Stratigraphic evidence for the role of lake spillover in the inception of the lower Colorado River in southern Nevada and western Arizona
P.K. House, P. A. Pearthree, M. E. Perkins
2008, Conference Paper, Special Paper of the Geological Society of America
Late Miocene and early Pliocene sediments exposed along the lower Colorado River near Laughlin, Nevada, contain evidence that establishment of this reach of the river after 5.6 Ma involved flooding from lake spillover through a bedrock divide between Cottonwood Valley to the north and Mohave Valley to the south. Lacustrine...
Quaternary geology and sedimentary processes in the vicinity of Six Mile Reef, eastern Long Island Sound
L.J. Poppe, S.J. Williams, M. S. Moser, N.A. Forfinski, H.F. Stewart, E. F. Doran
2008, Journal of Coastal Research (24) 255-266
Six Mile Reef, a sandy, 22-m-high shoal trending east-west and located about 7.8 km off the Connecticut coast, has a core of postglacial marine deltaic deposits mantled by tidally reworked modern sediments. Sedimentary environments off the eastern end of the shoal are characterized by processes associated with long-term erosion or...
Biodynamic modeling of PCB uptake by Macoma balthica and Corbicula fluminea from sediment amended with activated carbon
Pamela B. McLeod, S. N. Luoma, R.G. Luthy
2008, Environmental Science & Technology (42) 484-490
Activated carbon amendment was assessed in the laboratory as a remediation strategy for freshwater sediment contaminated with polychlorinated biphenyls (PCBs) from the Grasse River (near Massena, NY). Three end points were evaluated: aqueous equilibrium PCB concentration, uptake into semipermeable membrane devices (SPMDs), and 28-day bioaccumulation in the clam Corbicula fluminea....
Deformation and rupture of the oceanic crust may control growth of Hawaiian volcanoes
J.-L. Got, V. Monteiller, J. Monteux, R. Hassani, P. Okubo
2008, Nature (451) 453-456
Hawaiian volcanoes are formed by the eruption of large quantities of basaltic magma related to hot-spot activity below the Pacific Plate. Despite the apparent simplicity of the parent process - emission of magma onto the oceanic crust - the resulting edifices display some topographic complexity. Certain features, such as rift...
Characterizing an "uncharacteristics" ETS event in northern Cascadia
K. Wang, H. Dragert, H. Kao, E. Roeloffs
2008, Geophysical Research Letters (35)
GPS and borehole strainmeter data allowed the detection and model characterization of a slow slip event in northern Cascadia in November 2006 accompanying a brief episode of seismic tremor. The event is much smaller in area and duration than other well-known ETS events in northern Cascadia but is strikingly similar...
Prominent pancreatic endocrinopathy and altered control of food intake disrupt energy homeostasis in prion diseases
J. D. Bailey, J.G. Berardinelli, Tonie E. Rocke, R. A. Bessen
2008, Journal of Endocrinology (197) 251-263
Prion diseases are fatal neurodegenerative diseases that can induce endocrinopathies. The basis of altered endocrine function in prion diseases is not well understood, and the purpose of this study was to investigate the spatiotemporal relationship between energy homeostasis and prion infection in hamsters inoculated with either the 139H strain of...
Is there enough sand? Evaluating the fate of Grand Canyon sandbars
S.A. Wright, J. C. Schmidt, Theodore S. Melis, D.J. Topping, D. M. Rubin
2008, GSA Today (18) 4-10
Large dams have the potential to dramatically alter the flow regime, geomorphology, and aquatic ecosystem of downstream river reaches. Development of flow release regimes in order to meet multiple objectives is a challenge facing dam operators, resource managers, and scientists. Herein, we review previous work and present new analyses related...
Characteristics of mangrove swamps managed for mosquito control in eastern Florida, USA
B. Middleton, D. Devlin, E. Proffitt, Karen McKee, K.F. Cretini
2008, Marine Ecology Progress Series (371) 117-129
Manipulations of the vegetation and hydrology of wetlands for mosquito control are common worldwide, but these modifications may affect vital ecosystem processes. To control mosquitoes in mangrove swamps in eastern Florida, managers have used rotational impoundment management (RIM) as an alternative to the worldwide practice of mosquito ditching. Levees surround...
