Publications

This report is the second of two reports on seismic imaging investigations conducted by the U.S. Geological Survey (USGS) during the summers of 1997 and 1998 in the Cherry Valley area in California (Figure 1a). In the first report (Catchings et al., 1999), data and interpretations were presented for four seismic imaging profiles (CV-1, CV-2, CV-3, and CV-4) acquired during the summer of...

McVCO is a microcontroller-based frequency generator that replaces the voltage controlled oscillator (VCO) used in the analog telemetry of seismic data. It accepts low-level signals from a seismometer and produces a frequency modulated subcarrier suitable for radio or telephone links to a data collection site. McVCO was designed for the purpose of improving the analog telemetry of...

The method for estimating the site effect on ground motion specified by Borcherdt (1994a, 1994b) is briefly introduced in the paper. This method and the detail geological data and site classification data in San Francisco bay area of California, the United States, are applied to simulate the influenced field of scenario earthquake by GIS technology, and the software for simulating has...

Eaton (1975), Bakun and Dratler (1976), Eaton (1977), Healy and O’Neil (1977), Asten (1977), Stewart and O'Neill (1980), Liu and Peselnick (1986), Eaton (1991), Rodgers et al. (1995), and many others (see Asten (1977) for a list of earlier references) have presented formulae for calculating the damped generator constant (or motor constant), and the damping constant (or fractional damping...

The focus of the Southern California Earthquake Hazards project is to identify the landslide and earthquake hazards and related ground-deformation processes occurring in the offshore areas that have significant potential to impact the inhabitants of the Southern California coastal region. The project activity is supported through the Coastal and Marine Geology Program of the Geologic...

Displacements derived from the accelerogram recordings of the 1999 Chi-Chi, Taiwan earthquake at stations TCU078 and TCU129 show drifts when only a simple baseline derived from the pre-event portion of the record is removed from the records. The appearance of the velocity and displacement records suggests that changes in the zero-level of the acceleration are responsible for these drifts...

Studies of Yucca Mountain, Nevada, as a potential geologic nuclear-waste repository began in the late 1970s and continued to 1988 when the U. S. Nuclear Regulatory Commission determined that the quality assurance (QA) programs in place were not adequate and demanded restructuring to a new QA program. The new QA program was accepted in 1989, but many activities did not resume until new...

Following the 1994 Mw=6.7 Northridge earthquake, a 65‐km‐long, north‐south array of 11 geodetic monuments was established across the rupture. The array was surveyed with GPS ten times in the 4.25 yr after the earthquake. Although there is evidence for modest nonlinear postseismic relaxation in the first few weeks after the Northridge earthquake, the deformation in the subsequent four...

A linear array of 15 geodetic monuments was installed in 1993 across the rupture zone of the 1964 Alaska earthquake (Mw = 9.2). The array extends from Middleton Island (at the edge of the continental shelf and 80 km from the Alaska‐Aleutian trench) to north of Palmer, Alaska (380 km from the trench), in the approximate direction of Pacific‐North American plate convergence (N15.5°W). The...

We discuss three interconnected processes that occur during continental compression and extension: delamination of the lower crust and sub-crustal lithosphere, escape tectonics (i.e., lateral crustal flow), and crustal uplift. We combine calculations of lithospheric viscosity–depth curves with geologic observations and seismic images of the deep crust to infer the mechanisms controlling...

No abstract avaialable.

Satellite interferometric synthetic aperture radar is uniquely suited to monitoring year-to-year deformation of the entire Yellowstone caldera (about 3000 square kilometers). Sequential interferograms indicate that subsidence within the caldera migrated from one resurgent dome to the other between August 1992 and August 1995. Between August 1995 and September 1996, the caldera region...