Generating an image of dispersive energy by frequency decomposition and slant stacking
J. Xia, Y. Xu, R. D. Miller
2007, Pure and Applied Geophysics (164) 941-956
We present a new algorithm for calculating an image of dispersive energy in the frequency-velocity (f-v) domain. The frequency decomposition is first applied to a shot gather in the offset-time domain to stretch impulsive data into pseudo-vibroseis data or frequency-swept data. Because there is a deterministic relationship between frequency and...
Bedrock aquifers and population growth in the Denver Basin, Colorado, USA
J.E. Moore, R.G. Raynolds, M. Dechesne
2007, Episodes (30) 115-118
The Denver Basin bedrock aquifer system consists of Tertiary and Cretaceous age sedimentary rocks known as the Dawson, Denver, Arapahoe and Laramie-Fox Hills aquifers. The number of bedrock wells has increased from 12,000 in 1985 to over 33,700 in 2001 and the withdrawal of groundwater has caused water level declines...
A simple daily soil-water balance model for estimating the spatial and temporal distribution of groundwater recharge in temperate humid areas
W. R. Dripps, K. R. Bradbury
2007, Hydrogeology Journal (15) 433-444
Quantifying the spatial and temporal distribution of natural groundwater recharge is usually a prerequisite for effective groundwater modeling and management. As flow models become increasingly utilized for management decisions, there is an increased need for simple, practical methods to delineate recharge zones and quantify recharge rates. Existing models for estimating...
Influence of tectonic folding on rockfall susceptibility, American Fork Canyon, Utah, USA
J. A. Coe, E. L. Harp
2007, Natural Hazards and Earth System Sciences (7) 1-14
We examine rockfall susceptibility of folded strata in the Sevier fold-thrust belt exposed in American Fork Canyon in north-central Utah. Large-scale geologic mapping, talus production data, rock-mass-quality measurements, and historical rockfall data indicate that rockfall susceptibility is correlated with limb dip and curvature of the folded, cliff-forming Mississippian limestones. On...
Late Quaternary stratigraphy and luminescence geochronology of the northeastern Mojave Desert
S. A. Mahan, D. M. Miller, C.M. Menges, J. C. Yount
2007, Quaternary International (166) 61-78
The chronology of the Holocene and late Pleistocene deposits of the northeastern Mojave Desert have been largely obtained using radiocarbon ages. Our study refines and extends this framework using optically stimulated luminescence (OSL) to date deposits from Valjean Valley, Silurian Lake Playa, Red Pass, and California Valley. Of particular interest...
Habitat characteristics of adult frosted elfins (Callophrys irus) in sandplain communities of southeastern Massachusetts, USA
G. Albanese, P.D. Vickery, P.R. Sievert
2007, Biological Conservation (136) 53-64
Changes to land use and disturbance frequency threaten disturbance-dependent Lepidoptera within sandplain habitats of the northeastern United States. The frosted elfin (Callophrys irus) is a rare and declining monophagous butterfly that is found in xeric open habitats maintained by disturbance. We surveyed potential habitat for adult frosted elfins at four...
Propagation of the Hawaiian-Emperor volcano chain by Pacific plate cooling stress
W.D. Stuart, G.R. Foulger, M. Barall
2007, Special Paper of the Geological Society of America (430) 497-506
The lithosphere crack model, the main alternative to the mantle plume model for age-progressive magma emplacement along the Hawaiian-Emperor volcano chain, requires the maximum horizontal tensile stress to be normal to the volcano chain. However, published stress fields calculated from Pacific lithosphere tractions and body forces...
The restricted gemuk group: A triassic to lower cretaceous succession in southwestern Alaska
Marti L. Miller, D. C. Bradley, T. K. Bundtzen, R. B. Blodgett, E.A. Pessagno Jr., R. D. Tucker, A. G. Harris
2007, Special Paper of the Geological Society of America 273-305
New data from an Upper Triassic to Lower Cretaceous deep marine succession-the herein reinstated and restricted Gemuk Group-provide a vital piece of the puzzle for unraveling southwestern Alaska's tectonic history. First defined by Cady et al. in 1955, the Gemuk Group soon became a regional catchall unit that ended up...
Ground-penetrating radar: A tool for monitoring bridge scour
N.L. Anderson, A.M. Ismael, T. Thitimakorn
2007, Environmental & Engineering Geoscience (13) 1-10
Ground-penetrating radar (GPR) data were acquired across shallow streams and/or drainage ditches at 10 bridge sites in Missouri by maneuvering the antennae across the surface of the water and riverbank from the bridge deck, manually or by boat. The acquired two-dimensional and three-dimensional data sets accurately image the channel bottom,...
