Publications
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Eruption dynamics at Mount St. Helens imaged from broadband seismic waveforms: Interaction of the shallow magmatic and hydrothermal systems
The current eruption at Mount St. Helens is characterized by dome building and shallow, repetitive, long-period (LP) earthquakes. Waveform cross-correlation reveals remarkable similarity for a majority of the earthquakes over periods of several weeks. Stacked spectra of these events display multiple peaks between 0.5 and 2 Hz that are common to most stations. Lower-amplitude very-long-period (VLP)
Authors
G.P. Waite, B. A. Chouet, P.B. Dawson
Broadband seismic measurements of degassing activity associated with lava effusion at Popocatépetl Volcano, Mexico
From November 1999 through July 2000, a broadband seismic experiment was carried out at Popocatépetl Volcano to record seismic activity over a wide period range (0.04–100 s). We present an overview of the seismicity recorded during this experiment and discuss results of analyses of long-period (LP) and very-long-period (VLP) seismic signals recorded at stations nearest to the crater over a four-mo
Authors
Alejandra Arciniega-Ceballos, Bernard A. Chouet, Phillip Dawson, Guenter Asch
Effects of scoria-cone eruptions upon nearby human communities
Scoria-cone eruptions are typically low in volume and explosivity compared with eruptions from stratovolcanoes, but they can affect local populations profoundly. Scoria-cone eruption effects vary dramatically due to eruption style, tephra blanket extent, climate, types of land use, the culture and complexity of the affected group, and resulting governmental action. A comparison of a historic erupt
Authors
M.H. Ort, M.D. Elson, K.C. Anderson, W. A. Duffield, J.A. Hooten, D. E. Champion, G. Waring
Landslides triggered by the 8 October 2005 Kashmir earthquake
The 8 October 2005 Kashmir earthquake triggered several thousand landslides. These were mainly rock falls and debris falls, although translational rock and debris slides also occurred. In addition, a sturzstrom (debris avalanche) comprising ??? 80??million m3 buried four villages and blocked streams to create two lakes. Although landsliding occurred throughout the region, covering an area of > 750
Authors
L.A. Owen, U. Kamp, G.A. Khattak, E. L. Harp, D. K. Keefer, M.A. Bauer
The last 1000 years of natural and anthropogenic low-oxygen bottom-water on the Louisiana shelf, Gulf of Mexico
The relative abundance of three species of low-oxygen tolerant benthic foraminifers, the PEB index, in foraminiferal assemblages from sediment cores is used to trace the history of low-oxygen bottom-water conditions on the Louisiana shelf. Analyses of a network of box cores indicate that the modern zone of chronic seasonal hypoxia off the Mississippi Delta began to develop around 1920 and was well
Authors
L.E. Osterman, R. Z. Poore, P.W. Swarzenski
Composition and origin of the Dewar geochemical anomaly
Dewar crater is a 50-km diameter impact structure located in the highlands northwest of the South Pole–Aitken basin on the lunar farside. A low-albedo area with enhanced Th and Sm values is centered east-northeast of Dewar crater. This area also exhibits elevated FeO abundances (9.0–16.6 wt %) and TiO2 values (0.6–2 wt %). The range of FeO and TiO2 abundances determined for the darkest portions of
Authors
Samuel J. Lawrence, B. Ray Hawke, Jeffrey J. Gillis-Davis, G. Jeffrey Taylor, David J. Lawrence, Joshua T. Cahill, Justin Hagerty, Paul G. Lucey, Gregory A. Smith, Klaus Keil
Non-spore forming eubacteria isolated at an altitude of 20,000 m in Earth's atmosphere: extended incubation periods needed for culture-based assays
On 13 August 2004, an atmospheric sample was collected at an altitude of 20,000 m along a west to east transect over the continental United States by NASA’s Stratospheric and Cosmic Dust Program. This sample was then shipped to the US Geological Survey’s Global Desert Dust program for microbiological analyses. This sample, which was plated on a low nutrient agar to determine if cultivable microorg
Authors
Dale W. Griffin
Effects of topography and crustal heterogeneities on the source estimation of LP event at Kilauea volcano
The main goal of this study is to improve the modelling of the source mechanism associated with the generation of long period (LP) signals in volcanic areas. Our intent is to evaluate the effects that detailed structural features of the volcanic models play in the generation of LP signal and the consequent retrieval of LP source characteristics. In particular, effects associated with the presence
Authors
S. Cesca, J. Battaglia, T. Dahm, E. Tessmer, S. Heimann, Paul G. Okubo
The imaging performance of the SRC on Mars Express
The Mars Express spacecraft carries the pushbroom scanner high-resolution stereo camera (HRSC) and its added imaging subsystem super resolution channel (SRC). The SRC is equipped with its own optical system and a 1024×1024 framing sensor. SRC produces snapshots with 2.3 m ground pixel size from the nominal spacecraft pericenter height of 250 km, which are typically embedded in the central part of
Authors
J. Oberst, G. Schwarz, T. Behnke, H. Hoffmann, K.-D. Matz, J. Flohrer, H. Hirsch, T. Roatsch, F. Scholten, E. Hauber, B. Brinkmann, R. Jaumann, D. Williams, Randolph L. Kirk, T. Duxbury, C. Leu, G. Neukum
Post-wildfire erosion response in two geologic terrains in the western USA
Volumes of eroded sediment after wildfires vary substantially throughout different geologic terrains across the western United States. These volumes are difficult to compare because they represent the response to rainstorms and runoff with different characteristics. However, by measuring the erosion response as the erodibility efficiency of water to detach and transport sediment on hillslopes and
Authors
J. A. Moody, D.A. Martin, S.H. Cannon
The Breccia Museo formation, Campi Flegrei, southern Italy: Geochronology, chemostratigraphy and relationship with the Campanian Ignimbrite eruption
The Breccia Museo is one of the most debated volcanic formations of the Campi Flegrei volcanic district. The deposit, made up of six distinctive stratigraphic units, has been interpreted by some as the proximal facies of the major caldera-forming Campanian Ignimbrite eruption, and by others as the product of several, more recent, independent and localized events. New geochemical and chemostratigra
Authors
L. Fedele, C. Scarpati, M. Lanphere, L. Melluso, V. Morra, A. Perrotta, G. Ricci
Mantle structure beneath the western edge of the Colorado Plateau
Teleseismic traveltime data are inverted for mantle Vp and Vs variations beneath a 1400 km long line of broadband seismometers extending from eastern New Mexico to western Utah. The model spans 600 km beneath the moho with resolution of ~50 km. Inversions show a sharp, large-magnitude velocity contrast across the Colorado Plateau-Great Basin transition extending ~200 km below the crust. Also image
Authors
C.R. Sine, D. Wilson, W. Gao, S.P. Grand, R. Aster, J. Ni, W. S. Baldridge