Serving professionals in engineering, environmental, and groundwater geology
since 1957

MONTHLY DINNER MEETING

Date: Tuesday, June 17, 2003
Location: Veterans of Foreign Wars Hall,
3801 Market Street, Ventura, CA
Directions: http://www.coastgeologicalsociety.org
Time: 6:00 p.m. - Social Hour;
7:00 p.m. – Dinner;
8:00 p.m. – Presentation

Cost: $12 per person with reservations, $17 at the door, $7 for students.
Reservations: Call Dave Brown (805) 653-7975 or Fax (805) 653-7452, or email cgs.rsvp@sbcglobal.net, by
12:00 p.m., Friday, June 13, 2003

SPEAKER: Dr. Kerry Sieh
TITLE: The Denali, Alaska Earthquake of 2002

ABSTRACT

Field investigations have revealed that the Mw7.9 Denali fault earthquake of November 3, 2002 resulted from 325 kilometers of breaks along three distinct faults. Rupture proceeded unilaterally from west to east, beginning with a 40-km break along the north-dipping Susitna Glacier fault. The principal surface break was along a 215 km-long stretch of the Denali fault, where dextral offsets averaged about 5 m but ramped upward toward the east. Farther east, the Totschunda fault sustained discontinuous dextral offsets of = 2 m along a 69 km length.

This tripartite rupture ranks among Earth's largest strike-slip events of the past two centuries, comparable to the great California events of 1857 and 1906. The rupture raises important questions about the nature of seismic faulting, Alaskan active tectonics, and the possibility of forecasting future events in Alaska (as well as in California). The survival of the Trans-Alaska Pipeline at its crossing of the rupture underscores the relevance of geologic hazard assessment in the design of critical structures.

BIO

Dr. Sieh is a Professor of Geology in the Seismological Laboratory at the California Institute of Technology, and a Senior Consultant and Partner with Earth Consultants International. Dr. Sieh's principal research involves the study of earthquakes by geological methods. His documentation of ancient earthquakes and slip rates along the San Andreas, San Jacinto and other California faults set the standard for quantitative estimates of the probability of future destructive earthquakes in California.

Currently Dr. Sieh's work is in Taiwan, Turkey, Indonesia and California. He has served on numerous scientific peer-review committees and advisory panels for State and Federal governments and has served as a consultant to various public utilities, municipalities and geotechnical firms. He formed and led the earthquake geology working group of the Southern California Earthquake Center.