The Pennsylvanian-early permian bird spring carbonate shelf, Southeastern California: Fusulinid biostratigraphy, paleogeographic evolution, and tectonic implications
C.H. Stevens, P. Stone
2007, Special Paper of the Geological Society of America (429) 1-82
The Bird Spring Shelf in southeastern California, along with coeval turbidite basins to the west, records a complex history of late Paleozoic sedimentation, sea-level changes, and deformation along the western North American continental margin. We herein establish detailed correlations between deposits of the shelf and the flanking basins, which we...
Detrital zircon geochronology of some neoproterozoic to triassic rocks in interior Alaska
D. C. Bradley, W.C. McClelland, J. L. Wooden, A.B. Till, S. M. Roeske, Marti L. Miller, Susan M. Karl, J.G. Abbott
2007, Special Paper of the Geological Society of America 155-189
No abstract available. ...
The geophysical character of southern Alaska - Implications for crustal evolution
R. W. Saltus, T. L. Hudson, Frederic H. Wilson
2007, Special Paper of the Geological Society of America (431) 1-20
The southern Alaska continental margin has undergone a long and complicated history of plate convergence, subduction, accretion, and margin-parallel displacements. The crustal character of this continental margin is discernible through combined analysis of aeromagnetic and gravity data with key constraints from previous seismic interpretation. Regional magnetic data are particularly useful...
Salt tectonics and shallow subseafloor fluid convection: Models of coupled fluid-heat-salt transport
A. Wilson, C. Ruppel
2007, Geofluids (7) 377-386
Thermohaline convection associated with salt domes has the potential to drive significant fluid flow and mass and heat transport in continental margins, but previous studies of fluid flow associated with salt structures have focused on continental settings or deep flow systems of importance to petroleum exploration. Motivated by recent geophysical...
Subspecific variation in the widespread burl-forming Arctostaphylos glandulosa
Jon E. Keeley, Michael C. Vasey, V. Thomas Parker
2007, Madroño (54) 42-62
The genus Arctostaphylos consists mostly of chaparral shrubs known by the common name manzanita, and one of the widest ranging of these is A. glandulosa Eastw., distributed from Baja California to Oregon. Particularly in the southern half of its range it exhibits complex patterns of morphological variation that have long presented taxonomic challenges. Phenetic...
Thamnophis hammondii foraging behavior
Edward L. Ervin, Robert N. Fisher
2007, Herpetological Review (38) 345-346
Thamnophis hammondii is considered one of the most aquatic of the gartersnakes and is closely associated with creeks and impoundments (Fitch 1940. Univ. California Publ. Zool. 44:1–150) with a diet consisting largely of both the larvae and transformed stages of amphibians (Spea, Bufo, Rana, Pseudacris) and small fish (Oncorhynchus, Gasterosteus,...
DOM in recharge waters of the Santa Ana River Basin
J.A. Leenheer, G. R. Aiken, G. Woodside, K. O’Connor-Patel
2007, Journal - American Water Works Association (99) 118-131
Assessment of the composition, reactivity, and potential health effects of dissolved organic matter (DOM) is an important issue in the regulation and operation of groundwater recharge projects. The composition of DOM in various natural surface waters and reclaimed waters used to recharge the alluvial aquifers of the lower Santa Ana...
Dating young geomorphic surfaces using age of colonizing Douglas fir in southwestern Washington and northwestern Oregon, USA
T.C. Pierson
2007, Earth Surface Processes and Landforms (32) 811-831
Dating of dynamic, young (<500 years) geomorphic landforms, particularly volcanofluvial features, requires higher precision than is possible with radiocarbon dating. Minimum ages of recently created landforms have long been obtained from tree-ring ages of the oldest trees growing on new surfaces. But to estimate the year of landform creation requires...
A new deepwater species of the snake eel genus Ophichthus (Anguilliformes: Ophichthidae) from North Carolina
J.E. McCosker, Steve W. Ross
2007, Copeia 783-787
Ophichthus brevirostris, a new species of snake eel, subfamily Ophichthinae, is described from a specimen trawled in deep water (406-440 m) off North Carolina. It is distinguished from its congeners by the following combination of characters: large orbit; filamentous pectoral fin; two preopercular pores; short snout; minute dentition; body coloration;...
Egg flotation estimates nest age for Pacific and Red-throated Loons
Daniel Rizzolo, Joel A. Schmutz
2007, Waterbirds (30) 207-213
We used Pacific Loon (Gavia pacifica) and Red-throated Loon (G. stellata) nests with known ages to gauge the efficacy of egg flotation for determining nest age in coastal Alaska. Egg flotation accurately estimated nest age for both species; the mean ± 1SD difference between known age and age determined with egg...
Understanding shallow gas occurrences in the Gulf of Lions
Ana Garcia-Garcia, Tommaso Tesi, Daniel L. Orange, T. Lorenson, Stefano Miserocchi, L. Langone, I. Herbert, J. Dougherty
2007, Geo-Marine Letters (27) 143-154
New coring data have been acquired along the western Gulf of Lions showing anomalous concentrations of methane (up to 95,700 ppm) off the Rhône prodelta and the head of the southern canyons Lacaze-Duthiers and Cap de Creus. Sediment cores were acquired with box and kasten cores during...
Flux and age of dissolved organic carbon exported to the Arctic Ocean: A carbon isotopic study of the five largest arctic rivers
P.A. Raymond, J.W. McClelland, R.M. Holmes, A.V. Zhulidov, K. Mull, B. J. Peterson, Robert G. Striegl, G. R. Aiken, T.Y. Gurtovaya
2007, Global Biogeochemical Cycles (21)
The export and Δ14C-age of dissolved organic carbon (DOC) was determined for the Yenisey, Lena, Ob', Mackenzie, and Yukon rivers for 2004–2005. Concentrations of DOC elevate significantly with increasing discharge in these rivers, causing approximately 60% of the annual export to occur during a 2-month period following spring ice breakup....
Shoreline change as a proxy for subaerial beach volume change
Amy S. Farris, Jeffrey H. List
2007, Journal of Coastal Research (23) 740-748
It is difficult and expensive to calculate changes in sediment volume for large sections of sandy beaches. Shoreline change could be a useful proxy for volume change because it can be collected quickly and relatively easily over long distances. In this paper, we summarize several studies that find a high...
230Th-U dating of surficial deposits using the ion microprobe (SHRIMP-RG): A microstratigraphic perspective
K. Maher, J. L. Wooden, J.B. Paces, D. M. Miller
2007, Quaternary International (166) 15-28
We used the sensitive high-resolution ion microprobe reverse-geometry (SHRIMP-RG) to date pedogenic opal using the 230Th–U system. Due to the high-spatial resolution of an ion microprobe (typically 30 μm), regions of pure opal within a sample can be targeted and detrital material can be avoided. In addition, because the technique is non-destructive,...
Monitoring volcano threats from space
Kenneth A. Duda, Rick L. Wessels, Michael Ramsey, Jonathan Dehn
2007, Earthzine (December)
Volcanoes can have extremely wide ranging effects. Even a single eruption can cause disastrous climate changes at great distance from the source. Thus, it is important to have a system to monitor even the most remote volcanoes. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on the Terra spacecraft...
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...
Increase in nuisance blooms and geographic expansion of the freshwater diatom Didymosphenia geminata
S. A. Spaulding, E. Elwell
2007, Open-File Report 2007-1425
The diatom Didymosphenia geminata (Lyngbye) Schmidt is emerging as an organism with an extraordinary capacity to impact stream ecosystems on a global scale. In recent years, streams in New Zealand, North America, Europe, and Asia have been colonized by unprecedented masses of “didymo” and its extracellular stalks (fig. 1). This...
Topography-based analysis of Hurricane Katrina inundation of New Orleans
Dean Gesch
2007, Circular 1306-3G
The ready availability of high-resolution, high-accuracy elevation data proved valuable for development of topographybased products to determine rough estimates of the inundation of New Orleans, La., from Hurricane Katrina. Because of its high level of spatial detail and vertical accuracy of elevation measurements, light detection and ranging (lidar) remote sensing...
