Publications
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An alternative approach to characterize nonlinear site effects An alternative approach to characterize nonlinear site effects
This paper examines the rationale of a method of nonstationary processing and analysis, referred to as the Hilbert-Huang transform (HHT), for its application to a recording-based approach in quantifying influences of soil nonlinearity in site response. In particular, this paper first summarizes symptoms of soil nonlinearity shown in earthquake recordings, reviews the Fourier-based...
Authors
R.R. Zhang, S. Hartzell, J. Liang, Y. Hu
Monitoring eruptive activity at Mount St. Helens with TIR image data Monitoring eruptive activity at Mount St. Helens with TIR image data
Thermal infrared (TIR) data from the MASTER airborne imaging spectrometer were acquired over Mount St. Helens in Sept and Oct, 2004, before and after the onset of recent eruptive activity. Pre‐eruption data showed no measurable increase in surface temperatures before the first phreatic eruption on Oct 1. MASTER data acquired during the initial eruptive episode on Oct 14 showed maximum...
Authors
R.G. Vaughan, S.J. Hook, M.S. Ramsey, V.J. Realmuto, D.J. Schneider
Water alteration of rocks and soils on Mars at the Spirit rover site in Gusev crater Water alteration of rocks and soils on Mars at the Spirit rover site in Gusev crater
Gusev crater was selected as the landing site for the Spirit rover because of the possibility that it once held a lake. Thus one of the rover's tasks was to search for evidence of lake sediments. However, the plains at the landing site were found to be covered by a regolith composed of olivine-rich basaltic rock and wind-blown 'global' dust. The analyses of three rock interiors exposed...
Authors
L.A. Haskin, A. Wang, B.L. Jolliff, H.Y. McSween, B. C. Clark, D.J. Des Marais, S. M. McLennan, N.J. Tosca, J.A. Hurowitz, J.D. Farmer, A. Yen, S. W. Squyres, R. E. Arvidson, G. Klingelhofer, C. Schroder, P.A. De Souza, D. W. Ming, Ralf Gellert, J. Zipfel, J. Bruckner, J.F. Bell, Kenneth E. Herkenhoff, P. R. Christensen, S. Ruff, D. Blaney, S. Gorevan, N.A. Cabrol, L. Crumpler, J. Grant, L. Soderblom
InSAR studies of Alaska volcanoes InSAR studies of Alaska volcanoes
Interferometric synthetic aperture radar (InSAR) is a remote sensing technique capable of measuring ground surface deformation with sub-centimeter precision and spatial resolution in tens-ofmeters over a large region. This paper describes basics of InSAR and highlights our studies of Alaskan volcanoes with InSAR images acquired from European ERS-l and ERS-2, Canadian Radarsat-l, and...
Authors
Zhong Lu, Chuck Wicks, Daniel Dzurisin, John A. Power
Global Positioning System measurements on the island of Hawai`i: 1997 through 2004 Global Positioning System measurements on the island of Hawai`i: 1997 through 2004
This report summarizes GPS data and observations collected between 1997 and 2004 on the island of Hawai‘i with static surveying and continuously recording instruments. On Kīlauea, the long-term deformation field is dominated by steady southeastern velocities of more than 6 cm/year and uplift of about 2 cm/yr at stations on the south flank (with respect to a fixed Pacific Plate)...
Authors
Asta Miklius, Peter Cervelli, Maurice Sako, Michael Lisowski, Susan Owen, Paul Segal, James Foster, Kevan Kamibayashi, Ben Brooks
Gravity and magnetic data along a seismic refraction-reflection line in northwest Nevada and northeast California Gravity and magnetic data along a seismic refraction-reflection line in northwest Nevada and northeast California
No abstract available.
