College rests on unstable land
Fault proximity poses danger
Published: Thursday, October 15, 2009
Updated: Thursday, October 15, 2009 04:10
Regarded by the Earthquake Engineering Research Institute as the most at-risk fault in the nation, the Hayward Fault runs directly through the college and is overdue for a major seismic burst.
Beginning in San Jose and traveling north through the Berkeley hills, the fault runs through Lot 10, Lot 1 and the Bus Transfer Center, and outlets into the San Pablo Bay.
Surrounding areas are also at particular risk, as faults tend to have many small surrounding fractures. The Gymnasium, Student Activities Building and Student Services Center rest on some of the Hayward Fault Zone fractures.
Having produced an earthquake at an average of 140 years apart in the last five occurrences, Oct. 21 marks the 141st year since the Hayward Fault's last quake in 1868, according to the United States Geological Survey (USGS). The temblor measured a 6.8-7.0 magnitude and caused 30 deaths and millions of dollars in property damage.
The looming Hayward Fault earthquake is expected to be of similar magnitude to its predecessor, but will affect an extraordinarily more developed and populated society.
According to a 2008 release by the USGS, if the 1868 Hayward Fault earthquake were to reoccur today, more than five million people would be affected and total property damage would likely exceed $165 billion. When the Hayward quake does hit, roads will be closed and underground gas and electricity lines will be cut, as well as many forms of communication.
"The Hayward Fault has the single highest probability of producing a large, damaging earthquake in the next decade (in the Bay Area)," San Francisco State associate professor of geosciences John Caskey said.
The chance of an earthquake in the Bay Area within the next 30 years is predicted to be a 62 percent possibility, with values varying by fault, San Francisco State geology professor Raymond Pestrong said.
The likelihood of a quake on the Hayward and San Andreas faults are 27 and 23 percent, he said.
Although the college's proximity to the faults may seem frightening, most of the buildings on campus are in condition to withstand the projected 6.7-7.0 magnitude Hayward quake or are scheduled to undergo construction to be in such a condition soon, Buildings and Grounds Manager Bruce King said.
Many of the results verifying this conclusion were determined by a process called seismic trenching., he said. During trenching, surveyors dig a roughly 20-foot hole in a specific region near the fault to survey soil and ultimately determine future fault activity in that particular area.
Geologists have carried out seismic trenching near the SA Building, behind the Humanities Building, near the tennis courts and by the concession stand, King said.
As a result of this testing, the college was given the OK to rebuild the SA Building within the fault region just slightly farther toward the H Building, given that it fits seismic safety standards, King said. Also in the fault zone, the SSC was approved before its construction in 2007.
"As we take down a building, we build a new one up to code," college President McKinley Williams said.
Yet, amid all this construction, some buildings are still surviving on patchwork until the future construction detailed in the Master Plan is executed, King said.
Buildings and Grounds has had to patch cracks caused by fault shifting in both the Art and Biological Sciences buildings, he said.
As a part of the Master Plan, King said all of the buildings will be built up to code and away from areas that put the buildings at greater risk. Construction planners have avoided placing any buildings directly on the Hayward Fault line, consistent with the closing of neighboring El Portal Elementary School because of its situation on top of the fault, he said.
Seeking to prepare CCC for the occasion of an earthquake, management on campus has listened to geologists and seismic surveyors and is working to make the campus as earthquake safe as possible, King said.
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