USGS Rocky Mountain Geographic Science Center’s 2005 hurricane response and recovery activities
Jill J. Cress, Susan E. Goplen, Jeff L. Sloan, Jennifer L. Stefanacci, Stanley R. Wilds
2007, Circular 1306-4A
Sophisticated monitoring systems and analysis products were key components to emergency response and Federal recovery activities during the 2005 hurricane season. The U.S. Geological Survey's (USGS) Rocky Mountain Geographic Science Center worked with a number of Federal agencies to provide these types of near real-time geospatial monitoring systems and analysis...
Data access and dissemination for emergency response and long-term recovery efforts related to Hurricanes Katrina and Rita
Scott Wilson, Chris Cretini
2007, Circular 1306-4B
The U.S. Geological Survey's (USGS) National Wetlands Research Center (NWRC) responded to Hurricanes Katrina and Rita by providing geospatial support to Federal, State, and local partners. The NWRC used its data and information management systems to deliver aerial photography and maps to emergency responders in a time of critical need....
Research on the impacts of past and future hurricanes on the endangered Florida manatee
Catherine A. Langtimm, M. Dennis Krohn, Bradley Stith, James P. Reid, C.A. Beck, Susan M. Butler
2007, Circular 1306-6J
U.S. Geological Survey (USGS) research on Florida manatees (Trichechus manatus latirostris) from 1982 through 1998 identified lower apparent survival rates for adult manatees during years when Hurricane Elena (1985), the March "Storm of the Century"(1993), and Hurricane Opal (1995) hit the northern coast of the Gulf of Mexico. Although our...
Characteristics of vesicomyid clams and their environment at the Blake Ridge cold seep, South Carolina, USA
Taylor P. Heyl, William P. Gilhooly III, Randolph M. Chambers, George W. Gilchrist, Stephen A. Macko, Carolyn D. Ruppel, Cindy L. Van Dover
2007, Marine Ecology Progress Series (339) 169-184
Spatial distributions and patchiness of dominant megafaunal invertebrates in deep-sea seep environments may indicate heterogeneities in the flux of reduced chemical compounds. At the Blake Ridge seep off South Carolina, USA, the invertebrate assemblage includes dense populations of live vesicomyid clams (an undescribed species) as well as extensive clam shell...
Population density, biomass, and age-class structure of the invasive clam Corbicula fluminea in rivers of the lower San Joaquin River watershed, California
Larry R. Brown, Janet K. Thompson, K. Higgins, Lisa V. Lucas
2007, Western North American Naturalist (67) 572-586
Corbicula fluminea is well known as an invasive filter-feeding freshwater bivalve with a variety of effects on ecosystem processes. However, C. fluminea has been relatively unstudied in the rivers of the western United States. In June 2003, we sampled C. fluminea at 16 sites in the San Joaquin River watershed of California, which was invaded...
Consistency of L4 TM absolute calibration with respect to the L5 TM sensor based on near-simultaneous image acquisition
G. Chander, D. L. Helder, R. Malla, E. Micijevic, C. J. Mettler
2007, Conference Paper, Proceedings of SPIE - The International Society for Optical Engineering
The Landsat archive provides more than 35 years of uninterrupted multispectral remotely sensed data of Earth observations. Since 1972, Landsat missions have carried different types of sensors, from the Return Beam Vidicon (RBV) camera to the Enhanced Thematic Mapper Plus (ETM+). However, the Thematic Mapper (TM) sensors on Landsat 4...
Climatic fluctuations and forecasting of streamflow in the lower Colorado River Basin
B. E. Thomas
2007, Journal of the American Water Resources Association (43) 1550-1569
Water-resource managers need to forecast streamflow in the Lower Colorado River Basin to plan for water-resource projects and to operate reservoirs for water supply. Statistical forecasts of streamflow based on historical records of streamflow can be useful, but statistical assumptions, such as stationarity of flows, need to be evaluated. This...
