Publications
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Improved prediction and tracking of volcanic ash clouds Improved prediction and tracking of volcanic ash clouds
During the past 30 years, more than 100 airplanes have inadvertently flown through clouds of volcanic ash from erupting volcanoes. Such encounters have caused millions of dollars in damage to the aircraft and have endangered the lives of tens of thousands of passengers. In a few severe cases, total engine failure resulted when ash was ingested into turbines and coating turbine blades...
Authors
Larry G. Mastin, Peter Webley
A guide to differences between stochastic point-source and stochastic finite-fault simulations A guide to differences between stochastic point-source and stochastic finite-fault simulations
Why do stochastic point-source and finite-fault simulation models not agree on the predicted ground motions for moderate earthquakes at large distances? This question was posed by Ken Campbell, who attempted to reproduce the Atkinson and Boore (2006) ground-motion prediction equations for eastern North America using the stochastic point-source program SMSIM (Boore, 2005) in place of the...
Authors
G. M. Atkinson, K. Assatourians, D.M. Boore, K. Campbell, D. Motazedian
A search in strainmeter data for slow slip associated with triggered and ambient tremor near Parkfield, California A search in strainmeter data for slow slip associated with triggered and ambient tremor near Parkfield, California
We test the hypothesis that, as in subduction zones, slow slip facilitates triggered and ambient tremor in the transform boundary setting of California. Our study builds on the study of Peng et al. (2009) of triggered and ambient tremor near Parkfield, California during time intervals surrounding 31, potentially triggering, M ≥ 7.5 teleseismic earthquakes; waves from 10 of these...
Authors
E.F. Smith, J. Gomberg
The increasing wildfire and post-fire debris-flow threat in western USA, and implications for consequences of climate change The increasing wildfire and post-fire debris-flow threat in western USA, and implications for consequences of climate change
In southern California and the intermountain west of the USA, debris flows generated from recently-burned basins pose significant hazards. Increases in the frequency and size of wildfires throughout the western USA can be attributed to increases in the number of fire ignitions, fire suppression practices, and climatic influences. Increased urbanization throughout the western USA...
Authors
Susan H. Cannon, Jerry DeGraff
Microseismicity at the North Anatolian Fault in the Sea of Marmara offshore Istanbul, NW Turkey Microseismicity at the North Anatolian Fault in the Sea of Marmara offshore Istanbul, NW Turkey
The North Anatolian Fault Zone (NAFZ) below the Sea of Marmara forms a “seismic gap” where a major earthquake is expected to occur in the near future. This segment of the fault lies between the 1912 Ganos and 1999 İzmit ruptures and is the only NAFZ segment that has not ruptured since 1766. To monitor the microseismic activity at the main fault branch offshore of Istanbul below the...
Authors
Fatih Bulut, Marco Bohnhoff, William L. Ellsworth, Mustafa Aktar, Georg Dresen
Size distribution of submarine landslides along the U.S. Atlantic margin Size distribution of submarine landslides along the U.S. Atlantic margin
Assessment of the probability for destructive landslide-generated tsunamis depends on the knowledge of the number, size, and frequency of large submarine landslides. This paper investigates the size distribution of submarine landslides along the U.S. Atlantic continental slope and rise using the size of the landslide source regions (landslide failure scars). Landslide scars along the...
Authors
J.D. Chaytor, Uri S. ten Brink, A.R. Solow, B.D. Andrews
Geomagnetic observations on tristan da cunha, south atlantic ocean Geomagnetic observations on tristan da cunha, south atlantic ocean
Few geomagnetic ground observations exist of the Earth's strongest core field anomaly, the South Atlantic Anomaly (SAA). The geomagnetic repeat station on the island Tristan da Cunha, located half-way between South Africa and South America at 37?? 05' S, 12?? 18' W, is therefore of crucial importance. We have conducted several sets of repeat station measurements during magnetically quiet
Authors
J. Matzka, N. Olsen, C.F. Maule, L.W. Pedersen, A.M. Berarducci, S. Macmillan
Diverse lavas from closely spaced volcanoes drawing from a common parent: Emmons Lake Volcanic Center, Eastern Aleutian Arc Diverse lavas from closely spaced volcanoes drawing from a common parent: Emmons Lake Volcanic Center, Eastern Aleutian Arc
Emmons Lake Volcanic Center (ELVC) on the lower Alaskan Peninsula is one of the largest and most diverse volcanic centers in the Aleutian Arc. Since the Middle Pleistocene, eruption of ~ 350 km3 of basalt through rhyolite has produced a 30 km, arc front chain of nested calderas and overlapping stratovolcanoes. ELVC has experienced as many as five major caldera-forming eruptions, the most...
Authors
M. Mangan, T. Miller, C. Waythomas, F. Trusdell, A. Calvert, P. Layer
Photometric changes on Saturn's Titan: Evidence for active cryovolcanism Photometric changes on Saturn's Titan: Evidence for active cryovolcanism
We report infrared spectrophotometric variability on the surface of Saturn's moon Titan detected in images returned by the Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini Saturn Orbiter. The changes were observed at 7°S, 138°W and occurred between October 27, 2005 and January 15, 2006. After that date the surface was unchanged until the most recent observation, March...
Authors
Robert M. Nelson, Lucas W. Kamp, Rosaly Lopes, Dennis L. Matson, Randolph L. Kirk, Bruce W. Hapke, Stephen D. Wall, Mark D. Boryta, Frank E. Leader, William D. Smythe, Karl L. Mitchell, Kevin H. Baines, Ralf Jaumann, Christophe Sotin, Roger N. Clark, Dale P. Cruikshank, Pierre Drossart, Jonathan I. Lunine, Michel Combes, Giancarlo Bellucci, Jean-Pierre Bibring, Fabrizio Capaccioni, Pricilla Cerroni, Angioletta Coradini, Vittorio Formisano, Gianrico Filacchione, Yves Langevin, Thomas B. McCord, Vito Mennella, Philip D. Nicholson, Bruno Sicardy, Patrick G.J. Irwin, John C. Pearl
Possible deep fault slip preceding the 2004 Parkfield earthquake, inferred from detailed observations of tectonic tremor Possible deep fault slip preceding the 2004 Parkfield earthquake, inferred from detailed observations of tectonic tremor
Earthquake predictability depends, in part, on the degree to which sudden slip is preceded by slow aseismic slip. Recently, observations of deep tremor have enabled inferences of deep slow slip even when detection by other means is not possible, but these data are limited to certain areas and mostly the last decade. The region near Parkfield, California, provides a unique convergence of...
Authors
David R. Shelly
Tracking magma volume recovery at Okmok Volcano using GPS and an unscented kalman filter Tracking magma volume recovery at Okmok Volcano using GPS and an unscented kalman filter
Changes beneath a volcano can be observed through position changes in a GPS network, but distinguishing the source of site motion is not always straightforward. The records of continuous GPS sites provide a favorable data set for tracking magma migration. Dense campaign observations usually provide a better spatial picture of the overall deformation field, at the expense of an episodic...
Authors
T. Fournier, Jeffrey T. Freymueller, Peter Cervelli
Features of lava lake filling and draining and their implications for eruption dynamics Features of lava lake filling and draining and their implications for eruption dynamics
Lava lakes experience filling, circulation, and often drainage depending upon the style of activity and location of the vent. Features formed by these processes have proved difficult to document due to dangerous conditions during the eruption, inaccessibility, and destruction of features during lake drainage. Kilauea Iki lava lake, Kilauea, Hawai'i, preserves many such features, because...
Authors
W.K. Stovall, Bruce F. Houghton, A.J.L. Harris, D. A. Swanson