Clay-mineral suites, sources, and inferred dispersal routes: Southern California continental shelf
J.R. Hein, J.S. Dowling, A. Schuetze, H.J. Lee
2003, Marine Environmental Research (56) 79-102
Clay mineralogy is useful in determining the distribution, sources, and dispersal routes of fine-grained sediments. In addition, clay minerals, especially smectite, may control the degree to which contaminants are adsorbed by the sediment. We analyzed 250 shelf sediment samples, 24 river-suspended-sediment samples, and 12 river-bed samples for clay-mineral contents in...
Application of a multipurpose unequal probability stream survey in the Mid-Atlantic Coastal Plain
S.W. Ator, A.R. Olsen, A.M. Pitchford, J. M. Denver
2003, Journal of the American Water Resources Association (39) 873-885
A stratified, spatially balanced sample with unequal probability selection was used to design a multipurpose survey of headwater streams in the Mid-Atlantic Coastal Plain. Objectives for the survey include unbiased estimates of regional stream conditions, and adequate coverage of unusual but significant environmental settings to support empirical modeling of the...
The influence of gender on the relationship between wildlife value orientations, beliefs, and the acceptability of lethal deer control in Cuyahoga Valley National Park
E.M. Dougherty, D.C. Fulton, D.H. Anderson
2003, Society and Natural Resources (16) 603-623
This study examines how wildlife value orientations, attitudes, and gender influence acceptance of lethal actions to control deer in Cuyahoga Valley National Park in Ohio. Data were collected from female and male residents (n = 659) in a nine-county area, the primary service area of the park. Females and males...
Some observations on colocated and closely spaced strong ground-motion records of the 1999 Chi-Chi, Taiwan, earthquake
G.-Q. Wang, D.M. Boore, H. Igel, X.-Y. Zhou
2003, Bulletin of the Seismological Society of America (93) 674-693
The digital accelerograph network installed in Taiwan produced a rich set of records from the 20 September 1999 Chi-Chi, Taiwan earthquake (Mw 7.6). Teledyne Geotech model A-800 and A-900A* digital accelerographs were colocated at 22 stations that recorded this event. Comparisons of the amplitudes, frequency content, and baseline offsets show...
A Visual Basic program to classify sediments based on gravel-sand-silt-clay ratios
L.J. Poppe, A.H. Eliason, M. E. Hastings
2003, Computers & Geosciences (29) 805-809
Nomenclature describing size distributions is important to geologists because grain size is the most basic attribute of sediments. Traditionally, geologists have divided sediments into four size fractions that include gravel, sand, silt, and clay, and classified these sediments based on ratios of the various proportions of the fractions. Definitions of...
Development of a multimetric index for assessing the biological condition of the Ohio River
E.B. Emery, T.P. Simon, F.H. McCormick, P. L. Angermeier, J.E. Deshon, C.O. Yoder, R.E. Sanders, W.D. Pearson, G.D. Hickman, R.J. Reash, J.A. Thomas
2003, Transactions of the American Fisheries Society (132) 791-808
The use of fish communities to assess environmental quality is common for streams, but a standard methodology for large rivers is as yet largely undeveloped. We developed an index to assess the condition of fish assemblages along 1,580 km of the Ohio River. Representative samples of fish assemblages were collected...
A delayed action oscillator shared by biennial, interannual, and decadal signals in the Pacific Basin
Warren B. White, Y.M. Tourre, M. Barlow, M. Dettinger
2003, Journal of Geophysical Research C: Oceans (108) 15-1
Biennial, interannual, and decadal signals in the Pacific basin are observed to share patterns and evolution in covarying sea surface temperature (SST), 18??C isotherm depth (Z18), zonal surface wind (ZSW), and wind stress curl (WSC) anomalies from 1955 to 1999. Each signal has warm SST anomalies propagating slowly eastward along...
Characterization and diagenesis of strong-acid carboxyl groups in humic substances
J.A. Leenheer, R.L. Wershaw, G.K. Brown, M.M. Reddy
2003, Applied Geochemistry (18) 471-482
A small fraction of carboxylic acid functional groups in humic substances are exceptionally acidic with pKa values as low as 0.5. A review of acid-group theory eliminated most models and explanations for these exceptionally acidic carboxyl groups. These acidic carboxyl groups in Suwannee River fulvic acid were enriched by a...
