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.
