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Page 890, results 22226 - 22250

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Publication Extents

Not all publications have extents, not all extents are completely accurate
USGS assessment of undiscovered oil and gas resources for the Oligocene Frio and Anahuac formations, U.S. Gulf of Mexico coastal plain and state waters: Review of assessment units
Sharon M. Swanson, Alexander W. Karlsen, Peter D. Warwick
Lorcan Kennan, James Pindell, Norman C. Rosen, editor(s)
2007, Conference Paper, The Paleogene of the Gulf of Mexico and Caribbean basins: Processes, events, and petroleum systems
The Oligocene Frio and Anahuac formations were examined by the U.S. Geological Survey (USGS) as part of an assessment of technically recoverable undiscovered conventional and unconventional hydrocarbon resources in Paleogene and Neogene strata underlying the U.S. Gulf of Mexico Coastal Plain and state waters. Work included the identification of structural,...
Automated classifications of topography from DEMs by an unsupervised nested-means algorithm and a three-part geometric signature
J. Iwahashi, R.J. Pike
2007, Geomorphology (86) 409-440
An iterative procedure that implements the classification of continuous topography as a problem in digital image-processing automatically divides an area into categories of surface form; three taxonomic criteria–slope gradient, local convexity, and surface texture–are calculated from a square-grid digital elevation model (DEM)....
Prime candidate earth targets for the post-launch radiometric calibration of space-based optical imaging instruments
P.M. Teillet, J. A. Barsi, G. Chander, K. J. Thome
2007, Conference Paper, Proceedings of SPIE - The International Society for Optical Engineering
This paper provides a comprehensive list of prime candidate terrestrial targets for consideration as benchmark sites for the post-launch radiometric calibration of space-based instruments. The key characteristics of suitable sites are outlined primarily with respect to selection criteria, spatial uniformity, and temporal stability. The establishment and utilization of such benchmark...
Generating an image of dispersive energy by frequency decomposition and slant stacking
J. Xia, Y. Xu, R. D. Miller
2007, Pure and Applied Geophysics (164) 941-956
We present a new algorithm for calculating an image of dispersive energy in the frequency-velocity (f-v) domain. The frequency decomposition is first applied to a shot gather in the offset-time domain to stretch impulsive data into pseudo-vibroseis data or frequency-swept data. Because there is a deterministic relationship between frequency and...
Statistical analysis of water-quality data containing multiple detection limits II: S-language software for nonparametric distribution modeling and hypothesis testing
L. Lee, D. Helsel
2007, Computers & Geosciences (33) 696-704
Analysis of low concentrations of trace contaminants in environmental media often results in left-censored data that are below some limit of analytical precision. Interpretation of values becomes complicated when there are multiple detection limits in the data-perhaps as a result of changing analytical precision over time. Parametric and semi-parametric methods,...
Regression models for estimating coseismic landslide displacement
R.W. Jibson
2007, Engineering Geology (91) 209-218
Newmark's sliding-block model is widely used to estimate coseismic slope performance. Early efforts to develop simple regression models to estimate Newmark displacement were based on analysis of the small number of strong-motion records then available. The current availability of a much larger set of strong-motion records dictates that these regression...
Reconstructing late Cenozoic stream gradients from high-level chert gravels in central Eastern Kansas
J.W. Harbaugh, D. F. Merriam, H.H. Howard
2007, Current Research in Earth Sciences (253)
Interpreting the evolution of Kansas' landscape east of the Flint Hills provides major challenges. In the Neogene (late Tertiary) and perhaps part of the Pleistocene, streams transported a variety of sedimentary materials, including chert gravels derived from the Flint Hills. Gentle intermittent uplift stimulated the system system to cut down,...
Late Quaternary paleoenvironments of an ephemeral wetland in North Dakota, USA: Relative interactions of ground-water hydrology and climate change
C.H. Yansa, W.E. Dean, E.C. Murphy
2007, Journal of Paleolimnology (38) 441-457
This study of fossils (pollen, plant macrofossils, stomata and fish) and sediments (lithostratigraphy and geochemistry) from the Wendel site in North Dakota, USA, emphasizes the importance of considering ground-water hydrology when deciphering paleoclimate signals from lakes in postglacial landscapes. The Wendel site was a paleolake from about 11,500 14C yr...
Analysis of Alaskan burn severity patterns using remotely sensed data
P.A. Duffy, J. Epting, J.M. Graham, T.S. Rupp, A. D. McGuire
2007, International Journal of Wildland Fire (16) 277-284
Wildland fire is the dominant large-scale disturbance mechanism in the Alaskan boreal forest, and it strongly influences forest structure and function. In this research, patterns of burn severity in the Alaskan boreal forest are characterised using 24 fires. First, the relationship between burn severity and area burned is quantified using...