Simulating ground water-lake interactions: Approaches and insights
R. J. Hunt, H.M. Haitjema, J. T. Krohelski, D. T. Feinstein
2003, Ground Water (41) 227-237
Approaches for modeling lake-ground water interactions have evolved significantly from early simulations that used fixed lake stages specified as constant head to sophisticated LAK packages for MODFLOW. Although model input can be complex, the LAK package capabilities and output are superior to methods that rely on a fixed lake stage...
Isotopic composition of carbon dioxide from a boreal forest fire: Inferring carbon loss from measurements and modeling
E.A.G. Schuur, S.E. Trumbore, M.C. Mack, J.W. Harden
2003, Global Biogeochemical Cycles (17)
Fire is an important pathway for carbon (C) loss from boreal forest ecosystems and has a strong effect on ecosystem C balance. Fires can range widely in severity, defined as the amount of vegetation and forest floor consumed by fire, depending on local fuel and climatic conditions. Here we...
Shallow soil CO2 flow along the San Andreas and Calaveras Faults, California
J.L. Lewicki, William C. Evans, G.E. Hilley, M.L. Sorey, J.D. Rogie, S.L. Brantley
2003, Journal of Geophysical Research B: Solid Earth (108)
We evaluate a comprehensive soil CO2 survey along the San Andreas fault (SAF) in Parkfield, and the Calaveras fault (CF) in Hollister, California, in the context of spatial and temporal variability, origin, and transport of CO2 in fractured terrain. CO2 efflux was measured within grids with portable instrumentation and continously...
Slip distribution of the 1952 Tokachi-Oki earthquake (M 8.1) along the Kuril Trench deduced from tsunami waveform inversion
K. Hirata, E. Geist, K. Satake, Y. Tanioka, S. Yamaki
2003, Journal of Geophysical Research B: Solid Earth (108)
We inverted 13 tsunami waveforms recorded in Japan to estimate the slip distribution of the 1952 Tokachi-Oki earthquake (M 8.1), which occurred southeast off Hokkaido along the southern Kuril subduction zone. The previously estimated source area determined from tsunami travel times [Hatori, 1973] did not coincide with the observed aftershock...
Estimating population trends with a linear model
Jonathan Bart, Brian D. Collins, R. I. G. Morrison
2003, The Condor (105) 367-372
We describe a simple and robust method for estimating trends in population size. The method may be used with Breeding Bird Survey data, aerial surveys, point counts, or any other program of repeated surveys at permanent locations. Surveys need not be made at each location during each survey period. The...
Influence of transitional volcanic strata on lateral diversion at Yucca Mountain, Nevada
Lorraine E. Flint, Alan L. Flint, John S. Selker
2003, Water Resources Research (39) 4-1-4-17
Natural hydraulic barriers exist at Yucca Mountain, Nevada, a potential high‐level nuclear waste repository, that have been identified as possible lateral diversions for reducing deep percolation through the waste storage area. Historical development of the conceptual model of lateral diversion has been limited by available field data, but numerical investigations...
MODFLOW 2000 Head Uncertainty, a First-Order Second Moment Method
H.S. Glasgow, M.D. Fortney, J. Lee, A.J. Graettinger, H. W. Reeves
2003, Ground Water (41) 342-350
A computationally efficient method to estimate the variance and covariance in piezometric head results computed through MODFLOW 2000 using a first-order second moment (FOSM) approach is presented. This methodology employs a first-order Taylor series expansion to combine model sensitivity with uncertainty in geologic data. MODFLOW 2000 is used to calculate...
Inorganic nitrogen transformations in the bed of the Shingobee River, Minnesota: Integrating hydrologic and biological processes using sediment perfusion cores
R.W. Sheibley, J.H. Duff, A. P. Jackman, F.J. Triska
2003, Limnology and Oceanography (48) 1129-1140
Inorganic N transformations were examined in streambed sediments from the Shingobee River using sediment perfusion cores. The experimental design simulated groundwater-stream water mixing within sediment cores, which provided a well-defined one-dimensional representation of in situ hydrologic conditions. Two distinct hydrologic and chemical settings were preserved in the sediment cores: the...
