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Publications

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Shallow seismic imaging of folds above the Puente Hills blind-thrust fault, Los Angeles, California Shallow seismic imaging of folds above the Puente Hills blind-thrust fault, Los Angeles, California

High-resolution seismic reflection profiles image discrete folds in the shallow subsurface (
Authors
Thomas L. Pratt, John H. Shaw, James F. Dolan, Shari A. Christofferson, Robert Williams, Jack K. Odum, Andreas Plesch

The proximal part of the giant submarine Wailau landslide, Molokai, Hawaii The proximal part of the giant submarine Wailau landslide, Molokai, Hawaii

The main break-in-slope on the northern submarine flank of Molokai at -1500 to -1250 m is a shoreline feature that has been only modestly modified by the Wailau landslide. Submarine canyons above the break-in-slope, including one meandering stream, were subaerially carved. Where such canyons cross the break-in-slope, plunge pools may form by erosion from bedload sediment carried down the...
Authors
D.A. Clague, J.G. Moore

Magnetic fields over active tectonic zones in ocean Magnetic fields over active tectonic zones in ocean

The aim of our work is to estimate the electromagnetic effects that can be detected in the submarine zones with hydrothermal activity. It is known that meso-scale flows appear in the regions over underwater volcanoes or hot rocks. Their origin is connected with heat flux and hot jets released from underwater volcanoes or faults in a sea bottom. Values of mean velocities and turbulent...
Authors
Yu. A. Kopytenko, P.M. Serebrianaya, L.V. Nikitina, A.W. Green

Fault structure and mechanics of the Hayward Fault, California from double-difference earthquake locations Fault structure and mechanics of the Hayward Fault, California from double-difference earthquake locations

The relationship between small-magnitude seismicity and large-scale crustal faulting along the Hayward Fault, California, is investigated using a double-difference (DD) earthquake location algorithm. We used the DD method to determine high-resolution hypocenter locations of the seismicity that occurred between 1967 and 1998. The DD technique incorporates catalog travel time data and...
Authors
Felix Waldhause, William L. Ellsworth

Fault structure and kinematics of the Long Valley Caldera region, California, revealed by high-accuracy earthquake hypocenters and focal mechanism stress inversions Fault structure and kinematics of the Long Valley Caldera region, California, revealed by high-accuracy earthquake hypocenters and focal mechanism stress inversions

We have determined high-resolution hypocenters for 45,000+ earthquakes that occurred between 1980 and 2000 in the Long Valley caldera area using a double-difference earthquake location algorithm and routinely determined arrival times. The locations reveal numerous discrete fault planes in the southern caldera and adjacent Sierra Nevada block (SNB). Intracaldera faults include a series of...
Authors
Stephanie G. Prejean, William L. Ellsworth, Mark Zoback, Felix Waldhauser

Spatial and temporal deformation along the northern San Jacinto fault, southern California: Implications for slip rates Spatial and temporal deformation along the northern San Jacinto fault, southern California: Implications for slip rates

The San Timoteo badlands is an area of uplift and erosional dissection that has formed as a result of late Quaternary uplift along a restraining bend in the San Jacinto fault, of the San Andreas fault system in southern California. This bend currently is located in a region where late Quaternary deposits and associated surfaces have formed in lower San Timoteo Canyon. We have used...
Authors
K.J. Kendrick, D. M. Morton, S. G. Wells, R.W. Simpson

Geomorphic studies of landslides in the Tully Valley, New York: Implications for public policy and planning Geomorphic studies of landslides in the Tully Valley, New York: Implications for public policy and planning

On April 27, 1993, a large landslide in the Tully Valley, Onondaga County, NY, destroyed three houses and resulted in the evacuation of four others; it also triggered a loss of potable drinking water for about 15 homes north of the slide area and affected a total of 20 ha of land. In the 7 years following this slide, several studies have been conducted by federal and state environmental...
Authors
D. L. Pair, William M. Kappel

High-resolution image of Calaveras Fault seismicity High-resolution image of Calaveras Fault seismicity

By measuring relative earthquake arrival times using waveform cross correlation and locating earthquakes using the double difference technique, we are able to reduce hypocentral errors by 1 to 2 orders of magnitude over routine locations for nearly 8000 events along a 35-km section of the Calaveras Fault. This represents ∼92% of all seismicity since 1984 and includes the rupture zone of...
Authors
D. P. Schaff, G. H. R. Bokelmann, G. C. Beroza, Felix Waldhause, William L. Ellsworth

Comparing landslide inventories: The map depends on the method Comparing landslide inventories: The map depends on the method

Landslide inventory maps are generally prepared by interpreting the geomorphic expression of landsliding on aerial photos, topographic maps, or on the ground. Distinctive landslide geomorphology allows the recognition and mapping of landslides, although there are always landslides that have very subtle expression and are not identified. The difficulties of mapping landslides based on...
Authors
C.J. Wills, T.P. McCrink

Remotely sensed geology from lander-based to orbital perspectives: Results of FIDO rover May 2000 field tests Remotely sensed geology from lander-based to orbital perspectives: Results of FIDO rover May 2000 field tests

Blind field tests of the Field Integration Design and Operations (FIDO) prototype Mars rover were carried out 7-16 May 2000. A Core Operations Team (COT), sequestered at the Jet Propulsion Laboratory without knowledge of test site location, prepared command sequences and interpreted data acquired by the rover. Instrument sensors included a stereo panoramic camera, navigational and hazard...
Authors
B. Jolliff, A. Knoll, R.V. Morris, J. Moersch, H. McSween, M. Gilmore, R. Arvidson, R. Greeley, Kenneth E. Herkenhoff, S. Squyres

Separation of site effects and structural focusing in Santa Monica, California: A study of high-frequency weak motions from earthquakes and blasts recorded during the Los Angeles Region Seismic Experiment Separation of site effects and structural focusing in Santa Monica, California: A study of high-frequency weak motions from earthquakes and blasts recorded during the Los Angeles Region Seismic Experiment

Near-surface site factors and the effects of deep structural focusing were estimated in the Santa Monica Mountains and Santa Monica, California, from a portable array of 75 seismic stations deployed during the Los Angeles Region Seismic Experiment, Phase II (LARSE II). The objective was to examine further the origin of seismic wave amplification in the region of intense damage south of...
Authors
S. Baher, P.M. Davis, G. Fuis
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