Publications

No abstract available.

A swarm of 12 widely felt earthquakes occurred between August 28 and September 21, 2001, in the area west of the town of Trinidad, Colorado. The earthquakes ranged in magnitude between 2.8 and 4.6, and the largest event occurred on September 5, eight days after the initial M 3.4 event. The nearest permanent seismograph station to the swarm is about 290 km away, resulting in large uncertainties i

No abstract available.

Modified Mercalli Intensity (MMI) assignments for earthquakes in eastern North America (ENA) were used by Bakun et al. (submitted) to develop a model for eastern North America for estimating the location and moment magnitude M of earthquakes from MMI observations. MMI assignments for most of the earthquakes considered by Bakun et al. (submitted) are published. MMI assignments for 6 other earthquak

Borehole and other geotechnical information collected at the strong-motion recording sites of the Northridge earthquake of January 17, 1994 provide an important new basis for the characterization of local site conditions. These geotechnical data, when combined with analysis of strong-motion recordings, provide an empirical basis to evaluate site coefficients used in current versions of US building

It is very unusual that nine large earthquakes of similar magnitudes (M = 6.1-6.8) occured within a very small area and a very short period of time (1997-1998) in Jiashi of Xinjiang Province, Northwest China. This paper analyzes the observed data of the aftershocks in the Jiashi earthquake region for studying the generating mechanism and deep structural background of the Jiashi strong earthquake s

No abstract available.

This chapter summarizes experimental observations and related theoretical developments of faulted and intact rock properties related to earthquake nucleation, failure and dynamic slip. We will be concerned primarily with earthquakes occurring in the brittle crust. Intermediate and deep-focus earthquakes have unique mechanical considerations that are discussed in Section 7. We focus on repeatable l

The strength of active fault zones, i.e., the shear stress level required to cause fault slip, is fundamental to understanding the physics of earthquakes and to assessing earthquake hazard. Although many researchers have concluded that fault zones are weak (shear stresses 10 MPa or less averaged between 0 and ˜20 km depth), others maintain that faults are strong (˜100 MPa average of an approximate

As of the time of this writing, the San Francisco Bay region is home to about 6.8 million people, ranking fifth among population centers in the United States. Most of these people live on the coastal lands along San Francisco Bay, the Sacramento River delta, and the Pacific coast. The region straddles the tectonic boundary between the Pacific and North American Plates and is crossed by several str

The purpose of this chapter is to provide a summary of the seismic velocity structure of the continental lithosphere, i.e., the crust and uppermost mantle. We define the crust as the outer layer of the Earth that is separated from the underlying mantle by the Mohorovičić discontinuity (Moho). We adopted the usual convention of defining the seismic Moho as the level in the Earth where the seismic c

Before the August 1999 Izmit (Kocaeli), Turkey, earthquake, theoretical studies of earthquake ruptures and geological observations had provided estimates of how far an earthquake might jump to get to a neighboring fault. Both numerical simulations and geological observations suggested that 5 km might be the upper limit if there were no transfer faults. The Izmit earthquake appears to have followed