The US Geological Survey (USGS) has issued a report on the 112th-year anniversary of the San Francisco Earthquake warning that 7.0 quake on the San Andreas Fault’s big brother, called the Hayward Fault, could create a massive liquefaction event (sandy soils becoming liquid-like) along much of the East Bay periphery.
The Hayward Fault was named California’s “tectonic time bomb” in 2007 by seismologist Tom Brocher, due to the growing risk for 2 million Bay Area people that live above it.
The USGS estimates a main-shock collapse of 2,500 buildings, 800 killed people and 18,000 severe injuries. People stuck in elevators could also die over the following days. Emergency workers would be overwhelmed with more than 22,000 people requiring rescue from stalled elevators.
With water mains broken, secondary shock would include about 400 natural gas fires erupting and potentially destroying 52,000 homes. About 152,000 households would be displaced due to damage or lack of access, causing approximately 411,000 people to be displaced. The estimated total financial loss would be about $82 billion.
The buildup of pressure along the northern San Andreas fault in the 1800s produced a series of magnitude 6.0 or greater earthquakes, eventually leading to the 1906 magnitude 7.8 San Francisco Earthquake. But California’s 1868 magnitude 7-plus quake along the 75-mile Hayward Fault may have been largest and potentially deadliest quake, had more people been living in the area..
The U.S. Geological Survey led a collaborative effort with United Research Services, Lawrence Livermore National Laboratory, Stanford University, and the University of California at Berkeley created computer simulations in 2008 for anticipated earthquakes on the Hayward fault.
Researchers are concerned that the last large quake along the Hayward Fault was in October 1868. Scientists have documented 12 major prehistoric earthquakes along the fault over the past 1,900 years that re-occur in about 150-year intervals, which means the clock is ticking.
Researchers are especially concerned that the Hayward Fault’s 45-mile long little sister the Rodgers Creek Fault, which runs from Santa Rosa south to just north of Richmond in San Pablo Bay, could combine in an epic cascading 130-mile long monster earthquake.
USGS earthquake geologist emeritus David Schwartz commented to the Los Angeles Times regarding the risk of a 7.0 magnitude eruption along the Hayward Fault, “It’s just waiting to go off.”
The USGS offers an online information booklet published in several languages called “Putting Down Roots in Earthquake Country” that can serve as a guide to prepare for what experts believe is the inevitable large earthquake to strike the San Francisco Bay region.