Orientation-independent measures of ground motion
D.M. Boore, Jennie Watson-Lamprey, N. A. Abrahamson
2006, Bulletin of the Seismological Society of America (96) 1502-1511
The geometric mean of the response spectra for two orthogonal horizontal components of motion, commonly used as the response variable in predictions of strong ground motion, depends on the orientation of the sensors as installed in the field. This means that the measure of ground-motion intensity could differ for the...
Instantaneous unit hydrograph evaluation for rainfall-runoff modeling of small watersheds in North and South Central Texas
T.G. Cleveland, X. He, W.H. Asquith, X. Fang, D.B. Thompson
2006, Journal of Irrigation and Drainage Engineering (132) 479-485
Data from over 1,600 storms at 91 stations in Texas are analyzed to evaluate an instantaneous unit hydrograph (IUH) model for rainfall-runoff models. The model is fit to observed data using two different merit functions: a sum of squared errors function, and an absolute error at the peak discharge time...
A multivariate model of plant species richness in forested systems: Old-growth montane forests with a long history of fire
D.C. Laughlin, J.B. Grace
2006, Oikos (114) 60-70
Recently, efforts to develop multivariate models of plant species richness have been extended to include systems where trees play important roles as overstory elements mediating the influences of environment and disturbance on understory richness. We used structural equation modeling to examine the relationship of understory vascular plant species richness to...
Sensor web enables rapid response to volcanic activity
Ashley G. Davies, Steve Chien, Robert Wright, Asta Mikijus, Philip R. Kyle, Matt Welsh, Jeffrey B. Johnson, Daniel Tran, Steven R. Schaffer, Robert Sherwood
2006, Eos, Transactions, American Geophysical Union (87) 2-4
Rapid response to the onset of volcanic activity allows for the early assessment of hazard and risk [Tilling, 1989]. Data from remote volcanoes and volcanoes in countries with poor communication infrastructure can only be obtained via remote sensing [Harris et al., 2000]. By linking notifications of activity from ground-based and...
Geochemistry of low-temperature springs northwest of Yellowstone caldera: Seeking the link between seismicity, deformation, and fluid flow
William C. Evans, Deborah Bergfeld, Matthias C. van Soest, Mark Huebner, John Fitzpatrick, Kinga M. Revesz
2006, Journal of Volcanology and Geothermal Research (154) 169-180
A comprehensive geochemical survey of springs outside the northwest margin of the Yellowstone caldera was undertaken in 2003 and 2004. This survey was designed to detect: (1) active leakage from a huge reservoir of CO2 gas recently postulated to extend from beneath the caldera into this area; and (2) lingering evidence...
A revised lithostratigraphic framework for the southern Yucca Mountain area, Nye County, Nevada
R.W. Spengler, F. M. Byers, R. P. Dickerson
2006, Conference Paper, Proceedings of the 11th International High Level Radioactive Waste Management Conference, IHLRWM
An informal, revised lithostratigraphic framework for the southern Yucca Mountain area, Nevada has been developed to accommodate new information derived from subsurface investigations of the Nye County Early Warning Drilling Program. Lithologies penetrated by recently drilled boreholes at locations between Stagecoach Road and Highway 95 in southern Nye County include...
Fluorspar
M. Miller
2006, Mining Engineering (58) 30-31
In 2005, most of the fourspar consumed in the United States was imported or purchased from the US National Defense Stockpile (NDS). For the year, the estimated annual production of fluorosilicic acid was 49 kt or about 86 kt of 92% flourspar equivalent. Prices increased due to reduced exports from...
Fire decreases arthropod abundance but increases diversity: Early and late season prescribed fire effects in a Sierra Nevada mixed-conifer forest
Scott Ferrenberg, Dylan W. Schwilk, Eric E. Knapp, Eric Groth, Jon E. Keeley
2006, Fire Ecology (2) 79-102
Prior to fire suppression in the 20th century, the mixed-conifer forests of the Sierra Nevada, California, U.S.A., historically burned in frequent fires that typically occurred during the late summer and early fall. Fire managers have been attempting to restore natural ecosystem processes through prescription burning, and have often favored burning...
Regional processes in mangrove ecosystems: Spatial scaling relationships, biomass, and turnover rates following catastrophic disturbance
G.A. Ward, T. J. Smith III, K.R.T. Whelan, T.W. Doyle
2006, Hydrobiologia (569) 517-527
Physiological processes and local-scale structural dynamics of mangroves are relatively well studied. Regional-scale processes, however, are not as well understood. Here we provide long-term data on trends in structure and forest turnover at a large scale, following hurricane damage in mangrove ecosystems of South Florida, U.S.A. Twelve mangrove vegetation plots...