Density of the continental roots: Compositional and thermal contributions
M.K. Kaban, P. Schwintzer, I.M. Artemieva, Walter D. Mooney
2003, Earth and Planetary Science Letters (209) 53-69
The origin and evolution of cratonic roots has been debated for many years. Precambrian cratons are underlain by cold lithospheric roots that are chemically depleted. Thermal and petrologic data indicate that Archean roots are colder and more chemically depleted than Proterozoic roots. This observation has led to the hypothesis that...
Volcano seismology
B. Chouet
2003, Pure and Applied Geophysics (160) 739-788
A fundamental goal of volcano seismology is to understand active magmatic systems, to characterize the configuration of such systems, and to determine the extent and evolution of source regions of magmatic energy. Such understanding is critical to our assessment of eruptive behavior and its hazardous impacts. With the emergence of...
Comparison of approaches for simulating reactive solute transport involving organic degradation reactions by multiple terminal electron acceptors
Gary P. Curtis
2003, Computers & Geosciences (29) 319-329
Reactive solute transport models are useful tools for analyzing complex geochemical behavior resulting from biodegradation of organic compounds by multiple terminal electron acceptors (TEAPs). The usual approach of simulating the reactions of multiple TEAPs by an irreversible Monod rate law was compared with simulations that assumed a partial local equilibrium...
Signatures of the seismic source in EMD-based characterization of the 1994 Northridge, California, earthquake recordings
R.R. Zhang, S. Ma, S. Hartzell
2003, Bulletin of the Seismological Society of America (93) 501-518
In this article we use empirical mode decomposition (EMD) to characterize the 1994 Northridge, California, earthquake records and investigate the signatures carried over from the source rupture process. Comparison of the current study results with existing source inverse solutions that use traditional data processing suggests that the EMD-based characterization contains...
Shallow-velocity models at the Kilauea Volcano, Hawaii, determined from array analyses of tremor wavefields
G. Saccorotti, B. Chouet, P. Dawson
2003, Geophysical Journal International (152) 633-648
The properties of the surface wavefield at Kilauea Volcano are analysed using data from small-aperture arrays of short-period seismometers deployed in and around the Kilauea caldera. Tremor recordings were obtained during two Japan-US cooperative experiments conducted in 1996 and 1997. The seismometers were deployed in three semi-circular arrays with apertures...
Optical dating of tufa via in situ aeolian sand grains: A case example from the Southern High Plains, USA
J. Rich, S. Stokes, W. Wood, R. Bailey
2003, Conference Paper, Quaternary Science Reviews
Precipitated carbonates (commonly termed tufas or travertines) maybe of considerable utility for palaeoenvironmental reconstruction. Their potential, however, for such reconstruction is commonly limited by difficulties associated with their absolute age control. Attempts to date such deposits via uranium series techniques have been complicated by their chemically open behaviour. Here we...
Mapping the spatial distribution and time evolution of snow water equivalent with passive microwave measurements
J. Guo, L. Tsang, E.G. Josberger, A.W. Wood, J.-N. Hwang, D.P. Lettenmaier
2003, IEEE Transactions on Geoscience and Remote Sensing (41) 612-621
This paper presents an algorithm that estimates the spatial distribution and temporal evolution of snow water equivalent and snow depth based on passive remote sensing measurements. It combines the inversion of passive microwave remote sensing measurements via dense media radiative transfer modeling results with snow accumulation and melt model predictions...
Interdecadal change in the deep Puget sound benthos
F.H. Nichols
2003, Hydrobiologia (493) 95-114
Data from quantitative samples of the benthos at a 200-m site in central Puget Sound, collected twice yearly in most years between 1963 and 1992, were evaluated to determine the extent to which species composition in a continental-shelf depth community exhibits long-term persistence. Study results showed that the most abundant...
Serpentinization of abyssal peridotites from the MARK area, Mid-Atlantic Ridge: Sulfur geochemistry and reaction modeling
J.C. Alt, Wayne C. Shanks III
2003, Geochimica et Cosmochimica Acta (67) 641-653
The opaque mineralogy and the contents and isotope compositions of sulfur in serpentinized peridotites from the MARK (Mid-Atlantic Ridge, Kane Fracture Zone) area were examined to understand the conditions of serpentinization and evaluate this process as a sink for seawater sulfur. The serpentinites contain a sulfur-rich secondary mineral assemblage and...
