A model for radial dike emplacement in composite cones based on observations from Summer Coon volcano, Colorado, USA
Michael P. Poland, W.P. Moats, J.H. Fink
2008, Bulletin of Volcanology (70) 861-875
We mapped the geometry of 13 silicic dikes at Summer Coon, an eroded Oligocene stratovolcano in southern Colorado, to investigate various characteristics of radial dike emplacement in composite volcanoes. Exposed dikes are up to about 7 km in length and have numerous offset segments along their upper peripheries. Surprisingly, most...
Predicting the locations of naturally fishless lakes
Emily Gaenzle Schilling, C.S. Loftin, K.E. Degoosh, Alexander D. Huryn, K.E. Webster
2008, Freshwater Biology (53) 1021-1035
1. Fish have been introduced into many previously fishless lakes throughout North America over the past 100+ years. It is difficult to determine the historical distribution of fishless lakes, however, because these introductions have not always been well-documented. 2. Due to its glacial history and low human population density, the...
Utilizing spectral analysis of coastal discharge computed by a numerical model to determine boundary influence
E.D. Swain, C.D. Langevin, J.D. Wang
2008, Journal of Coastal Research (24) 1418-1429
In the present study, a spectral analysis was applied to field data and a numerical model of southeastern Everglades and northeastern Florida Bay that involved computing and comparing the power spectrum of simulated and measured flows at the primary coastal outflow creek. Four dominant power frequencies, corresponding to the S1,...
Isotope geochemistry of mercury in source rocks, mineral deposits and spring deposits of the California Coast Ranges, USA
C.N. Smith, S.E. Kesler, J.D. Blum, J. J. Rytuba
2008, Earth and Planetary Science Letters (269) 398-406
We present here the first study of the isotopic composition of mercury in rocks, ore deposits, and active spring deposits from the California Coast Ranges, a part of Earth's crust with unusually extensive evidence of mercury mobility and enrichment. The Franciscan Complex and Great Valley Sequence, which form the bedrock...
Joint variability of global runoff and global sea surface temperatures
G.J. McCabe, D.M. Wolock
2008, Journal of Hydrometeorology (9) 816-824
Global land surface runoff and sea surface temperatures (SST) are analyzed to identify the primary modes of variability of these hydroclimatic data for the period 1905-2002. A monthly water-balance model first is used with global monthly temperature and precipitation data to compute time series of annual gridded runoff for the...
Modeling potential habitats for alien species Dreissena polymorpha in continental USA
Li Mingyang, Ju Yunwei, Sunil Kumar, Thomas J. Stohlgren
2008, Acta Ecologica Sinica (28) 4253-4258
The effective measure to minimize the damage of invasive species is to block the potential invasive species to enter into suitable areas. 1864 occurrence points with GPS coordinates and 34 environmental variables from Daymet datasets were gathered, and 4 modeling methods, i.e., Logistic Regression (LR), Classification and Regression Trees (CART),...
Tracking the Archean-Proterozoic suture zone in the northeastern Great Basin, Nevada and Utah
B. D. Rodriguez, J. M. Williams
2008, Geosphere (4) 315-328
It is important to know whether major mining districts in north-central Nevada are underlain by crust of the Archean Wyoming craton, known to contain major orogenic gold deposits or, alternatively, by accreted crust of the Paleoproterozoic Mojave province. Determining the location and orientation of the Archean-Proterozoic suture zone between these...
Trends in abundance of collared lemmings near Cape Churchill, Manitoba, Canada
M.E. Reiter, D. E. Andersen
2008, Journal of Mammalogy (89) 138-144
Regular, multiannual cycles observed in the population abundance of small mammals in many arctic and subarctic ecosystems have stimulated substantial research, particularly among population ecologists. Hypotheses of mechanisms generating regular cycles include predator-prey interactions, limitation of food resources, and migration or dispersal, as well as abiotic factors such as cyclic...
A quantile count model of water depth constraints on Cape Sable seaside sparrows
B.S. Cade, Q. Dong
2008, Journal of Animal Ecology (77) 47-56
1. A quantile regression model for counts of breeding Cape Sable seaside sparrows Ammodramus maritimus mirabilis (L.) as a function of water depth and previous year abundance was developed based on extensive surveys, 1992-2005, in the Florida Everglades. The quantile count model extends linear quantile regression methods to discrete response...
