Recent storms may have ended California’s drought when it comes to water, but not when it comes to quakes, according to scientists. The state is in the midst of an earthquake drought.
Seismologists are saying there haven’t been enough powerful earthquakes in the past 100 years along California’s highest slip-rate faults, and a ground-rupturing quake with a magnitude greater than 7.0 is overdue, CBS SF Bay Area reports.
A new study coming out Wednesday in the Seismological Research Letters says California’s current earthquake drought is unlike any other paleoseismic period in the last 1,000 years. The aim of the study, titled, “The Current Unlikely Hiatus at California’s Transform Boundary Paleoseismic Sites,” points to the unlikelihood of the last hundred years of relative seismic silence.
Researchers at the U.S. Geological Survey analyzed data from the San Andreas, San Jacinto, Elsinore and Hayward faults as well as identified eight ground-rupturing quakes between 1800 and 1918. Those include a devastating quake in 1906 in San Francisco with an estimated magnitude of 7.9, and a similar earthquake in 1857 in Southern California.
There have been no quakes comparable in size since 1918, and the study says the current hiatus is “exceptional.”
“If our work is correct, the next century isn’t going to be like the last one, but could be more like the century that ended in 1918,” said lead researcher Glenn Biasi. “We know these big faults have to carry most of the [tectonic] motion in California, and sooner or later they have to slip. The only questions are how they’re going to let go and when.”
Since the earthquake of 1906 destroyed much of San Francisco, there have been only three quakes magnitude six or higher, including Loma Prieta in 1989, CBS Sacramento reports. But in the 1800s, there were 14 big quakes.
The Hayward fault, which runs through most of the East Bay, concerns Angela Chung at the the University of California, Berkeley’s Seismology Lab. It’s one reason she helped develop an alert system that sends warnings to your cellphone. It was tested in Oakland last week.
“We can’t predict earthquakes what we can do is let you know when quake strikes, you’re about to feel the shaking,” she said.
Berkeley structural Engineer Thor Matteson, is seeing a six-month backlog of people wanting to seismically retrofit their houses. “What we’re looking to do is keep you in your house and out of tent city,” said Matteson.
Experts urge everyone to be quake ready.