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Page 1771, results 44251 - 44275

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Documenting channel features associated with gas hydrates in the Krishna-Godavari Basin, offshore India
M. Riedel, Timothy S. Collett, Ude Shankar
2011, Marine Geology (279) 1-11
During the India National Gas Hydrate Program (NGHP) Expedition 01 in 2006 significant sand and gas hydrate were recovered at Site NGHP-01-15 within the Krishna–Godavari Basin, East Coast off India. At the drill site NGHP-01-15, a 5–8 m thick interval was found that is characterized by higher sand content than anywhere...
Challenges in identifying sites climatically matched to the native ranges of animal invaders
G.H. Rodda, C. S. Jarnevich, R.N. Reed
2011, PLoS ONE (6)
Background: Species distribution models are often used to characterize a species' native range climate, so as to identify sites elsewhere in the world that may be climatically similar and therefore at risk of invasion by the species. This endeavor provoked intense public controversy over recent attempts to model areas at...
Adaptive finite volume methods with well-balanced Riemann solvers for modeling floods in rugged terrain: Application to the Malpasset dam-break flood (France, 1959)
D.L. George
2011, International Journal for Numerical Methods in Fluids (66) 1000-1018
The simulation of advancing flood waves over rugged topography, by solving the shallow-water equations with well-balanced high-resolution finite volume methods and block-structured dynamic adaptive mesh refinement (AMR), is described and validated in this paper. The efficiency of block-structured AMR makes large-scale problems tractable, and allows the use of accurate and...
Storms, floods, and the science of atmospheric rivers
F.M. Ralph, M. D. Dettinger
2011, Eos, Transactions, American Geophysical Union (92) 265-266
Imagine a stream of water thousands of kilometers long and as wide as the distance between New York City and Washington, D. C., flowing toward you at 30 miles per hour. No, this is not some hypothetical physics problemit is a real river, carrying more water than 7-15 Mississippi Rivers...
Characterizing land surface change and levee stability in the Sacramento-San Joaquin Delta using UAVSAR radar imagery
C. Jones, G. Bawden, S. Deverel, J. Dudas, S. Hensley
2011, Conference Paper, International Geoscience and Remote Sensing Symposium (IGARSS)
The islands of the Sacramento-San Joaquin Delta have been subject to subsidence since they were first reclaimed from the estuary marshlands starting over 100 years ago, with most of the land currently lying below mean sea level. This area, which is the primary water resource of the state of California,...
The stratigraphic filter and bias in measurement of geologic rates
R. Schumer, D. Jerolmack, Brandon McElroy
2011, Geophysical Research Letters (38)
Erosion and deposition rates estimated from the stratigraphic record frequently exhibit a power‐law dependence on measurement interval. This dependence can result from a power‐law distribution of stratigraphic hiatuses. By representing the stratigraphic filter as a stochastic process called a reverse ascending ladder, we describe a likely origin of power‐law hiatuses,...
Unravelling long-term vegetation change patterns in a binational watershed using multitemporal land cover data and historical photography
M.L. Villarreal, Laura M. Norman, Robert Webb, Diane E. Boyer, R.E. Turner
2011, Conference Paper, 2011 6th International Workshop on the Analysis of Multi-Temporal Remote Sensing Images, Multi-Temp 2011 - Proceedings
A significant amount of research conducted in the Sonoran Desert of North America has documented, both anecdotally and empirically, major vegetation changes over the past century due to human land use activities. However, many studies lack coincidental landscape-scale data characterizing the spatial and temporal manifestation of these changes. Vegetation changes...
Structure of the San Fernando Valley region, California: implications for seismic hazard and tectonic history
V.E. Langenheim, T. L. Wright, D. A. Okaya, R.S. Yeats, G. S. Fuis, K. Thygesen, H. Thybo
2011, Geosphere (7) 528-572
Industry seismic reflection data, oil test well data, interpretation of gravity and magnetic data, and seismic refraction deep-crustal profiles provide new perspectives on the subsurface geology of San Fernando Valley, home of two of the most recent damaging earthquakes in southern California. Seismic reflection data provide depths to Miocene–Quaternary horizons;...
Exploring the sensitivity of soil carbon dynamics to climate change, fire disturbance and permafrost thaw in a black spruce ecosystem
J. A. O'Donnell, Jennifer W. Harden, A. David McGuire, V.E. Romanovsky
2011, Biogeosciences (8) 1367-1382
In the boreal region, soil organic carbon (OC) dynamics are strongly governed by the interaction between wildfire and permafrost. Using a combination of field measurements, numerical modeling of soil thermal dynamics, and mass-balance modeling of OC dynamics, we tested the sensitivity of soil OC storage to a suite of individual...
