Publications
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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 the M 6.2
Authors
D. P. Schaff, G. H. R. Bokelmann, G. C. Beroza, Felix Waldhause, William L. Ellsworth
Processes of lithosphere evolution: New evidence on the structure of the continental crust and uppermost mantle
We discuss the structure of the continental lithosphere, its physical properties, and the mechanisms that formed and modified it since the early Archean. The structure of the upper mantle and the crust is derived primarily from global and regional seismic tomography studies of Eurasia and from global and regional data on seismic anisotropy. These data as documented in the papers of this special is
Authors
I.M. Artemieva, Walter D. Mooney, E. Perchuc, H. Thybo
Study on 3-D velocity structure of crust and upper mantle in Sichuan-yunnan region, China
Based on the first arrival P and S data of 4 625 regional earthquakes recorded at 174 stations dispersed in the Yunnan and Sichuan Provinces, the 3-D velocity structure of crust and upper mantle in the region is determined, incorporating with previous deep geophysical data. In the upper crust, a positive anomaly velocity zone exists in the Sichuan basin, whereas a negative anomaly velocity zone ex
Authors
C. Wang, Walter D. Mooney, X. Wang, J. Wu, H. Lou, F. Wang
Seismic evidence for a mantle source for mid-Proterozoic anorthosites and implications for models of crustal growth
Voluminous anorthosite intrusions are common in mid-Proterozoic crust. Historically, two end-member models have been proposed for the origin of these anorthosites. In the first model anorthosites derive from fractionation of a mantle source leaving a residue of metagabbro in the lower crust; in the second model anorthosites are the product of partial melting of the lower crust with residual pyroxe
Authors
G. Musacchio, Walter D. Mooney
Seismic structure of the crust and uppermost mantle of North America and adjacent oceanic basins: A synthesis
We present a new set of contour maps of the seismic structure of North America and the surrounding ocean basins. These maps include the crustal thickness, whole-crustal average P-wave and S-wave velocity, and seismic velocity of the uppermost mantle, that is, Pn and Sn. We found the following: (1) The average thickness of the crust under North America is 36.7 km (standard deviation [s.d.] ±8.4 km)
Authors
G.S. Chulick, Walter D. Mooney
Global significance of a sub-Moho boundary layer (SMBL) deduced from high-resolution seismic observations
We infer the fine structure of a sub-Moho boundary layer (SMBL) at the top of the lithospheric mantle from high-resolution seismic observations of Peaceful Nuclear Explosions (PNE) on superlong-range profiles in Russia. Densely recorded seismograms permit recognition of previously unknown features of teleseismic propagation of the well known Pn and Sn phases, such as a band of incoherent, scattere
Authors
K. Fuchs, M. Tittgemeyer, T. Ryberg, F. Wenzel, Walter D. Mooney
On the relations between cratonic lithosphere thickness, plate motions, and basal drag
An overview of seismic, thermal, and petrological evidence on the structure of Precambrian lithosphere suggests that its local maximum thickness is highly variable (140-350 km), with a bimodal distribution for Archean cratons (200-220 km and 300-350 km). We discuss the origin of such large differences in lithospheric thickness, and propose that the lithospheric base can have large depth variations
Authors
I.M. Artemieva, Walter D. Mooney
Seismic images and fault relations of the Santa Monica thrust fault, West Los Angeles, California
In May 1997, the US Geological Survey (USGS) and the University of Southern California (USC) acquired high-resolution seismic reflection and refraction images on the grounds of the Wadsworth Veterans Administration Hospital (WVAH) in the city of Los Angeles (Fig. 1a,b). The objective of the seismic survey was to better understand the near-surface geometry and faulting characteristics of the Santa
Authors
R. D. Catchings, G. Gandhok, M. R. Goldman, D. Okaya
Stratigraphic and structural characterization of the OU-1 area at the former George Air Force Base, Adelanto, southern California
The former George Air Force Base (GAFB), now known as the Southern California Logistics Airport (SCLA), is located in the town of Adelanto, approximately 100 km northeast of Los Angeles, California (Fig. 1). In this report, we present acquisition parameters, data, and interpretations of seismic images that were acquired in the OU-1 area of GAFB during July 1999 (Fig. 2). GAFB is scheduled for conv
Authors
R. D. Catchings, G. Gandhok, M. R. Goldman
Preliminary compilation of data for selected oil test wells in Northern California
Oil test wells can provide information on the depth, age, inclination, porosity, permeability, density, faulting, folding, and organic content of geologic formations mapped at the surface, or on units not recognized in surface outcrops. Formation density, as expressed in sonic and density logs commonly obtained when wells are drilled, has become increasingly important in making a crustal-scale 3-D
Authors
Earl E. Brabb, Charles L. Powell, Thomas M. Brocher
Geophysics: Silent slip on the Cascadia subduction interface
Geodetic satellites of the Global Positioning System (GPS) now permit continuous recording of surface motions around earthquake faults and volcanoes with millimeter precision. Data from distinct points on Earth's surface can be combined to infer the locations of the sources of deformation at depth in the crust. These data are radically altering our understanding of earthquake processes, justifying
Authors
Wayne R. Thatcher
HAZUS 99 estimated annualized earthquake losses for the United States
Recent earthquakes around the world show a pattern of steadily increasing damages and losses. The increases are due primarily to two factors: 1) significant growth in urban areas that are prone to earthquakes; and 2) the vulnerability of the older building stock, even buildings that were constructed within the past twenty years. In the United States, earthquake risk has grown substantially with de