A comparison of phase inversion and traveltime tomography for processing near-surface refraction traveltimes
Karl J. Ellefsen
2009, Geophysical Journal (74) WCB11-WCB24
With phase inversion, one can estimate subsurface velocities using the phases of first-arriving waves, which are the frequency-domain equivalents of the traveltimes. Phase inversion is modified to make it suitable for processing traveltimes from near-surface refraction surveys. The modifications include parameterizing the model, correcting the observed phases, and selecting the...
An ecological risk assessment of the exposure and effects of 2,4-D acid to rainbow trout (Oncorhyncus mykiss)
James Fairchild, Kevin P. Feltz, Ann Allert, L.C. Sappington, K.J. Nelson, J.A. Valle
2009, Archives of Environmental Contamination and Toxicology (56) 754-760
Numerous state and federal agencies are increasingly concerned with the rapid expansion of invasive, noxious weeds across the United States. Herbicides are frequently applied as weed control measures in forest and rangeland ecosystems that frequently overlap with critical habitats of threatened and endangered fish species. However, there is little published...
Landscape features, standards, and semantics in U.S. national topographic mapping databases
Dalia Varanka
2009, Book, Proceedings of the International Conference on Advanced Geographic Information Systems and Web Services, GEOWS 2009
The objective of this paper is to examine the contrast between local, field-surveyed topographical representation and feature representation in digital, centralized databases and to clarify their ontological implications. The semantics of these two approaches are contrasted by examining the categorization of features by subject domains inherent to national topographic mapping....
Time-series modeling of reservoir effects on river nitrate concentrations
A.L. Schoch, K. E. Schilling, K.-S. Chan
2009, Advances in Water Resources (32) 1197-1205
Saylorville Reservoir is a 24.1 km2 impoundment of the Des Moines River located approximately 10 km north of the City of Des Moines, Iowa, USA. Surface water from the Des Moines River used for drinking water supply is impaired for nitrate-nitrogen. Monthly mean nitrate concentration data collected upstream and downstream...
Interpretation of earthquake-induced landslides triggered by the 12 May 2008, M7.9 Wenchuan earthquake in the Beichuan area, Sichuan Province, China using satellite imagery and Google Earth
H.P. Sato, E. L. Harp
2009, Landslides (6) 153-159
The 12 May 2008 M7.9 Wenchuan earthquake in the People's Republic of China represented a unique opportunity for the international community to use commonly available GIS (Geographic Information System) tools, like Google Earth (GE), to rapidly evaluate and assess landslide hazards triggered by the destructive earthquake and its aftershocks. In...
Uptake rate constants and partition coefficients for vapor phase organic chemicals using semipermeable membrane devices (SPMDs)
W.L. Cranor, D.A. Alvarez, J.N. Huckins, J. D. Petty
2009, Atmospheric Environment (43) 3211-3219
To fully utilize semipermeable membrane devices (SPMDs) as passive samplers in air monitoring, data are required to accurately estimate airborne concentrations of environmental contaminants. Limited uptake rate constants (kua) and no SPMD air partitioning coefficient (Ksa) existed for vapor-phase contaminants. This research was conducted to expand the existing body of...
Near term climate projections for invasive species distributions
C. S. Jarnevich, T.J. Stohlgren
2009, Biological Invasions (11) 1373-1379
Climate change and invasive species pose important conservation issues separately, and should be examined together. We used existing long term climate datasets for the US to project potential climate change into the future at a finer spatial and temporal resolution than the climate change scenarios generally available. These fine scale...
Paleontological interpretations of crater processes and infilling of synimpact sediments from the Chesapeake Bay impact structure
Jean Self-Trail, Lucy E. Edwards, Ronald J. Litwin
2009, Special Paper of the Geological Society of America 633-654
Biostratigraphic analysis of sedimentary breccias and diamictons in the Chesapeake Bay impact structure provides information regarding the timing and processes of late-stage gravitational crater collapse and ocean resurge. Studies of calcareous nannofossil and palynomorph assemblages in the International Continental Scientific Drilling Program (ICDP)-U.S. Geological Survey (USGS) Eyreville A and B...
Reflectance spectroscopy of organic compounds: 1. Alkanes
R. N. Clark, J. M. Curchin, T.M. Hoefen, G.A. Swayze
2009, Journal of Geophysical Research E: Planets (114)
Reflectance spectra of the organic compounds comprising the alkane series are presented from the ultraviolet to midinfrared, 0.35 to 15.5 /??m. Alkanes are hydrocarbon molecules containing only single carbon-carbon bonds, and are found naturally on the Earth and in the atmospheres of the giant planets and Saturn's moon, Titan. This...
