Research Interests

Key Words: Site Response, Strong Ground Motion, Engineering Seismology, Borehole Seismology, Earthquake Source Mechanics and Dynamics.

My research interests are focused on engineering seismology and strong ground motion. Through analysis and understanding of past ground motion data, we can better predict the level and variation of future ground motion in metropolitan regions. Strong ground motion is a combination of the effects of the local site conditions, the source to path geometry, and earthquake source dynamics. Only by understanding all of these contributions can we better predict the hazard from future damaging earthquakes.

The focus of much of my research in the last few years has been using borehole instrumentation to better understand the effects of near-surface soils on ground motion. The NEES@UCSB project, which is maintained by myself and other researchers and technicians at UCSB, is an example of an experiment designed with this in mind.

Geotechnical Strong Motion Array Observatories

The Garner Valley Array component of NEES@UCSB


The Wildlife Liquefaction Array component of NEES@UCSB


The Borrego Valley Array


The Hollister Earthquake Observatory


The SCEC Borehole Instrumentation Program


The USGS/ANSS Anchorage Delaney Park Array


Other Research Topics

Correlation between surface and borehole site charateristics (including geology, P- and S-wave velocity, depth to bedrock, etc...) with ground motion amplification. "Site Response in Southern California for Probabilistic Seismic Hazard Analysis", BSSA 2000 article (PDF file).

Establishing the "reference" site in seismic hazard estimation. Is a surface rock site a good reference site? "What is a Reference Site?", BSSA 1996 article (PDF file).

Site response study using aftershocks and mainshock data from the 1994 Northridge earthquake