Co-occurrence patterns of trees along macro-climatic gradients and their potential influence on the present and future distribution of Fagus sylvatica L.
E.S. Meier, Thomas C. Edwards Jr., Felix Kienast, M. Dobbertin, N.E. Zimmermann
2011, Journal of Biogeography (38) 371-382
During recent and future climate change, shifts in large-scale species ranges are expected due to the hypothesized major role of climatic factors in regulating species distributions. The stress-gradient hypothesis suggests that biotic interactions may act as major constraints on species distributions under more favourable growing conditions, while climatic constraints may...
A bacterium that can grow by using arsenic instead of phosphorus
Felisa Wolfe-Simon, Jodi S. Blum, T.R. Kulp, Gordon W. Rattray, S.E. Hoeft, J. Pett-Ridge, J.F. Stolz, S.M. Webb, P.K. Weber, P.C.W. Davies, A.D. Anbar, R.S. Oremland
2011, Science (332) 1163-1166
Life is mostly composed of the elements carbon, hydrogen, nitrogen, oxygen, sulfur, and phosphorus. Although these six elements make up nucleic acids, proteins, and lipids and thus the bulk of living matter, it is theoretically possible that some other elements in the periodic table could serve the same functions. Here,...
Predicting carnivore occurrence with noninvasive surveys and occupancy modeling
Robert A. Long, Therese M. Donovan, Paula MacKay, William J. Zielinski, Jeffrey S. Buzas
2011, Landscape Ecology (26) 327-340
Terrestrial carnivores typically have large home ranges and exist at low population densities, thus presenting challenges to wildlife researchers. We employed multiple, noninvasive survey methods—scat detection dogs, remote cameras, and hair snares—to collect detection–nondetection data for elusive American black bears (Ursus americanus), fishers (Martes pennanti), and bobcats (<i...
Tiny intraplate earthquakes triggered by nearby episodic tremor and slip in Cascadia
J.E. Vidale, A.J. Hotovec, A. Ghosh, K. C. Creager, J. Gomberg
2011, Geochemistry, Geophysics, Geosystems (12)
Episodic tremor and slip (ETS) has been observed in many subduction zones, but its mechanical underpinnings as well as its potential for triggering damaging earthquakes have proven difficult to assess. Here we use a seismic array in Cascadia of unprecedented density to monitor seismicity around a moderate 16 day ETS...
Reduction of structural Fe(III) in nontronite by methanogen Methanosarcina barkeri
D. Liu, Hailiang H. Dong, M.E. Bishop, Hongfang Wang, A. Agrawal, S. Tritschler, D. D. Eberl, S. Xie
2011, Geochimica et Cosmochimica Acta (75) 1057-1071
Clay minerals and methanogens are ubiquitous and co-exist in anoxic environments, yet it is unclear whether methanogens are able to reduce structural Fe(III) in clay minerals. In this study, the ability of methanogen Methanosarcina barkeri to reduce structural Fe(III) in iron-rich smectite (nontronite NAu-2) and the relationship between iron reduction and methanogenesis...
Common challenges for ecological modelling: synthesis of facilitated discussions held at the symposia organized for the 2009 conference of the International Society for Ecological Modelling in Quebec City, Canada, (October 6-9, 2009)
Guy R. Larocque, D. Mailly, T.-X. Yue, M. Anand, C. Peng, C. Kazanci, M. Etterson, P. Goethals, S.E. Jorgensen, J.R. Schramski, E.J.B. McIntire, D.J. Marceau, B. Chen, G.Q. Chen, Z.F. Yang, B. Novotna, N. Luckai, Jagtar S. Bhatti, J. Liu, A. Munson, Andrew M. Gordon, J.C. Ascough
2011, Ecological Modelling (222) 2456-2468
The eleven symposia organized for the 2009 conference of the International Society for Ecological Modelling (ISEM 2009) held in Quebec City, Canada, October 6–9, 2009, included facilitated discussion sessions following formal presentations. Each symposium focused on a specific subject, and all the subjects could be classified into three broad categories:...
Status and distribution of the Kittlitz's murrelet Brachyramphus brevirostris in Kenai Fjords, Alaska
Mayumi L. Arimitsu, John F. Piatt, Marc D. Romano, Thomas I. van Pelt
2011, Marine Ornithology: Journal of Seabird Research and Conservation (39) 13-22
The Kittlitz's Murrelet Brachyramphus brevirostris is a candidate species for listing under the US Endangered Species Act because of its apparent declines within core population areas of coastal Alaska. During the summers of 2006-2008, we conducted surveys in marine waters adjacent to Kenai Fjords National Park, Alaska, to estimate the...