Bacteriological water quality in and around Lake Pontchartrain following Hurricanes Katrina and Rita
Dennis K. Demcheck, Donald M. Stoeckel, Rebecca N. Bushon, David S. Blehert, Daniel J. Hippe
2007, Circular 1306-7H
Following the Louisiana landfalls of Katrina on August 29 and Rita on September 24, 2005, the local population and the American public were concerned about the effects the hurricanes might have on water quality in Lake Pontchartrain. The lake is a major recreational resource for the region and an important...
High-resolution proxy record of Holocene climate from a loess section in Southwestern Nebraska, USA
X. Miao, J.A. Mason, W.C. Johnson, Hongfang Wang
2007, Palaeogeography, Palaeoclimatology, Palaeoecology (245) 368-381
Multi-proxy analysis was used to produce a high-resolution paleoclimatic record from an exceptionally thick section of the Holocene Bignell Loess near Wauneta, Southwestern Nebraska, in the central Great Plains. The Wauneta section has excellent age control, based on optically stimulated luminescence (OSL) and radiocarbon dating, and records multiple episodes of...
Faunal re-evaluation of Mid-Pliocene conditions in the western equatorial Pacific
H. Dowsett
2007, Micropaleontology (53) 447-456
Mid-Pliocene low-latitude Pacific faunal (planktic foraminifer) sea surface temperature (SST) estimates are normally based upon the Modern Analog Technique (MAT). In the Eastern equatorial Pacific (EEP), where upwelling of cool water predominates, MAT can be used to discern both cooling and warming in Neogene records. SST today is ???30??C in...
FFT-enhanced IHS transform method for fusing high-resolution satellite images
Y. Ling, M. Ehlers, E.L. Usery, M. Madden
2007, ISPRS Journal of Photogrammetry and Remote Sensing (61) 381-392
Existing image fusion techniques such as the intensity-hue-saturation (IHS) transform and principal components analysis (PCA) methods may not be optimal for fusing the new generation commercial high-resolution satellite images such as Ikonos and QuickBird. One problem is color distortion in the fused image, which causes visual changes as well as...
Evasion of added isotopic mercury from a northern temperate lake
G. Southworth, S. Lindberg, H. Hintelmann, M. Amyot, A. Poulain, M. Bogle, M. Peterson, J. Rudd, R. Harris, K. Sandilands, David P. Krabbenhoft, Mark L. Olsen
2007, Environmental Toxicology and Chemistry (26) 53-60
Isotopically enriched Hg (90% 202Hg) was added to a small lake in Ontario, Canada, at a rate equivalent to approximately threefold the annual direct atmospheric deposition rate that is typical of the northeastern United States. The Hg spike was thoroughly mixed into the epilimnion in nine separate events at two-week...
Assessment of fecal pollution sources in a small northern-plains watershed using PCR and phylogenetic analyses of Bacteroidetes 16S rRNA gene
R. Lamendella, J.W.S. Domingo, D.B. Oerther, J. R. Vogel, D. M. Stoeckel
2007, FEMS Microbiology Ecology (59) 651-660
We evaluated the efficacy, sensitivity, host-specificity, and spatial/temporal dynamics of human- and ruminant-specific 16S rRNA gene Bacteroidetes markers used to assess the sources of fecal pollution in a fecally impacted watershed. Phylogenetic analyses of 1271 fecal and environmental 16S rRNA gene clones were also performed to study the diversity of...
Individual dietary specialization and dive behaviour in the California sea otter: Using archival time-depth data to detect alternative foraging strategies
M. T. Tinker, D.P. Costa, J. A. Estes, N. Wieringa
2007, Deep-Sea Research Part II: Topical Studies in Oceanography (54) 330-342
The existence of individual prey specializations has been reported for an ever-growing number of taxa, and has important ramifications for our understanding of predator-prey dynamics. We use the California sea otter population as a case study to validate the use of archival time-depth data to detect and measure differences in...
Characterization of methane hydrate host sediments using synchrotron-computed microtomography (CMT)
K.W. Jones, H. Feng, S. Tomov, W.J. Winters, M. Prodanovic, D. Mahajan
2007, Journal of Petroleum Science and Engineering (56) 136-145
The hydrate-sediment interaction is an important aspect of gas hydrate studies that needs further examination. We describe here the applicability of the computed microtomography (CMT) technique that utilizes an intense X-ray synchrotron source to characterize sediment samples, two at various depths from the Blake Ridge area (a well-known hydrate-prone region)...