Lake Erie Yellow perch age estimation based on three structures: Precision, processing times, and management implications
C.S. Vandergoot, M.T. Bur, K.A. Powell
2008, North American Journal of Fisheries Management (28) 563-571
Yellow perch Perca flavescens support economically important recreational and commercial fisheries in Lake Erie and are intensively managed. Age estimation represents an integral component in the management of Lake Erie yellow perch stocks, as age-structured population models are used to set safe harvest levels on an annual basis. We compared...
Oxygen isotope geochemistry of the lassen volcanic center, California: Resolving crustal and mantle contributions to continental Arc magmatism
T.C. Feeley, M.A. Clynne, G.S. Winer, W.C. Grice
2008, Journal of Petrology (49) 971-997
This study reports oxygen isotope ratios determined by laser fluorination of mineral separates (mainly plagioclase) from basaltic andesitic to rhyolitic composition volcanic rocks erupted from the Lassen Volcanic Center (LVC), northern California. Plagioclase separates from nearly all rocks have δ18O values (6·1–8·4‰) higher than expected for production of the magmas...
Using an ecological ethics framework to make decisions about the relocation of wildlife
E.D. McCoy, K. Berry
2008, Science and Engineering Ethics (14) 505-521
Relocation is an increasingly prominent conservation tool for a variety of wildlife, but the technique also is controversial, even among conservation practitioners. An organized framework for addressing the moral dilemmas often accompanying conservation actions such as relocation has been lacking. Ecological ethics may provide such a framework and appears to...
Influence of gravel mining and other factors on detection probabilities of Coastal Plain fishes in the Mobile River Basin, Alabama
C.-A. Hayer, E.R. Irwin
2008, Transactions of the American Fisheries Society (137) 1606-1620
We used an information-theoretic approach to examine the variation in detection probabilities for 87 Piedmont and Coastal Plain fishes in relation to instream gravel mining in four Alabama streams of the Mobile River drainage. Biotic and abiotic variables were also included in candidate models. Detection probabilities were heterogeneous across species...
Regional groundwater flow in mountainous terrain: Three‐dimensional simulations of topographic and hydrogeologic controls
Tom Gleeson, Andrew H. Manning
2008, Water Resources Research (44)
This study uses numerical simulations to define the salient controls on regional groundwater flow in 3‐D mountainous terrain by systematically varying topographic and hydrogeologic variables. Topography for idealized multiple‐basin mountainous terrain is derived from geomatic data and literature values. Water table elevation, controlled by the ratio of...
Preliminary radiometric calibration assessment of ALOS AVNIR-2
M. Bouvet, P. Goryl, G. Chander, R. Santer, S. Saunier
2008, Conference Paper, International Geoscience and Remote Sensing Symposium (IGARSS)
This paper summarizes the activities carried out in the frame of the data quality activities of the Advanced Visible and Near Infrared Radiometer type 2 (AVNIR-2) sensor onboard the Advanced Land Observing Satellite (ALOS). Assessment of the radiometric calibration of the AVNIR-2 multi-spectral imager is achieved via three intercomparisons to...
Short-term monitoring of aridland lichen cover and biomass using photography and fatty acids
M. A. Bowker, N.C. Johnson, J. Belnap, G.W. Koch
2008, Journal of Arid Environments (72) 869-878
Biological soil crust (BSC) communities (composed of lichens, bryophytes, and cyanobacteria) may be more dynamic on short-time scales than previously thought, requiring new and informative short-term monitoring techniques. We used repeat digital photography and image analysis, which revealed a change in area of a dominant BSC lichen, Collema tenax. The...
Use of a 15 k gene microarray to determine gene expression changes in response to acute and chronic methylmercury exposure in the fathead minnow Pimephales promelas Rafinesque
R. Klaper, Barbara J. Carter, C.A. Richter, P.E. Drevnick, M.B. Sandheinrich, D. E. Tillitt
2008, Journal of Fish Biology (72) 2207-2280
This study describes the use of a 15 000 gene microarray developed for the toxicological model species, Pimephales promelas, in investigating the impact of acute and chronic methylmercury exposures in male gonad and liver tissues. The results show significant differences in the individual genes that were differentially expressed in response...
