology (27) 775-783
Effects of flooding on water transport in mangroves have previously been investigated in a few studies, most of which were conducted on seedlings in controlled settings. In this study, we used heat-dissipation sap probes to determine if sap flow (Js) attenuates with radial depth into the xylem of mature trees...
Plumbing the global carbon cycle: Integrating inland waters into the terrestrial carbon budget
J. J. Cole, Y.T. Prairie, N.F. Caraco, W. H. McDowell, L.J. Tranvik, Robert G. Striegl, C.M. Duarte, Pirkko Kortelainen, J. A. Downing, J.J. Middelburg, J. Melack
2007, Ecosystems (10) 171-184
Because freshwater covers such a small fraction of the Earth's surface area, inland freshwater ecosystems (particularly lakes, rivers, and reservoirs) have rarely been considered as potentially important quantitative components of the carbon cycle at either global or regional scales. By taking published estimates of gas exchange, sediment accumulation, and carbon...
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...
Identifying biotic integrity and water chemistry relations in nonwadeable rivers of Wisconsin: Toward the development of nutrient criteria
B.M. Weigel, Dale M. Robertson
2007, Environmental Management (40) 691-708
We sampled 41 sites on 34 nonwadeable rivers that represent the types of rivers in Wisconsin, and the kinds and intensities of nutrient and other anthropogenic stressors upon each river type. Sites covered much of United States Environmental Protection Agency national nutrient ecoregions VII-Mostly Glaciated Dairy Region, and VIII-Nutrient Poor,...
Drying temperature effects on fish dry mass measurements
B.F. Lantry, R. O'Gorman
2007, Journal of Great Lakes Research (33) 606-616
Analysis of tissue composition in fish often requires dry samples. Time needed to dry fish decreases as temperature is increased, but additional volatile material may be lost. Effects of 10??C temperature increases on percentage dry mass (%DM) were tested against 60??C controls for groups of lake trout Salvelinus namaycush, rainbow...
Geologic framework of the Mississippian Barnett Shale, Barnett-Paleozoic total petroleum system, Bend arch-Fort Worth Basin, Texas
R. M. Pollastro, D.M. Jarvie, R.J. Hill, C.W. Adams
2007, American Association of Petroleum Geologists Bulletin (91) 405-436
This article describes the primary geologic characteristics and criteria of the Barnett Shale and Barnett-Paleozoic total petroleum system (TPS) of the Fort Worth Basin used to define two geographic areas of the Barnett Shale for petroleum resource assessment. From these two areas, referred to as "assessment units," the U.S. Geological...
Dynamics of cover, UV-protective pigments, and quantum yield in biological soil crust communities of an undisturbed Mojave Desert shrubland
Jayne Belnap, Susan L. Phillips, Stanley D. Smith
2007, Flora (202) 674-686
Biological soil crusts are an integral part of dryland ecosystems. We monitored the cover of lichens and mosses, cyanobacterial biomass, concentrations of UV-protective pigments in both free-living and lichenized cyanobacteria, and quantum yield in the soil lichen species Collema in an undisturbed Mojave Desert shrubland. During our sampling time, the...
Attenuation of ground-motion spectral amplitudes in southeastern Australia
T.I. Allen, P.R. Cummins, T. Dhu, J.F. Schneider
2007, Bulletin of the Seismological Society of America (97) 1279-1292
A dataset comprising some 1200 weak- and strong-motion records from 84 earthquakes is compiled to develop a regional ground-motion model for southeastern Australia (SEA). Events were recorded from 1993 to 2004 and range in size from moment magnitude 2.0 ??? M ??? 4.7. The decay of vertical-component Fourier spectral amplitudes...
First documentation of tidal-channel sponge biostromes (upper Pleistocene, southeastern Florida)
K.J. Cunningham, J.K. Rigby, M.A. Wacker, H.A. Curran
2007, Geology (35) 475-478
Sponges are not a common principal component of Cenozoic reefs and are more typically dominant in deep-water and/or cold-water localities. Here we report the discovery of extensive upper Pleistocene shallow-marine, tropical sponge biostromes from the Mami Limestone of southeastern Florida built by a new ceractinomorph demosponge. These upright, barrel- to...
Oil and gas geochemistry and petroleum systems of the Fort Worth Basin
R.J. Hill, D.M. Jarvie, J. Zumberge, M. Henry, R. M. Pollastro
2007, American Association of Petroleum Geologists Bulletin (91) 445-473
Detailed biomarker and light hydrocarbon geochemistry confirm that the marine Mississippian Barnett Shale is the primary source rock for petroleum in the Fort Worth Basin, north-central Texas, although contributions from other sources are possible. Biomarker data indicate that the main oil-generating Barnett Shale facies is marine and was deposited under...
Amplitude loss of sonic waveform due to source coupling to the medium
Myung W. Lee, William F. Waite
2007, Geophysical Research Letters (34)
In contrast to hydrate-free sediments, sonic waveforms acquired in gas hydrate-bearing sediments indicate strong amplitude attenuation associated with a sonic velocity increase. The amplitude attenuation increase has been used to quantify pore-space hydrate content by attributing observed attenuation to the hydrate-bearing sediment's intrinsic attenuation. A second attenuation mechanism must be...
Keeping pace with Capitol Hill
C. Cooper
2007, Conference Paper, GSA Today
At the Capitol Hill, the legislative branch of the United States government, the work is always at pace. Working with Congress is a tough job yet, rewarding. The Congress worked hard together to serve the public interest but many big issues are one small part of what Congress does. However,...
