Oil and gas reserve growth-a model for the Volga-Ural Province, Russia
M.K. Verma, G. F. Ulmishek, A.P. Gilbershtein
2000, Conference Paper, SPE/AAPG Western Regional Meetings
An understanding of reserve growth in known oil and gas fields has become a critical component of energy resource analysis. Significant statistical studies of reserve growth have been published in the U.S., whereas little information is available on other regions of the world. It may be expected that in many...
A method for producing digital probabilistic seismic landslide hazard maps
R.W. Jibson, E. L. Harp, J. A. Michael
2000, Engineering Geology (58) 271-289
The 1994 Northridge, California, earthquake is the first earthquake for which we have all of the data sets needed to conduct a rigorous regional analysis of seismic slope instability. These data sets include: (1) a comprehensive inventory of triggered landslides, (2) about 200 strong-motion records of the mainshock, (3) 1:24...
The effects of gap size and disturbance type on invasion of wet pine savanna by cogongrass, Imperata cylindrica (Poaceae)
S.E. King, J.B. Grace
2000, American Journal of Botany (87) 1279-1286
Cogongrass is a nonindigenous species perceived to threaten native communities of the southeastern United States through modification of species composition and alteration of community processes. To examine how gap size and disturbance type influence the invasion of wet pine savannas by cogongrass, we performed three field experiments to evaluate the...
Acoustic properties of a crack containing magmatic or hydrothermal fluids
Hiroyuki Kumagai, B. A. Chouet
2000, Journal of Geophysical Research B: Solid Earth (105) 25493-25512
We estimate the acoustic properties of a crack containing magmatic or hydrothermal fluids to quantify the source properties of long-period (LP) events observed in volcanic areas assuming that a crack-like structure is the source of LP events. The tails of synthetic waveforms obtained from a model of a fluid-driven crack...
Orbital and suborbital variability in North Atlantic bottom water temperature obtained from deep-sea ostracod Mg/Ca ratios
T. M. Cronin, G. S. Dwyer, P.A. Baker, J. Rodriguez-Lazaro, D.M. DeMartino
2000, Palaeogeography, Palaeoclimatology, Palaeoecology (162) 45-57
Magnesium/calcium (Mg/Ca) ratios were measured in the deep-sea ostracod (Crustacea) genus Krithe from Chain core 82-24-4PC from the western mid-Atlantic Ridge (3427 m) in order to estimate ocean circulation and bottom water temperature (BWT) variability over the past 200,000 years. Mg/Ca ratios have been used as a paleothermometer because the ratios...
206Pb-230Th-234U-238U and 207Pb-235U geochronology of Quaternary opal, Yucca Mountain, Nevada
Leonid A. Neymark, Yuri V. Amelin, James B. Paces
2000, Geochimica et Cosmochimica Acta (64) 2913-2928
U–Th–Pb isotopic systems have been studied in submillimeter-thick outermost layers of Quaternary opal occurring in calcite–silica fracture and cavity coatings within Tertiary tuffs at Yucca Mountain, Nevada, USA. These coatings preserve a record of paleohydrologic conditions at this site, which is being evaluated as a potential high-level nuclear waste repository....
Exposure age and erosional history of an upland planation surface in the US Atlantic Piedmont
S.D. Stanford, M.A. Seidl, G.M. Ashley
2000, Earth Surface Processes and Landforms (25) 939-950
The upland planation surface in the Piedmont of central New Jersey consists of summit flats, as much as 130 km2 in area, that truncate bedding and structure in diabase, basalt, sandstone, mudstone and gneiss. These flats define a low-relief regional surface that corresponds in elevation to residual hills in the...
Sexing adult black-legged kittiwakes by DNA, behavior, and morphology
P.G.R. Jodice, Richard B. Lanctot, V.A. Gill, D.D. Roby, Scott A. Hatch
2000, Waterbirds (23) 405-415
We sexed adult Black-legged Kittiwakes (Rissa tridactyla) using DNA-based genetic techniques, behavior and morphology and compared results from these techniques. Genetic and morphology data were collected on 605 breeding kittiwakes and sex-specific behaviors were recorded for a sub-sample of 285 of these individuals. We compared sex classification based on both...
Evaluation of ground-penetrating radar to detect free-phase hydrocarbons in fractured rocks: Results of numerical modeling and physical experiments
J.W. Lane Jr., M. L. Buursink, F.P. Haeni, R.J. Versteeg
2000, Ground Water (38) 929-938
The suitability of common-offset ground-penetrating radar (GPR) to detect free-phase hydrocarbons in bedrock fractures was evaluated using numerical modeling and physical experiments. The results of one- and two-dimensional numerical modeling at 100 megahertz indicate that GPR reflection amplitudes are relatively insensitive to fracture apertures ranging from 1 to 4 mm....
