Polychlorinated dibenzo-p-dioxin (PCDDs) and polychlorinated dibenzofurans (PCDFs) in harbor sediments from Sea Lots, Port-of-Spain, Trinidad and Tobago
A. Mohammed, C. Orazio, P. Peterman, K. Echols, K. Feltz, A. Manoo, D. Maraj, J. Agard
2009, Marine Pollution Bulletin (58) 928-934
[No abstract available]...
Global circulation as the main source of cloud activity on Titan
S. Rodriguez, Stéphane Le Mouélic, P. Rannou, G. Tobie, K. H. Baines, J. W. Barnes, C.A. Griffith, M. Hirtzig, K.M. Pitman, Christophe Sotin, R. H. Brown, B. J. Buratti, R. N. Clark, P. D. Nicholson
2009, Nature (459) 678-682
Clouds on Titan result from the condensation of methane and ethane and, as on other planets, are primarily structured by circulation of the atmosphere. At present, cloud activity mainly occurs in the southern (summer) hemisphere, arising near the pole and at mid-latitudes from cumulus updrafts triggered by surface heating and/or...
Factors influencing coastal cutthroat trout (Oncorhynchus clarkii clarkii) seasonal survival rates: A spatially continuous approach within stream networks
A.M. Berger, R. E. Gresswell
2009, Canadian Journal of Fisheries and Aquatic Sciences (66) 613-632
Mark-recapture methods were used to examine watershed-scale survival of coastal cutthroat trout (Oncorhynchus clarkii clarkii) from two headwater stream networks. A total of 1725 individuals (???100 mm, fork length) were individually marked and monitored seasonally over a 3-year period. Differences in survival were compared among spatial (stream segment, subwatershed, and...
A comparison of seed banks across a sand dune successional gradient at Lake Michigan dunes (Indiana, USA)
S. A. Leicht-Young, N.B. Pavlovic, R. Grundel, K.J. Frohnapple
2009, Plant Ecology (202) 299-308
In habitats where disturbance is frequent, seed banks are important for the regeneration of vegetation. Sand dune systems are dynamic habitats in which sand movement provides intermittent disturbance. As succession proceeds from bare sand to forest, the disturbance decreases. At Indiana Dunes National Lakeshore, we examined the seed banks of...
Projected climate-induced faunal change in the Western Hemisphere
J.J. Lawler, S.L. Shafer, D. White, P. Kareiva, E.P. Maurer, A.R. Blaustein, P. J. Bartlein
2009, Ecology (90) 588-597
Climate change is predicted to be one of the greatest drivers of ecological change in the coming century. Increases in temperature over the last century have clearly been linked to shifts in species distributions. Given the magnitude of projected future climatic changes, we can expect even larger range shifts in...
Use of predictive models and rapid methods to nowcast bacteria levels at coastal beaches
Donna S. Francy
2009, Aquatic Ecosystem Health & Management (12) 177-182
The need for rapid assessments of recreational water quality to better protect public health is well accepted throughout the research and regulatory communities. Rapid analytical methods, such as quantitative polymerase chain reaction (qPCR) and immunomagnetic separation/adenosine triphosphate (ATP) analysis, are being tested but are not yet ready for widespread use.Another...
Thorium abundances on the Aristarchus plateau: Insights into the composition of the Aristarchus pyroclastic glass deposits
Justin Hagerty, D. J. Lawrence, B. R. Hawke, Lisa R. Gaddis
2009, Journal of Geophysical Research E: Planets (114)
Thorium (Th) data from the Lunar Prospector gamma ray spectrometer (LP‐GRS) are used to constrain the composition of lunar pyroclastic glass deposits on top of the Aristarchus plateau. Our goal is to use forward modeling of LP‐GRS Th data to measure the Th abundances on the plateau and then to...
A distal earthquake cluster concurrent with the 2006 explosive eruption of Augustine Volcano, Alaska
M. A. Fisher, N.A. Ruppert, R.A. White, Frederic H. Wilson, D. Comer, R. W. Sliter, F. L. Wong
2009, Tectonophysics (469) 25-36
Clustered earthquakes located 25 km northeast of Augustine Volcano began about 6 months before and ceased soon after the volcano's 2006 explosive eruption. This distal seismicity formed a dense cluster less than 5 km across, in map view, and located in depth between 11 km and 16 km. This seismicity was contemporaneous with sharply increased...