Pumping-induced drawdown and stream depletion in a leaky aquifer system
J.J. Butler Jr., X. Zhan, V.A. Zlotnik
2007, Ground Water (45) 178-186
The impact of ground water pumping on nearby streams is often estimated using analytic models of the interconnected stream-aquifer system. A common assumption of these models is that the pumped aquifer is underlain by an impermeable formation. A new semianalytic solution for drawdown and stream depletion has been developed that...
Remote camera-trap methods and analyses reveal impacts of rangeland management on Namibian carnivore communities
M. J. Kauffman, M. Sanjayan, J. Lowenstein, A. Nelson, R.M. Jeo, K.R. Crooks
2007, Oryx (41) 70-78
Assessing the abundance and distribution of mammalian carnivores is vital for understanding their ecology and providing for their long-term conservation. Because of the difficulty of trapping and handling carnivores many studies have relied on abundance indices that may not accurately reflect real abundance and distribution patterns. We developed statistical analyses...
Seasonal nutrient and plankton dynamics in a physical-biological model of Crater Lake
K. Fennel, R. Collier, G. Larson, G. Crawford, E. Boss
2007, Hydrobiologia (574) 265-280
A coupled 1D physical-biological model of Crater Lake is presented. The model simulates the seasonal evolution of two functional phytoplankton groups, total chlorophyll, and zooplankton in good quantitative agreement with observations from a 10-year monitoring study. During the stratified period in summer and early fall the model displays a marked...
Dynamics of newly established elk populations
G.A. Sargeant, M.W. Oehler Sr.
2007, Journal of Wildlife Management (71) 1141-1148
The dynamics of newly established elk (Cervus elaphus) populations can provide insights about maximum sustainable rates of reproduction, survival, and increase. However, data used to estimate rates of increase typically have been limited to counts and rarely have included complementary estimates of vital rates. Complexities of population dynamics cannot be...
Landscape correlates along mourning dove call-count routes in Mississippi
R.D. Elmore, F. J. Vilella, P.D. Gerard
2007, Journal of Wildlife Management (71) 422-427
Mourning dove (Zenaida macroura) call-count surveys in Mississippi, USA, suggest declining populations. We used available mourning dove call-count data to evaluate long-term mourning dove habitat relationships. Dove routes were located in the Mississippi Alluvial Valley, Deep Loess Province, Mid Coastal Plain, and Hilly Coastal Plain physiographic provinces of Mississippi. We...
Advanced technologies demonstrated by the miniature integrated camera and spectrometer (MICAS) aboard deep space 1
D.H. Rodgers, P.M. Beauchamp, L.A. Soderblom, R. H. Brown, G.-S. Chen, M. Lee, B.R. Sandel, D.A. Thomas, R.T. Benoit, R.V. Yelle
2007, Space Science Reviews (129) 309-326
MICAS is an integrated multi-channel instrument that includes an ultraviolet imaging spectrometer (80-185 nm), two high-resolution visible imagers (10-20 ??rad/pixel, 400-900 nm), and a short-wavelength infrared imaging spectrometer (1250-2600 nm). The wavelength ranges were chosen to maximize the science data that could be collected using existing semiconductor technologies and avoiding...
Costimulatory receptors in jawed vertebrates: Conserved CD28, odd CTLA4 and multiple BTLAs
D. Bernard, J.D. Hansen, Pasquier L. Du, M.-P. Lefranc, A. Benmansour, P. Boudinot
2007, Developmental and Comparative Immunology (31) 255-271
CD28 family of costimulatory receptors is comprised of molecules with a single V-type extracellular Ig domain, a transmembrane and an intracytoplasmic region with signaling motifs. CD28 and cytotoxic T lymphocyte antigen-4 (CTLA4) homologs have been recently identified in rainbow trout. Other sequences similar to mammalian CD28 family members have now...
Three-dimensional P-wave velocity structure derived from local earthquakes at the Katmai group of volcanoes, Alaska
A.D. Jolly, S.C. Moran, S.R. McNutt, D.B. Stone
2007, Journal of Volcanology and Geothermal Research (159) 326-342
The three-dimensional P-wave velocity structure beneath the Katmai group of volcanoes is determined by inversion of more than 10,000 rays from over 1000 earthquakes recorded on a local 18 station short-period network between September 1996 and May 2001. The inversion is well constrained from sea level to about 6 km below...