Magma mixing, recharge and eruption histories recorded in plagioclase phenocrysts from El Chichón Volcano, Mexico
F. J. Tepley III, J.P. Davidson, R.I. Tilling, Joseph G. Arth
2000, Journal of Petrology (41) 1397-1411
Consistent core-to-rim decreases of 87Sr/86Sr ratios and coincident increases in Sr concentrations in plagioclase phenocrysts of varying size (∼1 cm to 2 mm) are reported from samples of the 1982 and pre-1982 (∼200 ka) eruptions of El Chichón Volcano. Maximum 87Sr/86Sr ratios of ∼0·7054, significantly higher than the whole-rock isotopic ratios...
Alachlor transformation patterns in aquatic field mesocosms under variable oxygen and nutrient conditions
D.W. Graham, M.K. Miley, F. Denoyelles, Val H. Smith, E.M. Thurman, R. Carter
2000, Water Research (34) 4054-4062
Alachlor is one of the most commonly used herbicides in both Europe and North America. Because of its toxic properties, its fate and attenuation in natural waters is practically important. This paper assesses factors that affect alachlor decay rate in aquatic systems using field-scale experimental units. In particular, we used...
On the modified Mercalli intensities and magnitudes of the 1811-1812 New Madrid earthquakes
S. E. Hough, J.G. Armbruster, L. Seeber, J.F. Hough
2000, Journal of Geophysical Research B: Solid Earth (105) 23839-23864
We reexamine original felt reports from the 1811–1812 New Madrid earthquakes and determine revised isoseismal maps for the three principal mainshocks. In many cases we interpret lower values than those assigned by earlier studies. In some cases the revisions result from an interpretation of original felt reports with an appreciation...
Pore fluid pressure, apparent friction, and Coulomb failure
N.M. Beeler, R.W. Simpson, S.H. Hickman, D.A. Lockner
2000, Journal of Geophysical Research B: Solid Earth (105) 25533-25542
Many recent studies of stress-triggered seismicity rely on a fault failure model with a single free parameter, the apparent coefficient of friction, presumed to be a material constant with possible values 0 ≤ μ′ ≤ 1. These studies may present a misleading view of fault strength and the role of...
Viscoelastic-coupling model for the earthquake cycle driven from below
J.C. Savage
2000, Journal of Geophysical Research B: Solid Earth (105) 25525-25532
In a linear system the earthquake cycle can be represented as the sum of a solution which reproduces the earthquake cycle itself (viscoelastic-coupling model) and a solution that provides the driving force. We consider two cases, one in which the earthquake cycle is driven by stresses transmitted along the schizosphere...
Bedrock knobs, San Francisco Bay: Do navigation hazards outweigh other environment problems?
Paul R. Carlson, John L. Chin, Florence L. Wong
2000, Environmental & Engineering Geoscience (6) 41-55
Three bedrock knobs (Arch, Harding, and Shag rocks) rise above the unconsolidated sediment of central San Francisco Bay to a water depth of less than -12 m (<-39.4 ft MLLW). These rocks are within the westbound vessel traffic area, and the northernmost, Harding Rock, is approximately 300 m (984 ft)...
Preface paper to the Semi-Arid Land-Surface-Atmosphere (SALSA) Program special issue
D.C. Goodrich, A. Chehbouni, B. Goff, B. MacNish, T. Maddock, S. Moran, W.J. Shuttleworth, D. G. Williams, C. Watts, L.H. Hipps, D.I. Cooper, J. Schieldge, Y.H. Kerr, H. Arias, M. Kirkland, R. Carlos, P. Cayrol, W. Kepner, B. Jones, R. Avissar, A. Begue, J.-M. Bonnefond, G. Boulet, B. Branan, J.P. Brunel, L.C. Chen, T. Clarke, M.R. Davis, H. DeBruin, G. Dedieu, E. Elguero, W.E. Eichinger, J. Everitt, J. Garatuza-Payan, V.L. Gempko, H. Gupta, C. Harlow, O. Hartogensis, M. Helfert, C. Holifield, D. Hymer, A. Kahle, T. Keefer, S. Krishnamoorthy, J.-P. Lhomme, J.-P. Lagouarde, Seen D. Lo, D. Luquet, R. Marsett, B. Monteny, W. Ni, Y. Nouvellon, R. Pinker, C. Peters, D. Pool, J. Qi, S. Rambal, J. Rodriguez, F. Santiago, E. Sano, S.M. Schaeffer, M. Schulte, R. Scott, X. Shao, K.A. Snyder, S. Sorooshian, C.L. Unkrich, M. Whitaker, I. Yucel
2000, Conference Paper, Agricultural and Forest Meteorology
The Semi-Arid Land-Surface-Atmosphere Program (SALSA) is a multi-agency, multi-national research effort that seeks to evaluate the consequences of natural and human-induced environmental change in semi-arid regions. The ultimate goal of SALSA is to advance scientific understanding of the semi-arid portion of the hydrosphere-biosphere interface in order to provide reliable information...
