Publications
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The puzzle of the 1996 Bárdarbunga, Iceland, earthquake: no volumetric component in the source mechanism
A volcanic earthquake with Mw 5.6 occurred beneath the Bárdarbunga caldera in Iceland on 29 September 1996. This earthquake is one of a decade-long sequence of events at Bárdarbunga with non-double-couple mechanisms in the Global Centroid Moment Tensor catalog. Fortunately, it was recorded well by the regional-scale Iceland Hotspot Project seismic experiment. We investigated the event with a comp
Authors
Hrvoje Tkalcic, Douglas S. Dreger, Gillian R. Foulger, Bruce R. Julian
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 finite-sou
Authors
G. M. Atkinson, K. Assatourians, D. M. Boore, K. Campbell, D. Motazedian
Stratigraphic controls on saltwater intrusion in the Dominguez Gap area of coastal Los Angeles
The Los Angeles Basin is a densely populated coastal area that significantly depends on groundwater. A part of this groundwater supply is at risk from saltwater intrusion—the impetus for this study. High-resolution seismic-reflection data collected from the Los Angeles–Long Beach Harbor Complex have been combined with borehole geophysical and descriptive geological data from four nearby ~400-m-dee
Authors
Brian D. Edwards, Kenneth D. Ehman, Daniel J. Ponti, Eric G. Reichard, John Tinsley, Robert J. Rosenbauer, Michael T. Land
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 triggered tremor a
Authors
E.F. Smith, J. Gomberg
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 Çınarcık Basin,
Authors
Fatih Bulut, Marco Bohnhoff, William L. Ellsworth, Mustafa Aktar, Georg Dresen
Moderate rates of late Quaternary slip along the northwestern margin of the Basin and Range Province, Surprise Valley fault, northeastern California
The 86-km-long Surprise Valley normal fault forms part of the active northwestern margin of the Basin and Range province in northeastern California. We use trench mapping and radiocarbon, luminescence, and tephra dating to estimate displacements and timing of the past five surface-rupturing earthquakes on the central part of the fault near Cedarville. A Bayesian OxCal analysis of timing constraint
Authors
Stephen F. Personius, Anthony J. Crone, Michael N. Machette, Shannon Mahan, David J. Lidke
Reassessment of probabilistic seismic hazard in the Marmara region
In 1999, the eastern coastline of the Marmara region (Turkey) witnessed increased seismic activity on the North Anatolian fault (NAF) system with two damaging earthquakes (M 7.4 Kocaeli and M 7.2 D??zce) that occurred almost three months apart. These events have reduced stress on the western segment of the NAF where it continues under the Marmara Sea. The undersea fault segments have been recently
Authors
Erol Kalkan, Polat Gülkan, Nazan Yilmaz, Mehmet Çelebi
A grid-doubling finite-element technique for calculating dynamic three-dimensional spontaneous rupture on an earthquake fault
We present a new finite-element technique for calculating dynamic 3-D spontaneous rupture on an earthquake fault, which can reduce the required computational resources by a factor of six or more, without loss of accuracy. The grid-doubling technique employs small cells in a thin layer surrounding the fault. The remainder of the modelling volume is filled with larger cells, typically two or four ti
Authors
Michael Barall
Along-Arc and Back-Arc Attenuation, Site Response, and Source Spectrum for the Intermediate-Depth 8 January 2006 M 6.7 Kythera, Greece, Earthquake
An M 6.7 intermediate-depth (66 km), in-slab earthquake occurring near the island of Kythera in Greece on 8 January 2006 was well recorded on networks of stations equipped with acceleration sensors and with broadband velocity sensors. All data were recorded digitally using recording instruments with resolutions ranging from almost 11 to 24 bits. We use data from these networks to study the distanc
Authors
David M. Boore, A.A. Skarlatoudis, B.N. Margaris, B.P. Costas, C. Ventouzi
Geometry of the Nojima fault at Nojima-Hirabayashi, Japan - I. A simple damage structure inferred from borehole core permeability
The 1995 Kobe (Hyogo-ken Nanbu) earthquake, M = 7.2, ruptured the Nojima fault in southwest Japan. We have studied core samples taken from two scientific drillholes that crossed the fault zone SW of the epicentral region on Awaji Island. The shallower hole, drilled by the Geological Survey of Japan (GSJ), was started 75 m to the SE of the surface trace of the Nojima fault and crossed the fault at
Authors
David A. Lockner, Hidemi Tanaka, Hisao Ito, Ryuji Ikeda, Kentaro Omura, Hisanobu Naka
Premonitory acoustic emissions and stick-slip in natural and smooth-faulted Westerly granite
A stick-slip event was induced in a cylindrical sample of Westerly granite containing a preexisting natural fault by loading at constant confining pressure of 150 MPa. Continuously recorded acoustic emission (AE) data and computer tomography (CT)-generated images of the fault plane were combined to provide a detailed examination of microscale processes operating on the fault. The dynamic stick-sli
Authors
B.D. Thompson, R.P. Young, David A. Lockner
Broadband records of earthquakes in deep gold mines and a comparison with results from SAFOD, California
For one week during September 2007, we deployed a temporary network of field recorders and accelerometers at four sites within two deep, seismically active mines. The ground-motion data, recorded at 200 samples/sec, are well suited to determining source and ground-motion parameters for the mining-induced earthquakes within and adjacent to our network. Four earthquakes with magnitudes close to 2 we
Authors
Arthur F. McGarr, M. Boettcher, Jon Peter B. Fletcher, Russell Sell, Malcolm J. S. Johnston, R. Durrheim, S. Spottiswoode, A. Milev