Modelingevapotranspirationina sub-tropical climate
M.R. Savabi, T.A. Cochrane, E. German, C. Ikiz, N. Cockshutt
2007, Journal of Environmental Hydrology (15) 1-15
Evapotranspiration (ET) loss is estimated at about 80-85% of annual precipitation in South Florida. Accurate prediction of ET is important during and beyond the implementation of the Comprehensive Everglades Restoration Plan (CERP). In the USDA's Everglades Agro-Hydrology Model (EAHM) the soil water intake is linked with the soil water redistribution,...
Surface drifter derived circulation in the northern and middle Adriatic Sea: Response to wind regime and season
L. Ursella, P.-M. Poulain, R. P. Signell
2007, Journal of Geophysical Research C: Oceans (112)
More than 120 satellite-tracked drifters were deployed in the northern and middle Adriatic (NMA) Sea between September 2002 and November 2003, with the purpose of studying the surface circulation at mesoscale to seasonal scale in relation to wind forcing, river runoff, and bottom topography. Pseudo-Eulerian and Lagrangian statistics were calculated...
Blooms of the toxic dinoflagellate Alexandrium fundyense in the western Gulf of Maine in 1993 and 1994: A comparative modeling study
C.A. Stock, D.J. McGillicuddy Jr., D.M. Anderson, A.R. Solow, R. P. Signell
2007, Continental Shelf Research (27) 2486-2512
Blooms of the toxic dinoflagellate Alexandrium fundyense commonly occur in the western Gulf of Maine but the amount of toxin observed in coastal shellfish is highly variable. In this study, a coupled physical-biological model is used to investigate the dynamics underlying the observed A. fundyense abundance and shellfish toxicity in...
Prioritizing bottomland hardwood forest sites for protection and augmentation
J. Carter, J. Biagas
2007, Natural Areas Journal (27) 72-82
Bottomland hardwood forest has been greatly diminished by conversion to agriculture. Less than 25% of the pre-Columbian bottomland hardwood forests remain in the southeastern United States. Because of the valuable ecological and hydrological functions performed by these forests, their conservation and restoration has been a high priority. Part of these...
The role of historical fire disturbance in the carbon dynamics of the pan-boreal region: A process-based analysis
M. S. Balshi, A. D. McGuire, Q. Zhuang, J. Melillo, D. W. Kicklighter, E. Kasischke, C. Wirth, M. Flannigan, J. Harden, Joy S. Clein, T.J. Burnside, J. McAllister, W.A. Kurz, M. Apps, A. Shvidenko
2007, Journal of Geophysical Research G: Biogeosciences (112)
[1] Wildfire is a common occurrence in ecosystems of northern high latitudes, and changes in the fire regime of this region have consequences for carbon feedbacks to the climate system. To improve our understanding of how wildfire influences carbon dynamics of this region, we used...
A rangewide population genetic study of trumpeter swans
S.J. Oyler-McCance, F.A. Ransler, L.K. Berkman, T.W. Quinn
2007, Conservation Genetics (8) 1339-1353
For management purposes, the range of naturally occurring trumpeter swans (Cygnus buccinator) has been divided into two populations, the Pacific Coast Population (PP) and the Rocky Mountain Population (RMP). Little is known about the distribution of genetic variation across the species' range despite increasing pressure to make difficult management decisions...
Use of streamflow data to estimate base flowground-water recharge for Wisconsin
W.A. Gebert, M.J. Radloff, E.J. Considine, J.L. Kennedy
2007, Journal of the American Water Resources Association (43) 220-236
The average annual base flow/recharge was determined for streamflow-gaging stations throughout Wisconsin by base-flow separation. A map of the State was prepared that shows the average annual base flow for the period 1970-99 for watersheds at 118 gaging stations. Trend analysis was performed on 22 of the 118 streamflow-gaging stations...
Chinook salmon use of spawning patches: Relative roles of habitat quality, size, and connectivity
D.J. Isaak, R.F. Thurow, B.E. Rieman, J. B. Dunham
2007, Ecological Applications (17) 352-364
Declines in many native fish populations have led to reassessments of management goals and shifted priorities from consumptive uses to species preservation. As management has shifted, relevant environmental characteristics have evolved from traditional metrics that described local habitat quality to characterizations of habitat size and connectivity. Despite the implications this...