Canopy reflectance related to marsh dieback onset and progression in Coastal Louisiana
Elijah W. Ramsey III, A. Rangoonwala
2006, Photogrammetric Engineering and Remote Sensing (72) 641-652
In this study, we extended previous work linking leaf spectral changes, dieback onset, and progression of Spartina alterniflora marshes to changes in site-specific canopy reflectance spectra. First, we obtained canopy reflectance spectra (approximately 20 m ground resolution) from the marsh sites occupied during the leaf spectral analyses and from additional...
Emplacement of subaerial pahoehoe lava sheet flows into water: 1990 Kūpaianaha flow of Kilauea volcano at Kaimū Bay, Hawai`i
Susumu Umino, Miyuki Nonaka, James P. Kauahikaua
2006, Bulletin of Volcanology (69) 125-139
Episode 48 of the ongoing eruption of Kilauea, Hawai`i, began in July 1986 and continuously extruded lava for the next 5.5 years from a low shield, Kūpaianaha. The flows in March 1990 headed for Kalapana and inundated the entire town under 15–25 m of lava by the end of August. As the...
In kittiwakes food availability partially explains the seasonal decline in humoral immunocompetence
J. Gasparini, A. Roulin, V.A. Gill, Scott A. Hatch, T. Boulinier
2006, Functional Ecology (20) 457-463
The immune system plays an important role in fitness, and interindividual variation in immunocompetence is due to several factors including food supply.Seasonal variation in food resources may therefore explain why immunocompetence in bird nestlings usually declines throughout the breeding season, with chicks born early in the season receiving...
Geochemical evolution of solutions derived from experimental weathering of sulfide-bearing rocks
L. Munk, G. Faure, R. Koski
2006, Applied Geochemistry (21) 1123-1134
The chemical composition of natural waters is affected by the weathering of geologic materials at or near the surface of the Earth. Laboratory weathering experiments of whole-rock sulfide rocks from the Shoe-Basin Mine (SBM) and the Pennsylvania Mine (PM) from the Peru Creek Basin, Summit County, Colorado, indicate that the...
Measuring permanence of CO2 storage in saline formations: The Frio experiment
Susan D. Hovorka, Sally M. Benson, Christine Doughty, Barry M. Freifeild, Shinichi Sakurai, Thomas M. Daley, Yousif K. Kharaka, Mark H. Holtz, Robert C. Trautz, H. Seay Nance, Larry R. Myer, Kevin G. Knauss
2006, Environmental Geosciences (13) 105-121
If CO2 released from fossil fuel during energy production is returned to the subsurface, will it be retained for periods of time significant enough to benefit the atmosphere? Can trapping be assured in saline formations where there is no history of hydrocarbon accumulation? The Frio experiment in Texas was...
A volcano bursting at the seams: Inflation, faulting, and eruption at Sierra Negra volcano, Galápagos
William W. Chadwick, Dennis J. Geist, Sigurjon Jonsson, Michael P. Poland, Daniel J. Johnson, Charles M. Meertens
2006, Geology (34) 1025-1028
The results of geodetic monitoring since 2002 at Sierra Negra volcano in the Galápagos Islands show that the filling and pressurization of an ∼2-km-deep sill eventually led to an eruption that began on 22 October 2005. Continuous global positioning system (CGPS) monitoring measured >2 m of accelerating inflation leading up...
The Global Boundary Stratotype Section and Point (GSSP) for the base of Changhsingian Stage (Upper Permian)
Y. Jin, Y. Wang, C. Henderson, B. R. Wardlaw, S. Shen, C. Cao
2006, Episodes (29) 175-182
The Global Stratotype Section and Point (GSSP) for the base-Changhsingian Stage is defined at the First Appearance Datum (FAD) of the conodont Clarkina wangi within the lineage from C. longicuspidata to C. wangi at a point 88 cm above the base of the Changxing Limestone in the lower part of...
Environmental and water decision-making in a changing climate
S. Jain, R.S. Pulwarty, T.S. Melis
2006, Conference Paper, Eos
[No abstract available]...