Authors
Janet E. Tilden, David A. Ponce, Jonathan M. G. Glen, Kathleen D. Gans
Argon geochronology of late Pleistocene to Holocene Westdahl volcano, Unimak Island, Alaska Argon geochronology of late Pleistocene to Holocene Westdahl volcano, Unimak Island, Alaska
High-precision 40Ar/39Ar geochronology of selected lavas from Westdahl Volcano places time constraints on several key prehistoric eruptive phases of this large active volcano. A dike cutting old pyroclastic-flow and associated lahar deposits from a precursor volcano yields an age of 1,654+/-11 k.y., dating this precursor volcano as older than early Pleistocene. A total of 11...
Authors
Andrew T. Calvert, Richard B. Moore, Robert G. McGimsey
2003 volcanic activity in Alaska and Kamchatka: Summary of events and response of the Alaska Volcano Observatory 2003 volcanic activity in Alaska and Kamchatka: Summary of events and response of the Alaska Volcano Observatory
The Alaska Volcano Observatory (AVO) monitors the more than 40 historically active volcanoes of the Aleutian Arc. Of these, 24 were considered monitored in real time with short-period seismic instrument networks as of the end of 2003. The AVO core monitoring program also includes daily analysis of satellite imagery, observation over flights, and compilation of pilot reports and reports...
Authors
Robert G. McGimsey, Christina A. Neal, Olga Girina
Models of lithosphere and asthenosphere anisotropic structure of the Yellowstone hot spot from shear wave splitting Models of lithosphere and asthenosphere anisotropic structure of the Yellowstone hot spot from shear wave splitting
Teleseismic shear wave splitting measured at 56 continuous and temporary seismographs deployed in a 500 km by 600 km area around the Yellowstone hot spot indicates that fast anisotropy in the mantle is parallel to the direction of plate motion under most of the array. The average split time from all stations of 0.9 s is typical of continental stations. There is little evidence for plume...
Authors
Gregory P. Waite, D.L. Schutt, Robert B. Smith
The 2003 eruption of Anatahan volcano, Commonwealth of the Northern Mariana Islands: Chronology, volcanology, and deformation The 2003 eruption of Anatahan volcano, Commonwealth of the Northern Mariana Islands: Chronology, volcanology, and deformation
The first historical eruption on Anatahan Island occurred on 10 May 2003 from the east crater of the volcano. The eruption was preceded by several hours of seismicity. Two and a half hours before the outbreak, the number of earthquakes surged to more than 100 events per hour. At 0730 UTC, the Washington Volcanic Ash Advisory Center issued an ash advisory. Although the eruption lasted for...
Authors
F. A. Trusdell, R. B. Moore, M. Sako, R.A. White, S.K. Koyanagi, R. Chong, J.T. Camacho
Pitted cones and domes on Mars: Observations in Acidalia Planitia and Cydonia Mensae using MOC, THEMIS, and TES data Pitted cones and domes on Mars: Observations in Acidalia Planitia and Cydonia Mensae using MOC, THEMIS, and TES data
Domes and cones with summit pits located in Acidalia Planitia and Cydonia Mensae were studied using MOC and THEMIS images and a TES‐derived thermal inertia map. North of 40.5°N latitude, the features have a dome‐like morphology, and south of that latitude, the morphology is more cone‐like. Layering is apparent in the summit craters of fresher looking southern cones, and asymmetric aprons...
Authors
William H. Farrand, Lisa R. Gaddis, Laszlo P. Keszthelyi
Hazard calculations for the WGCEP-2002 earthquake forecast using OpenSHA and distributed object technologies Hazard calculations for the WGCEP-2002 earthquake forecast using OpenSHA and distributed object technologies
We present seismic-hazard calculations for what is arguably the most sophisticated earthquake forecast ever developed—the model by the 2002 Working Group on California Earthquake Probabilities (2003), or WGCEP-2002 as referred to hereafter. These calculations have been made possible by developments in both OpenSHA (Field et al., 2003) and the Information Technology Research (ITR)...
Authors
Edward H. Field, N. Gupta, Vipin Gupta, Michael L. Blanpied, Phillip J. Maechling, Thomas H. Jordan