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Page 746, results 18626 - 18650

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Publication Extents

Not all publications have extents, not all extents are completely accurate
Morphologic dating of fault scarps using airborne laser swath mapping (ALSM) data
G.E. Hilley, S. Delong, C. Prentice, K. Blisniuk, J.R. Arrowsmith Jr.
2010, Geophysical Research Letters (37)
Models of fault scarp morphology have been previously used to infer the relative age of different fault scarps in a fault zone using labor-intensive ground surveying. We present a method for automatically extracting scarp morphologic ages within high-resolution digital topography. Scarp degradation is modeled as a diffusive mass transport process...
Effects of nourishment on the form and function of an estuarine beach
N.L. Jackson, K.F. Nordstrom, S. Saini, D. R. Smith
2010, Ecological Engineering (36) 1709-1718
Beach nourishment programs in estuaries can enhance shore protection, but they decrease habitat suitability by creating higher berms and wider backshores than would occur under natural conditions. Use of sediment sources from outside the area can result in sedimentary characteristics that differ from native sediments on the surface and at...
Estimating length of avian incubation and nestling stages in afrotropical forest birds from interval-censored nest records
T.R. Stanley, W.D. Newmark
2010, The Auk (127) 79-85
In the East Usambara Mountains in northeast Tanzania, research on the effects of forest fragmentation and disturbance on nest survival in understory birds resulted in the accumulation of 1,002 nest records between 2003 and 2008 for 8 poorly studied species. Because information on the length of the incubation and nestling...
Using ecological function to develop recovery criteria for depleted species: Sea otters and kelp forests in the Aleutian archipelago
James A. Estes, M. Tim Tinker, James L. Bodkin
2010, Conservation Biology (24) 852-860
Recovery criteria for depleted species or populations normally are based on demographic measures, the goal being to maintain enough individuals over a sufficiently large area to assure a socially tolerable risk of future extinction. Such demographically based recovery criteria may be insufficient to restore the functional roles of strongly interacting...
Milankovitch-scale correlations between deeply buried microbial populations and biogenic ooze lithology
I.W. Aiello, B.A. Bekins
2010, Geology (38) 79-82
The recent discoveries of large, active populations of microbes in the subseafloor of the world's oceans supports the impact of the deep biosphere biota on global biogeochemical cycles and raises important questions concerning the functioning of these extreme environments for life. These investigations demonstrated that subseafloor microbes are unevenly distributed...
Decadal-timescale estuarine geomorphic change under future scenarios of climate and sediment supply
N. K. Ganju, D. H. Schoellhamer
2010, Estuaries and Coasts (33) 15-29
Future estuarine geomorphic change, in response to climate change, sea-level rise, and watershed sediment supply, may govern ecological function, navigation, and water quality. We estimated geomorphic changes in Suisun Bay, CA, under four scenarios using a tidal-timescale hydrodynamic/sediment transport model. Computational expense and data needs were reduced using the morphological...
Landscape effects on diets of two canids in Northwestern Texas: A multinomial modeling approach
P.R. Lemons, J.S. Sedinger, M.P. Herzog, P. S. Gipson, R.L. Gilliland
2010, Journal of Mammalogy (91) 66-78
Analyses of feces, stomach contents, and regurgitated pellets are common techniques for assessing diets of vertebrates and typically contain more than 1 food item per sampling unit. When analyzed, these individual food items have traditionally been treated as independent, which represents pseudoreplication. When food types are recorded as present or...
Calibration and use of continuous heat-type automated seepage meters for submarine groundwater discharge measurements
B.M. Mwashote, W. C. Burnett, J. Chanton, I.R. Santos, N. Dimova, P.W. Swarzenski
2010, Estuarine, Coastal and Shelf Science (87) 1-10
Submarine groundwater discharge (SGD) assessments were conducted both in the laboratory and at a field site in the northeastern Gulf of Mexico, using a continuous heat-type automated seepage meter (seepmeter). The functioning of the seepmeter is based on measurements of a temperature gradient in the water between downstream and upstream...
Extension in Mona Passage, Northeast Caribbean
J.D. Chaytor, Uri S. ten Brink
2010, Tectonophysics (493) 74-92
As shown by the recent Mw 7.0 Haiti earthquake, intra-arc deformation, which accompanies the subduction process, can present seismic and tsunami hazards to nearby islands. Spatially-limited diffuse tectonic deformation within the Northeast Caribbean Plate Boundary Zone likely led to the development of the submerged Mona Passage between Puerto Rico and...