Understanding the relationship between audiomagnetotelluric data and models, and borehole data in a hydrological environment
D.K. McPhee, L. Pellerin
2008, Conference Paper, SEG Technical Program Expanded Abstracts
Audiomagnetotelluric (AMT) data and resulting models are analyzed with respect to geophysical and geological borehole logs in order to clarify the relationship between the two methodologies of investigation of a hydrological environment. Several profiles of AMT data collected in basins in southwestern United States are being used for groundwater exploration...
4D volcano gravimetry
Maurizio Battaglia, J. Gottsmann, D. Carbone, J. Fernandez
2008, Geophysics (73) WA3-WA18
Time-dependent gravimetric measurements can detect subsurface processes long before magma flow leads to earthquakes or other eruption precursors. The ability of gravity measurements to detect subsurface mass flow is greatly enhanced if gravity measurements are analyzed and modeled with ground-deformation data. Obtaining the maximum information from microgravity studies requires careful...
Extreme changes in stable hydrogen isotopes and precipitation characteristics in a landfalling Pacific storm
T.B. Coplen, P.J. Neiman, A.B. White, J.M. Landwehr, F.M. Ralph, M. D. Dettinger
2008, Geophysical Research Letters (35)
With a new automated precipitation collector we measured a remarkable decrease of 51??? in the hydrogen isotope ratio (?? 2H) of precipitation over a 60-minute period during the landfall of an extratropical cyclone along the California coast on 21 March 2005. The rapid drop in ??2H occurred as precipitation generation...
Characterization of errors in a coupled snow hydrology-microwave emission model
K.M. Andreadis, D. Liang, L. Tsang, D.P. Lettenmaier, E.G. Josberger
2008, Journal of Hydrometeorology (9) 149-164
Traditional approaches to the direct estimation of snow properties from passive microwave remote sensing have been plagued by limitations such as the tendency of estimates to saturate for moderately deep snowpacks and the effects of mixed land cover within remotely sensed pixels. An alternative approach is to assimilate satellite microwave...
Methane-producing microbial community in a coal bed of the Illinois Basin
D. Strapoc, F.W. Picardal, C. Turich, I. Schaperdoth, J. L. Macalady, J.S. Lipp, Y.-S. Lin, T.F. Ertefai, F. Schubotz, K.-U. Hinrichs, Maria Mastalerz, A. Schimmelmann
2008, Applied and Environmental Microbiology (74) 2424-2432
A series of molecular and geochemical studies were performed to study microbial, coal bed methane formation in the eastern Illinois Basin. Results suggest that organic matter is biodegraded to simple molecules, such as H 2 and CO2, which fuel methanogenesis and the generation of large coal bed methane reserves. Small-subunit...
Influence of perched groundwater on base flow
Richard G. Niswonger, Graham E. Fogg
2008, Water Resources Research (44)
Analysis with a three‐dimensional variably saturated groundwater flow model provides a basic understanding of the interplay between streams and perched groundwater. A simplified, layered model of heterogeneity was used to explore these relationships. Base flow contribution from perched groundwater was evaluated with regard to varying hydrogeologic conditions, including the size...
Temporal variation and the effect of rainfall on metals flux from the historic Beatson mine, Prince William Sound, Alaska, USA
L.L. Stillings, A. L. Foster, R.A. Koski, L. Munk, Wayne C. Shanks III
2008, Applied Geochemistry (23) 255-278
Several abandoned Cu mines are located along the shore of Prince William Sound, AK, where the effect of mining-related discharge upon shoreline ecosystems is unknown. To determine the magnitude of this effect at the former Beatson mine, the largest Cu mine in the region and a Besshi-type massive sulfide ore...
Using the FORE-SCE model to project land-cover change in the southeastern United States
Terry Sohl, Kristi L. Sayler
2008, Ecological Modelling (219) 49-65
A wide variety of ecological applications require spatially explicit current and projected land-use and land-cover data. The southeastern United States has experienced massive land-use change since European settlement and continues to experience extremely high rates of forest cutting, significant urban development, and changes in agricultural land use. Forest-cover patterns and...