Projected long-term response of Southeastern birds to forest management
M.S. Mitchell, M. J. Reynolds-Hogland, M.L. Smith, P.B. Wood, J.A. Beebe, P.D. Keyser, C. Loehle, C.J. Reynolds, P. Van Deusen, D. White Jr.
2008, Forest Ecology and Management (256) 1884-1896
Numerous studies have explored the influence of forest management on avian communities empirically, but uncertainty about causal relationships between landscape patterns and temporal dynamics of bird communities calls into question how observed historical patterns can be projected into the future, particularly to assess consequences of differing management alternatives. We used...
GSTARS computer models and their applications, Part II: Applications
F.J.M. Simoes, C.T. Yang
2008, International Journal of Sediment Research (23) 299-315
In part 1 of this two-paper series, a brief summary of the basic concepts and theories used in developing the Generalized Stream Tube model for Alluvial River Simulation (GSTARS) computer models was presented. Part 2 provides examples that illustrate some of the capabilities of the GSTARS models and how they...
Aseismic slip and fault-normal strain along the central creeping section of the San Andreas fault
F. Rolandone, R. Burgmann, D.C. Agnew, I.A. Johanson, D.C. Templeton, M. A. d'Alessio, S.J. Titus, C. DeMets, B. Tikoff
2008, Geophysical Research Letters (35)
We use GPS data to measure the aseismic slip along the central San Andreas fault (CSAF) and the deformation across adjacent faults. Comparison of EDM and GPS data sets implies that, except for small-scale transients, the fault motion has been steady over the last 40 years. We add 42 new...
Do non-native plant species affect the shape of productivity-diversity relationships?
J.M. Drake, E.E. Cleland, M. C. Horner-Devine, E. Fleishman, C. Bowles, M. D. Smith, K. Carney, S. Emery, J. Gramling, D.B. Vandermast, J.B. Grace
2008, American Midland Naturalist (159) 55-66
The relationship between ecosystem processes and species richness is an active area of research and speculation. Both theoretical and experimental studies have been conducted in numerous ecosystems. One finding of these studies is that the shape of the relationship between productivity and species richness varies considerably among ecosystems and at...
Hierarchical modeling of bycatch rates of sea turtles in the western North Atlantic
B. Gardner, P.J. Sullivan, S. Epperly, S.J. Morreale
2008, Endangered Species Research (5)
Previous studies indicate that the locations of the endangered loggerhead Caretta caretta and critically endangered leatherback Dermochelys coriacea sea turtles are influenced by water temperatures, and that incidental catch rates in the pelagic longline fishery vary by region. We present a Bayesian hierarchical model to examine the effects of environmental...
Evaluation of MODIS NDVI and NDWI for vegetation drought monitoring using Oklahoma Mesonet soil moisture data
Yingxin Gu, E. Hunt, B. Wardlow, J.B. Basara, Jesslyn F. Brown, J. P. Verdin
2008, Geophysical Research Letters (35) 1-5
The evaluation of the relationship between satellite-derived vegetation indices (normalized difference vegetation index and normalized difference water index) and soil moisture improves our understanding of how these indices respond to soil moisture fluctuations. Soil moisture deficits are ultimately tied to drought stress on plants. The diverse terrain and climate of...
Numerical simulation of the paleohydrology of glacial Lake Oshkosh, eastern Wisconsin, USA
J.A. Clark, K.M. Befus, T.S. Hooyer, P.W. Stewart, T.D. Shipman, C.T. Gregory, D.J. Zylstra
2008, Quaternary Research (69) 117-129
Proglacial lakes, formed during retreat of the Laurentide ice sheet, evolved quickly as outlets became ice-free and the earth deformed through glacial isostatic adjustment. With high-resolution digital elevation models (DEMs) and GIS methods, it is possible to reconstruct the evolution of surface hydrology. When a DEM deforms through time as...
Monitoring a supervolcano in repose: Heat and volatile flux at the yellostone caldera
J. B. Lowenstern, S. Hurwitz
2008, Elements (4) 35-40
Although giant calderas ("supervolcanoes") may slumber for tens of thousands of years between eruptions, their abundant earthquakes and crustal deformation reveal the potential for future upheaval. Any eventual supereruption could devastate global human populations, so these systems must be carefully scrutinized. Insight into dormant but restless calderas can be gained...