Measurement of total Zn and Zn isotope ratios by quadrupole ICP-MS for evaluation of Zn uptake in gills of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss)
R.E. Wolf, A.S. Todd, S. Brinkman, P. J. Lamothe, K. S. Smith, J. F. Ranville
2009, Talanta (80) 676-684
This study evaluates the potential use of stable zinc isotopes in toxicity studies measuring zinc uptake by the gills of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss). The use of stable isotopes in such studies has several advantages over the use of radioisotopes, including cost, ease of handling,...
Assessing the impact of land use change on hydrology by ensemble modeling (LUCHEM). I: Model intercomparison with current land use
L. Breuer, J. A. Huisman, P. Willems, H. Bormann, A. Bronstert, B.F.W. Croke, H.-G. Frede, T. Graff, L. Hubrechts, A.J. Jakeman, G. Kite, J. Lanini, G. Leavesley, D.P. Lettenmaier, G. Lindstrom, J. Seibert, M. Sivapalan, N.R. Viney
2009, Advances in Water Resources (32) 129-146
This paper introduces the project on 'Assessing the impact of land use change on hydrology by ensemble modeling (LUCHEM)' that aims at investigating the envelope of predictions on changes in hydrological fluxes due to land use change. As part of a series of four papers, this paper outlines the motivation...
Source analysis using regional empirical Green's functions: The 2008 Wells, Nevada, earthquake
C. Mendoza, S. Hartzell
2009, Geophysical Research Letters (36)
We invert three-component, regional broadband waveforms recorded for the 21 February 2008 Wells, Nevada, earthquake using a finite-fault methodology that prescribes subfault responses using eight MW∼4 aftershocks as empirical Green's functions (EGFs) distributed within a 20-km by 21.6-km fault area. The inversion identifies a seismic moment of 6.2 x 1024...
Isotopic variability of mercury in ore, mine-waste calcine, and leachates of mine-waste calcine from areas mined for mercury
S.J. Stetson, J. E. Gray, R. B. Wanty, D.L. Macalady
2009, Environmental Science & Technology (43) 7331-7336
The isotopic composition of mercury (Hg) was determined in cinnabar ore, mine-waste calcine (retorted ore), and leachates obtained from water leaching experiments of calcine from two large Hg mining districts in the U.S. This study is the first to report significant mass-dependent Hg isotopic fractionation between cinnabar ore and resultant...
Response of the everglades ridge and slough landscape to climate variability and 20th-century water management
C.E. Bernhardt, Debra A. Willard
2009, Ecological Applications (19) 1723-1738
The ridge and slough landscape of the Florida Everglades consists of a mosaic of linear sawgrass ridges separated by deeper-water sloughs with tree islands interspersed throughout the landscape. We used pollen assemblages from transects of sediment cores spanning sawgrass ridges, sloughs, and ridge-slough transition zones to determine the timing of...
Intercomparison, interpretation, and assessment of spring phenology in North America estimated from remote sensing for 1982-2006
M.A. White, K. M. de Beurs, K. Didan, D.W. Inouye, A.D. Richardson, O.P. Jensen, J. O'Keefe, G. Zhang, R.R. Nemani, Leeuwen W.J.D. van W.J.D., Jesslyn F. Brown, A. de Wit, M. Schaepman, X. Lin, M. Dettinger, A.S. Bailey, J. Kimball, M.D. Schwartz, D. D. Baldocchi, J.T. Lee, W.K. Lauenroth
2009, Global Change Biology (15) 2335-2359
Shifts in the timing of spring phenology are a central feature of global change research. Long-term observations of plant phenology have been used to track vegetation responses to climate variability but are often limited to particular species and locations and may not represent synoptic patterns. Satellite remote sensing is instead...
Spectral distance decay
D. Rocchinl, H. Nagendra, R. Ghate, B.S. Cade
2009, Photogrammetric Engineering and Remote Sensing (75) 1225-1230
Remotely sensed data represents key information for character-izing 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 may allow us to quantitatively estimate how beta-diversity in species changes with respect to spectral...