Heat, chloride, and specific conductance as ground water tracers near streams
M.H. Cox, G.W. Su, J. Constantz
2007, Ground Water (45) 187-195
Commonly measured water quality parameters were compared to heat as tracers of stream water exchange with ground water. Temperature, specific conductance, and chloride were sampled at various frequencies in the stream and adjacent wells over a 2-year period. Strong seasonal variations in stream water...
Earthquake-by-earthquake fold growth above the Puente Hills blind thrust fault, Los Angeles, California: Implications for fold kinematics and seismic hazard
L.A. Leon, S.A. Christofferson, J.F. Dolan, J.H. Shaw, T. L. Pratt
2007, Journal of Geophysical Research B: Solid Earth (112)
Boreholes and high-resolution seismic reflection data collected across the forelimb growth triangle above the central segment of the Puente Hills thrust fault (PHT) beneath Los Angeles, California, provide a detailed record of incremental fold growth during large earthquakes on this major blind thrust fault. These data document fold growth within...
Remote sensing and GIS technology in the Global Land Ice Measurements from Space (GLIMS) Project
B. Raup, Andreas Kaab, J.S. Kargel, M.P. Bishop, G. Hamilton, E. Lee, F. Paul, F. Rau, D. Soltesz, S.J.S. Khalsa, M. Beedle, C. Helm
2007, Computers & Geosciences (33) 104-125
Global Land Ice Measurements from Space (GLIMS) is an international consortium established to acquire satellite images of the world's glaciers, analyze them for glacier extent and changes, and to assess these change data in terms of forcings. The consortium is organized into a system of Regional Centers, each of which...
Distribution, habitat, size, and color pattern of Cnemidophorus lemniscatus (Sauria: Teiidae) on Cayo Cochino Pequeño, Honduras
Chad E. Montgomery, Robert N. Reed, Hayley J. Shaw, Scott M. Boback, James M. Walker
2007, Southwestern Naturalist (52) 38-45
Cayo Cochino Pequeño is a 0.64-km2 Caribbean island in the Cayos Cochinos archipelago, Department of Islas de la Bahía, Honduras. One published report noted the presence of the rainbow whiptail (Cnemidophorus lemniscatus) on Cayo Cochino Pequeño, but nothing is known about the biology of this insular population. During a part of...
Online catalog of world-wide test sites for the post-launch characterization and calibration of optical sensors
G. Chander, J.B. Christopherson, G. L. Stensaas, P.M. Teillet
2007, Conference Paper, International Astronautical Federation - 58th International Astronautical Congress 2007
In an era when the number of Earth-observing satellites is rapidly growing and measurements from these sensors are used to answer increasingly urgent global issues, it is imperative that scientists and decision-makers rely on the accuracy of Earth-observing data products. The characterization and calibration of these sensors are vital to...
Monitoring and modeling ice-rock avalanches from ice-capped volcanoes: A case study of frequent large avalanches on Iliamna Volcano, Alaska
C. Huggel, J. Caplan-Auerbach, C. F. Waythomas, R.L. Wessels
2007, Journal of Volcanology and Geothermal Research (168) 114-136
Iliamna is an andesitic stratovolcano of the Aleutian arc with regular gas and steam emissions and mantled by several large glaciers. Iliamna Volcano exhibits an unusual combination of frequent and large ice-rock avalanches in the order of 1 ?? 106??m3 to 3 ?? 107??m3 with recent return periods of 2-4??years....
Geochemical and geophysical examination of submarine groundwater discharge and associated nutrient loading estimates into Lynch Cove, Hood Canal, WA
P.W. Swarzenski, F. W. Simonds, A.J. Paulson, S. Kruse, C. Reich
2007, Environmental Science & Technology (41) 7022-7029
Geochemical tracer data (i.e., 222Rn and four naturally occurring Ra isotopes), electromagnetic (EM) seepage meter results, and high-resolution, stationary electrical resistivity images were used to examine the bi-directional (i.e., submarine groundwater discharge and recharge) exchange of a coastal aquifer with seawater. Our study site for these experiments was Lynch Cove,...
Near-fault peak ground velocity from earthquake and laboratory data
Art McGarr, Joe B. Fletcher
2007, Bulletin of the Seismological Society of America (97) 1502-1510
We test the hypothesis that peak ground velocity (PGV) has an upper bound independent of earthquake magnitude and that this bound is controlled primarily by the strength of the seismogenic crust. The highest PGVs, ranging up to several meters per second, have been measured at sites within a few kilometers...