Event-driven sediment flux in Hueneme and Mugu submarine canyons, southern California
J. P. Xu, P.W. Swarzenski, M. Noble, A.-C. Li
2010, Marine Geology (269) 74-88
Vertical sediment fluxes and their dominant controlling processes in Hueneme and Mugu submarine canyons off south-central California were assessed using data from sediment traps and current meters on two moorings that were deployed for 6 months during the winter of 2007. The maxima of total particulate flux, which reached as...
Standard-target calibration of an acoustic backscatter system
Kenneth G. Foote, Marinna A. Martini
2010, Conference Paper, MTS/IEEE Seattle OCEANS 2010
The standard-target method used to calibrate scientific echo sounders and other scientific sonars by a single, solid elastic sphere is being adapted to acoustic backscatter (ABS) systems. Its first application, to the AQUAscat 1000, is described. The on-axis sensitivity and directional properties of transducer beams at three operating frequencies, nominally...
Modeling methods
Richard W. Healy
2010, Book chapter, Estimating groundwater recharge
Simulation models are widely used in all types of hydrologic studies, and many of these models can be used to estimate recharge. Models can provide important insight into the functioning of hydrologic systems by identifying factors that influence recharge. The predictive capability of models can be used to evaluate how...
NetCDF-CF-OPeNDAP: Standards for ocean data interoperability and object lessons for community data standards processes
Steven C. Hankin, Jon D. Blower, Thierry Carval, Kenneth S. Casey, Craig Donlon, Olivier Lauret, Thomas Loubrieu, Ashwanth Srinivasan, Joaquin Trinanes, Oystein Godoy, Roy Mendelssohn, Richard P. Signell, Jeff de La Beaujardiere, Peter Cornillon, Frederique Blanc, Russ Rew, Jack Harlan
Julie Hall, D.E. Harrison, Detlef Stammer, editor(s)
2010, Conference Paper, Proceedings of OceanObs'09: Sustained Ocean Observations and Information for Society
It is generally recognized that meeting society's emerging environmental science and management needs will require the marine data community to provide simpler, more effective and more interoperable access to its data. There is broad agreement, as well, that data standards are the bedrock upon which interoperability will be built. The...
Wind River water restoration, Annual report November 2008 to October 2009.
P.J. Connolly, I.G. Jezorek, C.S. Munz
2010, Report
This report summarizes work completed by U.S. Geological Survey’s Columbia River Research Laboratory (USGS-CRRL) in the Wind River subbasin during the period November 2008 through October 2009 under Bonneville Power Administration (BPA) contract 41038. Long term research in the Wind River has focused on assessments of steelhead/rainbow trout Oncorhynchus...
Protocol for statistical analysis of vegetation changes at Catoctin Mountain Park
Jeff S. Hatfield, Cairn Krafft
2010, Natural Resource Report NPS/NCR/NCRO/NRTR2010/001
Vegetation data collected at Catoctin Mountain Park, Maryland, in a split-panel rotation design during 2004-2009 were analyzed for differences among three regions within the park and among years. Six plots were paired with plots fenced to exclude white-tailed deer (Odocoileus virginianus), and differences between open and exclosed plots were...
Computational modeling of bedform evolution in rivers with implications for predictions of flood stage and bed evolution
Jonathan M. Nelson, Yasuyuki Shimizu, Sanjay Giri, Richard R. McDonald
2010, Conference Paper, Proceedings of the 4th Federal Interagency Hydrologic Modeling Conference and the 9th Federal Interagency Sedimentation Conference
Uncertainties in flood stage prediction and bed evolution in rivers are frequently associated with the evolution of bedforms over a hydrograph. For the case of flood prediction, the evolution of the bedforms may alter the effective bed roughness, so predictions of stage and velocity based on assuming bedforms retain the...
Comparison of aquifer characterization approaches through steady state groundwater model validation: A controlled laboratory sandbox study
W.A. Illman, J. Zhu, A.J. Craig, D. Yin
2010, Water Resources Research (46)
Groundwater modeling has become a vital component to water supply and contaminant transport investigations. An important component of groundwater modeling under steady state conditions is selecting a representative hydraulic conductivity (K) estimate or set of estimates which defines the K field of the studied region. Currently, there are a number...