Supplemental materials for the ICDP-USGS Eyreville A, B, and C core holes, Chesapeake Bay impact structure: Core-box photographs, coring-run tables, and depth-conversion files
C.T. Durand, Lucy E. Edwards, M.L. Malinconico, David S. Powars
2009, Special Paper of the Geological Society of America 115-118
During 2005-2006, the International Continental Scientific Drilling Program and the U.S. Geological Survey drilled three continuous core holes into the Chesapeake Bay impact structure to a total depth of 1766.3 m. A collection of supplemental materials that presents a record of the core recovery and measurement data for the Eyreville...
Water quality characterization in some birimian aquifers of the Birim Basin, Ghana
B.-Y. Bruce, S.M. Yidana, Y. Anku, T. Akabzaa, D. Asiedu
2009, KSCE Journal of Civil Engineering (13) 179-187
The objective of this study was to determine the main controls on the hydrochemistry of groundwater in the study area. Mass balance modeling was used simultaneously with multivariate R-mode hierarchical cluster analysis to determine the significant sources of variation in the hydrochemistry. Two water types have been revealed in this...
Estimating 3D variation in active-layer thickness beneath arctic streams using ground-penetrating radar
T.R. Brosten, J.H. Bradford, J. P. McNamara, M.N. Gooseff, J.P. Zarnetske, W.B. Bowden, M.E. Johnston
2009, Journal of Hydrology (373) 479-486
We acquired three-dimensional (3D) ground-penetrating radar (GPR) data across three stream sites on the North Slope, AK, in August 2005, to investigate the dependence of thaw depth on channel morphology. Data were migrated with mean velocities derived from multi-offset GPR profiles collected across a stream section within each of the...
Estimating avian population size using Bowden's estimator
Duane R. Diefenbach
2009, The Auk (126) 211-217
Avian researchers often uniquely mark birds, and multiple estimators could be used to estimate population size using individually identified birds. However, most estimators of population size require that all sightings of marked birds be uniquely identified, and many assume homogeneous detection probabilities. Bowden's estimator can incorporate sightings of marked birds...
Migratory patterns and population structure among breeding and wintering red-breasted mergansers (Mergus serrator) and common mergansers (M. merganser)
John M. Pearce, K. G. McCracken, Thomas K. Christensen, Y.N. Zhuravlev
2009, The Auk (126) 784-798
Philopatry has long been assumed to structure populations of waterfowl and other species of birds genetically, especially via maternally transmitted mitochondrial DNA (mtDNA), yet other migratory behaviors and nesting ecology (use of ground vs. cavity sites) may also contribute to population genetic structure. We investigated the effects of migration and...
A one-dimensional heat-transport model for conduit flow in karst aquifers
Andrew J. Long, P.C. Gilcrease
2009, Journal of Hydrology (378) 230-239
A one-dimensional heat-transport model for conduit flow in karst aquifers is presented as an alternative to two or three-dimensional distributed-parameter models, which are data intensive and require knowledge of conduit locations. This model can be applied for cases where water temperature in a well or spring receives all or part...
Process recognition in multi-element soil and stream-sediment geochemical data
E.C. Grunsky, L.J. Drew, D. M. Sutphin
2009, Applied Geochemistry (24) 1602-1616
Stream-sediment and soil geochemical data from the Upper and Lower Coastal Plains of South Carolina (USA) were studied to determine relationships between soils and stream sediments. From multi-element associations, characteristic compositions were determined for both media. Primary associations of elements reflect mineralogy, including heavy minerals, carbonates and clays, and the...
Characterizing canopy biochemistry from imaging spectroscopy and its application to ecosystem studies
R.F. Kokaly, Gregory P. Asner, S.V. Ollinger, M.E. Martin, C.A. Wessman
2009, Remote Sensing of Environment (113)
For two decades, remotely sensed data from imaging spectrometers have been used to estimate non-pigment biochemical constituents of vegetation, including water, nitrogen, cellulose, and lignin. This interest has been motivated by the important role that these substances play in physiological processes such as photosynthesis, their relationships with ecosystem processes such...
Thermal characteristics of amphibian microhabitats in a fire-disturbed landscape
B. R. Hossack, L.A. Eby, C.G. Guscio, P.S. Corn
2009, Forest Ecology and Management (258) 1414-1421
Disturbance has long been a central issue in amphibian conservation, often regarding negative effects of logging or other forest management activities, but some amphibians seem to prefer disturbed habitats. After documenting increased use of recently burned forests by boreal toads (Bufo boreas), we hypothesized that burned habitats provided improved thermal...
