BERKELEY -- Historian Richard Schwartz is busy repeating his warning about the imminent danger of a disastrous earthquake in the East Bay.
Schwartz, who is also a building contractor, gave his latest warning Oct. 27 to a group of about 125 people at Spenger's Fish Grotto. He based his forecast on his own research, including information from the United States Geological Survey.
"USGS scientists describe this fault as a tectonic time bomb, due anytime for another magnitude 6.8 to 7.0 earthquake," according to a USGS fact sheet.
Chris Wills, a geologist with the California Geological Survey, agreed.
"There is a 31 percent chance of a magnitude-6.7 earthquake or greater along the Rogers Creek-Hayward Fault in the next 30 years," Wills said.
If the Hayward Fault produces an earthquake, hundreds of people could lose their lives, according to the USGS.
Schwartz is hoping the people who attended the Berkeley presentation will tell others and more people will be prepared before the earthquake strikes. As a building contractor, Schwartz specializes in seismic retrofits.
But as a historian, Schwartz said he has a responsibility to tell others. Schwartz said he took six weeks to prepare for the talk. He is the author of several books, including "Earthquake Exodus, 1906," which describes the movement of people from San Francisco to Berkeley after the 1906 San Francisco earthquake.
The Earthquake Country Alliance suggests residents take seven steps to prepare for an earthquake:
According to the USGS fact sheet, two factors make "the Hayward Fault very dangerous." More than 2.4 million people now live near the fault, and hundreds of homes and other structures are built directly on the fault. The second factor is the increasing odds of a major earthquake along the fault. According to the USGS, the "most recent damaging earthquake" along the fault was 144 years ago.
USGS scientists have found evidence for 12 quakes on the southern Hayward Fault during the past 1,900 years. The last five events -- in 1315, 1470, 1630, 1725 and 1868 -- occurred at intervals of 95 to 160 years, with an average interval of 138 years.