Precessional forcing of lacustrine sedimentation in the late Cenozoic Chemeron Basin, Central Kenya Rift, and calibration of the Gauss/Matuyama boundary
A.L. Deino, J.D. Kingston, J. M. Glen, R.K. Edgar, A. Hill
2006, Earth and Planetary Science Letters (247) 41-60
The fluviolacustrine sedimentary sequence of the Chemeron Formation exposed in the Barsemoi River drainage, Tugen Hills, Kenya, contains a package of five successive diatomite/fluvial cycles that record the periodic development of freshwater lakes within the axial portion of the Central Kenya Rift. The overwhelming abundance in the diatomite of planktonic...
Food webs and parasites in a salt marsh ecosystem
K. D. Lafferty, R. F. Hechinger, J.C. Shaw, K.L. Whitney, A. M. Kuris
S. Collinge, C. Ray, editor(s)
2006, Book chapter, Disease ecology: community structure and pathogen dynamics.
No abstract available at this time...
Tracking magmatic processes through Zr/Hf ratios in rocks and Hf and Ti zoning in zircons: An example from the Spirit Mountain batholith, Nevada
Claiborne L.E. Lowery, C. F. Miller, B.A. Walker, J. L. Wooden, F.K. Mazdab, F. Bea
2006, Mineralogical Magazine (70) 517-543
Zirconium and Hf are nearly identical geochemically, and therefore most of the crust maintains near-chondritic Zr/Hf ratios of ???35-40. By contrast, many high-silica rhyolites and granites have anomalously low Zr/Hf (15-30). As zircon is the primary reservoir for both Zr and Hf and preferentially incorporates Zr, crystallization of zircon controls...
A landscape perspective of the stream corridor invasion and habitat characteristics of an exotic (Dioscorea oppositifolia) in a pristine watershed in Illinois
J.R. Thomas, B. Middleton, D.J. Gibson
2006, Biological Invasions (8) 1103-1113
The spatial distribution of exotics across riparian landscapes is not uniform, and research elaborating the environmental constraints and dispersal behavior that underlie these patterns of distribution is warranted. This study examined the spatial distribution, growth patterns, and habitat constraints of populations of the invasive Dioscorea oppositifolia in a forested stream...
A new reference section for palynostratigraphic zonation of Paleocene rocks in the Rocky Mountain region
D. J. Nichols, R. M. Flores
2006, Mountain Geologist (43) 299-312
A biostratigraphic (palynostratigraphic) zonation of Paleocene rocks was established in the northeastern Wind River Basin near Waltman, Natrona County, Wyoming, in 1978 and subsequently applied extensively by various workers throughout the Rocky Mountain region. Because the original study on which the zonation was based was proprietary, precise details about the...
Sediment mineralogy based on visible and near-infrared reflectance spectroscopy
R. D. Jarrard, Vanden Berg
Rothwell R.G., editor(s)
2006, Geological Society Special Publication 129-140
Visible and near-infrared spectroscopy (VNIS) can be used to measure reflectance spectra (wavelength 350-2500 nm) for sediment cores and samples. A local ground-truth calibration of spectral features to mineral percentages is calculated by measuring reflectance spectra for a suite of samples of known mineralogy. This approach has been tested on...
Denitrification in nitrate-rich streams: Application of N2:Ar and 15N-tracer methods in intact cores
Lesley K. Smith, M.A. Voytek, J.K. Böhlke, J. W. Harvey
2006, Ecological Applications (16) 2191-2207
Rates of benthic denitrification were measured using two techniques, membrane inlet mass spectrometry (MIMS) and isotope ratio mass spectrometry (IRMS), applied to sediment cores from two NO3−‐rich streams draining agricultural land in the upper Mississippi River Basin. Denitrification was estimated simultaneously from measurements of N2:Ar (MIMS) and 15N[N2]...
Gas hydrate transect across northern Cascadia margin
M. Riedel, T. Collett, M. Malone, F. Akiba, M. Blanc-Valleron, M. Ellis, G. Guerin, Y. Hashimoto, V. Heuer, Y. Higashi, M. Holland, P. Jackson, M. Kaneko, M. Kastner, J.-H. Kim, H. Kitajima, P. Long, A. Malinverno, Gwen E. Myers, L. Palekar, J. Pohlman, P. Schultheiss, B. Teichert, M. Torres, A. Trehu, Jingyuan Wang, U. Worthmann, H. Yoshioka
2006, Eos, Transactions, American Geophysical Union (87) 329-330
Gas hydrate is a solid compound mainly comprised of methane and water that is stable under low temperature and high pressure conditions. Usually found in offshore environments with water depths exceeding about 500 meters and in arctic regions associated with permafrost, gas hydrates form an efficient storage system for natural...