Historical and modern disturbance regimes, stand structures, and landscape dynamics in piñon-juniper vegetation of the western United States
William H. Romme, Craig D. Allen, John D. Bailey, William L. Baker, Brandon T. Bestelmeyer, Peter M. Brown, Karen S. Eisenhart, M. Lisa Floyd, David W. Huffman, Brian F. Jacobs, Richard F. Miller, Esteban H. Muldavin, Thomas W. Swetnam, Robin J. Tausch, Peter J. Weisberg
2009, Rangeland Ecology and Management (62) 203-222
Piñon–juniper is a major vegetation type in western North America. Effective management of these ecosystems has been hindered by inadequate understanding of 1) the variability in ecosystem structure and ecological processes that exists among the diverse combinations of piñons, junipers, and associated shrubs, herbs, and soil organisms; 2) the prehistoric...
Methane sources in gas hydrate-bearing cold seeps: Evidence from radiocarbon and stable isotopes
J. W. Pohlman, J.E. Bauer, E. A. Canuel, K.S. Grabowski, D.L. Knies, C.S. Mitchell, Michael J. Whiticar, R.B. Coffin
2009, Marine Chemistry (115) 102-109
Fossil methane from the large and dynamic marine gas hydrate reservoir has the potential to influence oceanic and atmospheric carbon pools. However, natural radiocarbon (14C) measurements of gas hydrate methane have been extremely limited, and their use as a source and process indicator has not yet been systematically established. In...
Nitrate removal in stream ecosystems measured by 15N addition experiments: Denitrification
P. J. Mulholland, R. O. Hall Jr., D. J. Sobota, W. K. Dodds, S.E.G. Findlay, N. B. Grimm, S. K. Hamilton, W. H. McDowell, J. M. O’Brien, J. L. Tank, L. R. Ashkenas, L. W. Cooper, Clifford N. Dahm, S.V. Gregory, S. L. Johnson, J.L. Meyer, B. J. Peterson, G. C. Poole, H. M. Valett, J.R. Webster, C. P. Arango, J. J. Beaulieu, M. J. Bernot, A. J. Burgin, C. L. Crenshaw, A. M. Helton, L. T. Johnson, B.R. Niederlehner, J. D. Potter, R.W. Sheibley, S.M. Thomasn
2009, Limnology and Oceanography (54) 666-680
We measured denitrification rates using a field 15N-NO- 3 tracer-addition approach in a large, cross-site study of nitrate uptake in reference, agricultural, and suburban-urban streams. We measured denitrification rates in 49 of 72 streams studied. Uptake length due to denitrification (SWden) ranged from 89 m to 184 km (median of...
Recent experimental data may point to a greater role for osmotic pressures in the subsurface
C. E. Neuzil, A.M. Provost
2009, Water Resources Research (45)
Uncertainty about the origin of anomalous fluid pressures in certain geologic settings has caused researchers to take a second look at osmosis, or flow driven by chemical potential differences, as a pressure‐generating process in the subsurface. Interest in geological osmosis has also increased because of an in situ experiment by...
A mactrid bivalve from pleistocene deposits of Lake Russell, Mono Basin, California
R. Hershler, A. S. Jayko
2009, Journal of Paleontology (83) 496-499
[No abstract available]...
Numerical simulation of dune-flat bed transition and stage‐discharge relationship with hysteresis effect
Yasuyuki Shimizu, Sanjay Giri, Satomi Yamaguchi, Jonathan M. Nelson
2009, Water Resources Research (45)
This work presents recent advances on morphodynamic modeling of bed forms under unsteady discharge. This paper includes further development of a morphodynamic model proposed earlier by Giri and Shimizu (2006a). This model reproduces the temporal development of river dunes and accurately replicates the physical properties associated with bed form evolution....
Using nitrogen stable isotopes to detect longdistance movement in a threatened cutthroat trout (Oncorhynchus clarkii utah)
A.J. Sepulveda, W.T. Colyer, W.H. Lowe, M.R. Vinson
2009, Canadian Journal of Fisheries and Aquatic Sciences (66) 672-682
Interior cutthroat trout occupy small fractions of their historic ranges and existing populations often are relegated to headwater habitats. Conservation requires balancing protection for isolated genetically pure populations with restoration of migratory life histories by reconnecting corridors between headwater and mainstem habitats. Identification of alternative life history strategies within a...
Web-client based distributed generalization and geoprocessing
E.B. Wolf, K. Howe
2009, Conference Paper, Proceedings of the International Conference on Advanced Geographic Information Systems and Web Services, GEOWS 2009
Generalization and geoprocessing operations on geospatial information were once the domain of complex software running on high-performance workstations. Currently, these computationally intensive processes are the domain of desktop applications. Recent efforts have been made to move geoprocessing operations server-side in a distributed, web accessible environment. This paper initiates research into...
