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San Francisco’s 1906 Quake Revisited

March 13, 2006 – A century after the great San Francisco earthquake killed more than 3,000 people, a federal scientist from the Bay Area will visit fault-riddled Utah for a lecture titled “The 1906 Earthquake – lessons learned, lessons forgotten and future directions.”

Geophysicist Mary Lou Zoback, a senior research scientist for the U.S. Geological Survey in Menlo Park, Calif., will deliver the free public lecture at 7 p.m. Wednesday March 22 in the auditorium of the main downtown Salt Lake City Public Library at 210 East 400 South.

The lecture is sponsored by the University of Utah Seismograph Stations and the Utah Seismic Safety Commission. It will serve as a prelude to Utah‘s Earthquake Preparedness Week during April 2-8 and to the celebration of the 40th anniversary of the University of Utah Seismograph Stations on April 11.

“As California commemorates the 100th anniversary of the devastating 1906 San Francisco earthquake – more than 3,000 dead in San Francisco alone and 225,000 left homeless – we in Utah should use this occasion as a reminder of how devastating earthquakes can be,” says Kristine Pankow, a University of Utah seismologist helping to organize the lecture.

“The talk will highlight the disaster of the earthquake, but also will focus on how this earthquake changed the study of earthquakes,” says Pankow, a research assistant professor of geology and geophysics. “In preparation for the 100th anniversary, data from the 1906 earthquake has been reanalyzed and new results will be shown. Mary Lou has also indicated that she will use examples related to the Salt Lake region. She believes that this anniversary is not just for Californians.”

The San Francisco earthquake of April 18, 1906, measured 7.9 in magnitude and violently awoke the city at 5:12 a.m. as the northern San Andreas Fault ruptured.

“The 1906 earthquake and resulting firestorm over the next three days left San Francisco devastated and significant damage throughout northern California,” Zoback wrote in a summary of her lecture. “The centennial of this major natural disaster affords an opportunity to commemorate the cultural and social response to this historic event and to highlight a century of progress in understanding earthquake hazards and reducing the risks they pose.”

Subsequent analysis of damaged buildings and other structures “concluded that destruction was closely related to building design and construction – a painful lesson oft repeated around the world,” Zoback added.

Utah‘s Wasatch fault, which runs north-to-south along the base of the Wasatch Range, is a different kind of fault than the San Andreas, but also is considered capable of disastrous earthquakes between 6.8 and 7.6 in magnitude.

A 1994 casualty estimate projected that a magnitude-7.5 quake on the Salt Lake Valley segment of the Wasatch fault could kill up to 7,600 people, seriously injure another 44,000 and cause $12 billion in damage and another $6 billion in economic losses. More recent estimates by Utah officials state that a magnitude-7 quake on the same stretch of fault could kill up to 2,200 people, injure more than 24,000 others and cause damage and economic losses ranging from $25 billion to $38 billion.

Zoback is a graduate of Stanford University, earning bachelor’s and doctoral degrees in geophysics in 1974 and 1978, respectively. She has been employed ever since by the U.S. Geological Survey, working as research geophysicist in the earthquake hazards program, then chief scientist of the western hazards team and now as a senior research scientist. She also serves as regional coordinator for the agency’s Northern California Earthquake Hazard Program.

She is respected for her research on the relationship between earthquakes and state of stress in the Earth’s crust. She is a member of the National Academy of Sciences and a past president of the Geological Society of America.

Zoback is delivering a series of lectures on the 1906 earthquake under the auspices of the Incorporated Research Institutions for Seismology and the Seismological Society of America.

An abstract of Zoback’s talk and professional information about her are at:

A U.S. Geological Survey web page on the 1906 quake centennial is at:

The University of Utah Seismograph Stations website is: