Late last week, an 8.2-magnitude earthquake shook Mexico City, killing more than 60 people and making it the largest earthquake to hit the city in the last century. Berkeley is situated directly on top of the Hayward Fault — could an earthquake comparable to Mexico City’s occur in Berkeley?
According to Jennifer Strauss, the external relations officer for the Berkeley Seismology Lab, it is unlikely that a similar earthquake would occur in Berkeley because the Hayward Fault is categorized as a strike-slip fault, which typically lead to milder earthquakes than that which was recorded in Mexico. The Hayward Fault can, however, reach an estimated maximum magnitude of 7.5, Strauss said.
The Mexico City earthquake caused severe damage because its epicenter was located in a subduction zone — a region in which plates of the earth’s crust slide, or subduct, under one another. The Berkeley area is not in a subduction zone and is therefore not susceptible to subduction-induced quakes like the one that occurred in Mexico.
Though not in a subduction zone, a maximum of 7.5 means that Berkeley could still experience a “severe” earthquake, according to the U.S. Geological Survey classification. The Hayward Fault runs directly under Memorial Stadium, and a tremor could damage buildings not seismically retrofitted.
Because of the threat, several buildings on campus have been retrofitted to withstand damage, including costly renovations of Memorial Stadium, Hearst Memorial Mining Building and McCone Hall, among others.
The seismic ratings of campus buildings are listed on the campus’s website, evaluated on a scale of “Implied Risk to Life” from negligible to dangerous. Of the buildings listed, 159 pose a “slight” risk to life, 53 a “small” and 59 a “serious” threat.
The most recent earthquake along the Hayward fault was of magnitude 6.8 and occurred in 1868 — the same year as UC Berkeley’s founding, according to Amina Assefa, manager of the campus Office of Emergency Management.
Assefa said the campus is focusing on the “larger message” of emergency preparedness and stresses personal responsibility in the event of an emergency. Assefa added that although the OEM will provide emergency services, it is best for individuals to prepare for themselves, especially if they have any special needs. “Be your own survivor,” she said.
The OEM has been on campus in some form since the late 1990s. Its most recent campaign and new website have been running for the past two years. The featured campaign “tap(s) into the survivor mentality,” according to Assefa, by delineating what should happen during and after an earthquake.
In anticipation of an emergency, Assefa encourages students, staff and faculty to download the emergency preparedness app and make a “go bag” with a few simple items for survival.
“Anywhere (in California) has the risk of earthquakes, so you need to have a plan (and) you need to be prepared,” Strauss said. “It’s a reality of living in California.”
Contact Anjali Shrivastava and Ella Jensen at [email protected].