Comparison of XAD with other dissolved lignin isolation techniques and a compilation of analytical improvements for the analysis of lignin in aquatic settings
Robert G. M. Spencer, George R. Aiken, Rachael Y. Dyda, Kenna D. Butler, Brian A. Bergamaschi, Peter J. Hernes
2010, Organic Geochemistry (41) 445-453
This manuscript highlights numerous incremental improvements in dissolved lignin measurements over the nearly three decades since CuO oxidation of lignin phenols was first adapted for environmental samples. Intercomparison of the recovery efficiency of three common lignin phenol concentration and isolation techniques, namely XAD, C18with both CH3OH (C18M) and CH3CN (C18A)...
Determination of stress parameters for eight well-recorded earthquakes in eastern North America
D.M. Boore, K.W. Campbell, G. M. Atkinson
2010, Bulletin of the Seismological Society of America (100) 1632-1645
We determined the stress parameter, Δσ, for the eight earthquakes studied by Atkinson and Boore (2006), using an updated dataset and a revised point-source stochastic model that captures the effect of a finite fault. We consider four geometrical-spreading functions, ranging from 1/R at all distances to two- or three-part functions....
Paradigms and proboscideans in the southern Great Lakes region, USA
J.J. Saunders, E.C. Grimm, C.C. Widga, G.D. Campbell, B. Brandon Curry, D.A. Grimley, P.R. Hanson, J.P. McCullum, J.S. Oliver, J.D. Treworgy
2010, Quaternary International (217) 175-187
Thirteen new chronometric dates for Illinois proboscideans are considered in relation to well-dated pollen records from northeastern and central Illinois. These dates span an interval from 21,228 to 12,944 cal BP. When compared to pollen spectra, it is evident that Mammut americanum inhabited spruce (Picea) and black ash (Fraxinus nigra)...
Mapping elevations of tidal wetland restoration sites in San Francisco Bay: Comparing accuracy of aerial lidar with a singlebeam echosounder
N.D. Athearn, John Y. Takekawa, B. Jaffe, B.J. Hattenbach, A.C. Foxgrover
2010, Journal of Coastal Research (26) 312-319
The southern edge of San Francisco Bay is surrounded by former salt evaporation ponds, where tidal flow has been restricted since the mid to late 1890s. These ponds are now the focus of a large wetland restoration project, and accurate measurement of current pond bathymetry and adjacent mud flats has...
Dynamics and spatio-temporal variability of environmental factors in Eastern Australia using functional principal component analysis
J.K. Szabo, E.M. Fedriani, M. M. Segovia-Gonzalez, L.B. Astheimer, M.J. Hooper
2010, Journal of Biological Systems (18) 763-785
This paper introduces a new technique in ecology to analyze spatial and temporal variability in environmental variables. By using simple statistics, we explore the relations between abiotic and biotic variables that influence animal distributions. However, spatial and temporal variability in rainfall, a key variable in ecological studies, can cause difficulties...
Santa Barbara Basin diatom and silicoflagellate response to global climate anomalies during the past 2200 years
J.A. Barron, D. Bukry, D. Field
2010, Quaternary International (215) 34-44
Santa Barbara Basin (SBB) diatom and silicoflagellate assemblages are quantified from a box core record spanning AD 1940-2001 and an Ocean Drilling Program Hole 893A record from ???220 BC to AD 1880. The combined relative abundance of the diatoms Fragilariopsis doliolus and Nitzschia interrupteseriata from continuous two-year sampling intervals in...
Post-eruption legacy effects and their implications for long-term recovery of the vegetation on Kasatochi Island, Alaska
Stephen S. Talbot, Sandra Looman Talbot, Lawrence R. Walker
2010, Arctic, Antarctic, and Alpine Research (42) 285-296
We studied the vegetation of Kasatochi Island, central Aleutian Islands, to provide a general field assessment regarding the survival of plants, lichens, and fungi following a destructive volcanic eruption that occurred in 2008. Plant community data were analyzed using multivariate methods to explore the relationship between pre- and post-eruption plant...
Locating non-volcanic tremor along the San Andreas Fault using a multiple array source imaging technique
T. Ryberg, C.H. Haberland, G. S. Fuis, W.L. Ellsworth, D.R. Shelly
2010, Geophysical Journal International (183) 1485-1500
Non-volcanic tremor (NVT) has been observed at several subduction zones and at the San Andreas Fault (SAF). Tremor locations are commonly derived by cross-correlating envelope-transformed seismic traces in combination with source-scanning techniques. Recently, they have also been located by using relative relocations with master events, that is low-frequency earthquakes that...