Reproductive ecology of the Maui Parrotbill
John C. Simon, Thane K. Pratt, Kim E. Berlin, James R. Kowalsky
2000, The Wilson Bulletin (112) 482-490
The endangered Maui Parrotbill (Pseudonestor xanthophrys) is an excavating, insectivorous Hawaiian honeycreeper endemic to the high elevation rain forests of east Maui, Hawaii. From March 1994 to June 1997, we studied various aspects of their breeding ecology. We color-banded 18 individuals, located and monitored 9 active nests, and...
Testing a full‐range soil‐water retention function in modeling water potential and temperature
Brian J. Andraski, Elizabeth A. Jacobson
2000, Water Resources Research (36) 3081-3089
Recent work has emphasized development of full‐range water‐retention functions that are applicable under both wet and dry soil conditions, but evaluation of such functions in numerical modeling has been limited. Here we show that simulations using the Rossi‐Nimmo (RN) full‐range function compared favorably with those using the common Brooks‐Corey function...
Nano-metrology and terrain modelling - convergent practice in surface characterisation
R.J. Pike
2000, Tribology International (33) 593-600
The quantification of magnetic-tape and disk topography has a macro-scale counterpart in the Earth sciences - terrain modelling, the numerical representation of relief and pattern of the ground surface. The two practices arose independently and continue to function separately. This methodological paper introduces terrain modelling, discusses its similarities to and...
Seasonal estimates of riparian evapotranspiration using remote and in situ measurements
D.C. Goodrich, R. Scott, J. Qi, B. Goff, C.L. Unkrich, M. S. Moran, D. Williams, S. Schaeffer, K. Snyder, R. MacNish, T. Maddock, D. Pool, A. Chehbouni, D.I. Cooper, W.E. Eichinger, W.J. Shuttleworth, Y. Kerr, R. Marsett, W. Ni
2000, Conference Paper, Agricultural and Forest Meteorology
In many semi-arid basins during extended periods when surface snowmelt or storm runoff is absent, groundwater constitutes the primary water source for human habitation, agriculture and riparian ecosystems. Utilizing regional groundwater models in the management of these water resources requires accurate estimates of basin boundary conditions. A critical groundwater boundary...
Re-Os isotopic systematics of primitive lavas from the Lassen region of the Cascade arc, California
L. E. Borg, A.D. Brandon, M.A. Clynne, R.J. Walker
2000, Earth and Planetary Science Letters (177) 301-317
Rhenium-osmium isotopic systematics of primitive calc-alkaline lavas from the Lassen region appear to be controlled by mantle wedge processes. Lavas with a large proportion of slab component have relatively low Re and Os abundances, and have radiogenic Os and mid ocean ridge basalt-like Sr and Pb isotopic compositions. Lavas with...
Strain accumulation along the Cascadia subduction zone
M.H. Murray, M. Lisowski
2000, Geophysical Research Letters (27) 3631-3634
We combine triangulation, trilateration, and GPS observations to determine horizontal strain rates along the Cascadia subduction zone from Cape Mendocino to the Strait of Juan de Fuca. Shear-strain rates are significantly greater than zero (95% confidence) in all forearc regions (26-167 nanoradians/yr), and are not significant in the arc and...
Updated population metadata for United States historical climatology network stations
T.W. Owen, K. P. Gallo
2000, Journal of Climate (13) 4028-4033
The United States Historical Climatology Network (HCN) serial temperature dataset is comprised of 1221 high-quality, long-term climate observing stations. The HCN dataset is available in several versions, one of which includes population-based temperature modifications to adjust urban temperatures for the "heat-island" effect. Unfortunately, the decennial population metadata file is not...
Variability of site response in Seattle, Washington
S. Hartzell, D. Carver, E. Cranswick, A. Frankel
2000, Bulletin of the Seismological Society of America (90) 1237-1250
Ground motion from local earthquakes and the SHIPS (Seismic Hazards Investigation in Puget Sound) experiment is used to estimate site amplification factors in Seattle. Earthquake and SHIPS records are analyzed by two methods: (1) spectral ratios relative to a nearby site on Tertiary sandstone, and (2) a source/site spectral inversion...
Legacy of the California Gold Rush: Environmental geochemistry of arsenic in the southern Mother Lode Gold District
K. S. Savage, D.K. Bird, R. P. Ashley
2000, International Geology Review (42) 385-415
Gold mining activity in the Sierra Nevada foothills, both recently and during the California Gold Rush, has exposed arsenic-rich pyritic rocks to weathering and erosion. This study describes arsenic concentration and speciation in three hydrogeologic settings in the southern Mother Lode Gold District: mineralized outcrops and mine waste rock (overburden);...