The relative contribution of processes driving variability in flow, shear, and turbidity over a fringing coral reef: West Maui, Hawaii
C. D. Storlazzi, B. E. Jaffe
2008, Estuarine, Coastal and Shelf Science (77) 549-564
High-frequency measurements of waves, currents and water column properties were made on a fringing coral reef off northwest Maui, Hawaii, for 15 months between 2001 and 2003 to aid in understanding the processes governing flow and turbidity over a range of time scales and their contributions to annual budgets. The...
M-log A observations for recent large earthquakes
Thomas C. Hanks, W. H. Bakun
2008, Bulletin of the Seismological Society of America (98) 490-494
Using a magnitude (M)-log area (A) dataset augmented with seven large (M > 7.0) earthquakes occurring since Wells and Coppersmith (1994), this short note assesses the current validity of the bilinear M-log A relations for continental, strike-slip earthquakes proposed by Hanks and Bakun (2002), in particular the L-model scaling at...
Proximate cues for a short-distance migratory species: An application of survival analysis
J. Meunier, R. Song, R.S. Lutz, D. E. Andersen, K.E. Doherty, J.G. Bruggink, E. Oppelt
2008, Journal of Wildlife Management (72) 440-448
Investigation of bird migration has often highlighted the importance of external factors in determining timing of migration However, little distinction has been made between short- and long-distance migrants and between local and flight birds (passage migrants) in describing migration chronology. In addition, measures of food abundance as a proximate factor...
Quantile regression applied to spectral distance decay
D. Rocchini, B.S. Cade
2008, IEEE Geoscience and Remote Sensing Letters (5) 640-643
Remotely sensed imagery has long been recognized as a powerful support for characterizing and estimating biodiversity. Spectral distance among sites has proven to be a powerful approach for detecting species composition variability. Regression analysis of species similarity versus spectral distance allows us to quantitatively estimate the amount of turnover in...
Application of environmental groundwater tracers at the Sulphur Bank Mercury Mine, California, USA
M.A. Engle, F. Goff, D.G. Jewett, G.J. Reller, J.B. Bauman
2008, Hydrogeology Journal (16) 559-573
Boron, chloride, sulfate, ??D, ??18O, and 3H concentrations in surface water and groundwater samples from the Sulphur Bank Mercury Mine (SBMM), California, USA were used to examine geochemical processes and provide constraints on evaporation and groundwater flow. SBMM is an abandoned sulfur and mercury mine with an underlying hydrothermal system,...
Great Basin paleontological database
N. Zhang, R. B. Blodgett, A. H. Hofstra
2008, Geosphere (4) 520-535
The U.S. Geological Survey has constructed a paleontological database for the Great Basin physiographic province that can be served over the World Wide Web for data entry, queries, displays, and retrievals. It is similar to the web-database solution that we constructed for Alaskan paleontological data (www.alaskafossil.org). The first phase of...
Den-site characteristics of black bears in Rocky Mountain National Park, Colorado
R.A. Baldwin, Louis C. Bender
2008, Journal of Wildlife Management (72) 1717-1724
We compared historic (1985-1992) and contemporary (2003-2006) black bear (Ursus americanus) den locations in Rocky Mountain National Park (RMNP), Colorado, USA, for habitat and physiographic attributes of den sites and used maximum entropy modeling to determine which factors were most influential in predicting den-site locations. We observed variability in the...
Seabed mapping and characterization of sediment variability using the usSEABED data base
J.A. Goff, C.J. Jenkins, Williams S. Jeffress
2008, Continental Shelf Research (28) 614-633
We present a methodology for statistical analysis of randomly located marine sediment point data, and apply it to the US continental shelf portions of usSEABED mean grain size records. The usSEABED database, like many modern, large environmental datasets, is heterogeneous and interdisciplinary. We statistically test the database as a source...
Overcompensatory response of a smallmouth bass (Micropterus dolomieu) population to harvest: Release from competition?
E.F. Zipkin, P.J. Sullivan, E.G. Cooch, C.E. Kraft, B.J. Shuter, B.C. Weidel
2008, Canadian Journal of Fisheries and Aquatic Sciences (65) 2279-2292
An intensive seven-year removal of adult, juvenile, and young-of-the-year smallmouth bass (Micropterus dolomieu) from a north temperate lake (Little Moose Lake, New York, USA) resulted in an increase in overall population abundance, primarily due to increased abundance of immature individuals. We developed a density-dependent, stage-structured model to examine conditions under...