Vulnerability of a public supply well in a karstic aquifer to contamination
B. G. Katz, W.S. McBride, A.G. Hunt, C. A. Crandall, P. A. Metz, S. M. Eberts, M. P. Berndt
2009, Ground Water (47) 438-452
To assess the vulnerability of ground water to contamination in the karstic Upper Floridan aquifer (UFA), age-dating tracers and selected anthropogenic and naturally occurring compounds were analyzed in multiple water samples from a public supply well (PSW) near Tampa, Florida. Samples also were collected from 28 monitoring wells in the...
Using nitrate to quantify quick flow in a karst aquifer
B.J. Mahler, B.D. Garner
2009, Ground Water (47) 350-360
In karst aquifers, contaminated recharge can degrade spring water quality, but quantifying the rapid recharge (quick flow) component of spring flow is challenging because of its temporal variability. Here, we investigate the use of nitrate in a two-endmember mixing model to quantify quick flow in Barton Springs, Austin, Texas. Historical...
Unique problems associated with seismic analysis of partially gas-saturated unconsolidated sediments
Myung W. Lee, T. S. Collett
2009, Marine and Petroleum Geology (26) 775-781
Gas hydrate stability conditions restrict the occurrence of gas hydrate to unconsolidated and high water-content sediments at shallow depths. Because of these host sediments properties, seismic and well log data acquired for the detection of free gas and associated gas hydrate-bearing sediments often require nonconventional analysis. For example, a conventional...
Shallow seismic structure of Kunlun fault zone in northern Tibetan Plateau, China: Implications for the 2001 M s8.1 Kunlun earthquake
Chun-Yong Wang, Walter D. Mooney, Z. Ding, J. Yang, Z. Yao, H. Lou
2009, Geophysical Journal International (177) 978-1000
The shallow seismic velocity structure of the Kunlun fault zone (KLFZ) was jointly deduced from seismic refraction profiling and the records of trapped waves that were excited by five explosions. The data were collected after the 2001 Kunlun Ms8.1 earthquake in the northern Tibetan Plateau. Seismic phases for the in-line record...
Experimental infection of cliff swallows (Petrochelidon pyrrhonota) with varying doses of West Nile virus
P.T. Oesterle, N.M. Nemeth, Kaci K. VanDalen, H. Sullivan, K.T. Bentler, G.R. Young, R. G. McLean, L. Clark, C. Smeraski, Jeffrey S. Hall
2009, American Journal of Tropical Medicine and Hygiene (81) 1159-1164
Cliff swallows (Petrochelidon pyrrhonota) were inoculated with differing doses of West Nile virus (WNV) to evaluate their potential role as reservoir hosts in nature. Swallows often nest in large colonies in habitats and months associated with high mosquito abundance and early WNV transmission in North America. Additionally, cliff swallow diet...
Using geometrical, textural, and contextual information of land parcels for classification of detailed urban land use
S.-S. Wu, X. Qiu, E.L. Usery, L. Wang
2009, Annals of the Association of American Geographers (99) 76-98
Detailed urban land use data are important to government officials, researchers, and businesspeople for a variety of purposes. This article presents an approach to classifying detailed urban land use based on geometrical, textural, and contextual information of land parcels. An area of 6 by 14 km in Austin, Texas, with...
Comparing approaches for simulating the reactive transport of U(VI) in ground water
G.P. Curtis, M. Kohler, J.A. Davis
2009, Mine Water and the Environment (28) 84-93
The reactive transport of U(VI) in a well-characterized shallow alluvial aquifer at a former U(VI) mill located near Naturita, CO, was predicted for comparative purposes using a surface complexation model (SCM) and a constant K d approach to simulate U(VI) adsorption. The ground water at the site had U(VI) concentrations that...
Ecology and the ratchet of events: Climate variability, niche dimensions, and species distributions
S.T. Jackson, J.L. Betancourt, R.K. Booth, S.T. Gray
2009, Conference Paper, Proceedings of the National Academy of Sciences of the United States of America
Climate change in the coming centuries will be characterized by interannual, decadal, and multidecadal fluctuations superimposed on anthropogenic trends. Predicting ecological and biogeographic responses to these changes constitutes an immense challenge for ecologists. Perspectives from climatic and ecological history indicate that responses will be laden with contingencies, resulting from episodic...
Land crabs as key drivers in tropical coastal forest recruitment
E.S. Lindquist, K. W. Krauss, P.T. Green, D. J. O’Dowd, P.M. Sherman, T. J. Smith III
2009, Biological Reviews (84) 203-223
Plant populations are regulated by a diverse assortment of abiotic and biotic factors that influence seed dispersal and viability, and seedling establishment and growth at the microsite. Rarely does one animal guild exert as significant an influence on different plant assemblages as land crabs. We review three tropical coastal ecosystems-mangroves,...