Relationship of external fish condition to pathogen prevalence and out-migration survival in juvenile steelhead
Nathan J. Hostetter, A.F. Evans, Daniel D. Roby, K. Collis, M. Hawbecker, B.P. Sandford, D.E. Thompson, F.J. Loge
2011, Transactions of the American Fisheries Society (140) 1158-1171
Understanding how the external condition of juvenile salmonids is associated with internal measures of health and subsequent out‐migration survival can be valuable for population monitoring programs. This study investigated the use of a rapid, nonlethal, external examination to assess the condition of run‐of‐the‐river juvenile steelhead Oncorhynchus mykiss migrating from the Snake River...
Molecular insights into the biology of Greater Sage-Grouse
Sara J. Oyler-McCance, Thomas W. Quinn
2011, Book chapter, Greater Sage-Grouse: Ecology and conservation of a landscape species and its habitats
Recent research on Greater Sage-Grouse (Centrocercus urophasianus) genetics has revealed some important findings. First, multiple paternity in broods is more prevalent than previously thought, and leks do not comprise kin groups. Second, the Greater Sage-Grouse is genetically distinct from the congeneric Gunnison sage-grouse (C. minimus). Third, the Lyon-Mono population in...
Long-term biases in geomagnetic K and aa indices
Jeffrey J. Love
2011, Annales Geophysicae (29) 1365-1375
Analysis is made of the geomagnetic-activity aa index and its source K-index data from groups of ground-based observatories in Britain, and Australia, 1868.0–2009.0, solar cycles 11–23. The K data show persistent biases, especially for high (low) K-activity levels at British (Australian) observatories. From examination of multiple subsets of the K data we infer that the biases are not...
Transitions of interaction outcomes in a uni-directional consumer-resource system
Y. Wang, Donald L. DeAngelis
2011, Journal of Theoretical Biology (280) 43-49
A uni-directional consumer–resource system of two species is analyzed. Our aim is to understand the mechanisms that determine how the interaction outcomes depend on the context of the interaction; that is, on the model parameters. The dynamic behavior of the model is described and, in particular, it is demonstrated that no periodic...
Patterns of coral disease across the Hawaiian Archipelago: Relating disease to environment
G.S. Aeby, G.J. Williams, E.C. Franklin, J. Kenyon, E.F. Cox, S. Coles, Thierry M. Work
2011, PLoS ONE (6)
In Hawaii, coral reefs occur across a gradient of biological (host abundance), climatic (sea surface temperature anomalies) and anthropogenic conditions from the human-impacted reefs of the main Hawaiian Islands (MHI) to the pristine reefs of the northwestern Hawaiian Islands (NWHI). Coral disease surveys were conducted at 142 sites from across...
Geology and petroleum potential of the north and east margins of the Siberian Craton, north of the Arctic Circle
T. R. Klett, C. J. Wandrey, Janet K. Pitman
2011, Geological Society Memoir 413-431
The Siberian Craton consists of crystalline rocks and superimposed Precambrian sedimentary rocks deposited in rift basins. Palaeozoic rocks, mainly carbonates, were deposited along the margins of the craton to form an outwardly younger concentric pattern that underlies an outward-thickening Mesozoic sedimentary section. The north and east margins of the Siberian...
Rain pulse response of soil CO2 exchange by biological soil crusts and grasslands of the semiarid Colorado Plateau, United States
David R. Bowling, Edmund E. Grote, Jayne Belnap
2011, Journal of Geophysical Research G: Biogeosciences (116)
Biological activity in arid grasslands is strongly dependent on moisture. We examined gas exchange of biological soil crusts (biocrusts), the underlying soil biotic community, and the belowground respiratory activity of C3 and C4 grasses over 2 years in southeast Utah, USA. We used soil surface CO2 flux and the amount...
Canine detection of free-ranging brown treesnakes on Guam
Julie A. Savidge, James W. Stanford, Robert Reed, Ginger R. Haddock, Amy A. Yackel Adams
2011, New Zealand Journal of Ecology (35) 174-181
We investigated canine teams (dogs and their handlers) on Guam as a potential tool for finding invasive brown treesnakes (Boiga irregularis) in the wild. Canine teams searched a 40 × 40 m forested area for a snake that had consumed a dead mouse containing a radio-transmitter. To avoid tainting the...
Spatiotemporal earthquake clusters along the North Anatolian fault zone offshore Istanbul
Fatih Bulut, William L. Ellsworth, Marco Bohnhoff, Mustafa Aktar, Georg Dresen
2011, Bulletin of the Seismological Society of America (101) 1759-1768
We investigate earthquakes with similar waveforms in order to characterize spatiotemporal microseismicity clusters within the North Anatolian fault zone (NAFZ) in northwest Turkey along the transition between the 1999 İzmit rupture zone and the Marmara Sea seismic gap. Earthquakes within distinct activity clusters are relocated with cross-correlation derived relative travel...