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[I]t appears these two quakes may have occurred on two separate faults. Several faults intersect in this tectonically complex region. Historically, when experts evaluate earthquake risk, they haven't necessarily accounted for this multifault scenario, says Chris Goldfinger, a paleoseismologist at Oregon State University. "We always tend to kind of assume that earthquakes will just be on one fault and only on one fault," he says. In 2016, a multifault event — the Kaikōura earthquake in New Zealand — took people by surprise, says Goldfinger, and changed scientists' understanding of how interconnected faults can trigger multiple ruptures. Assuming the Venezuelan quakes...

This has scientists quaking in their boots. Researchers have found that one of the US’s most dangerous fault lines is overdue for an earthquake, potentially threatening millions of people across California, per an alarming study in the journal Seismological Research Letters. This terrifying tremor could “cause extensive damage to such a dense population zone,” wrote the team from the Lawrence Livermore National Laboratory (LLNL) and Lawrence Berkeley National Laboratory (LBNL), in a statement. Part of the massive San Andreas Fault Line, the Hayward Fault Line extends 74 miles through major Bay Area hubs, including Berkeley, Oakland and Fremont, an area...

When a catastrophic earthquake hits California, buildings will topple and potentially hundreds could be killed. But what gets less attention is the wrenching aftermath of such a huge temblor, which could leave whole neighborhoods torched by fires uninhabitable and hundreds of thousands of people without a home. Officials are grappling with where all these quake refugees would go. In the San Francisco Bay Area, more than 400,000 could be displaced in a magnitude 7 earthquake on the Hayward fault, which directly runs underneath cities like Berkeley, Oakland, Hayward and Fremont, said Ken Hudnut, the U.S. Geological Survey’s science advisor for...

In the San Francisco Bay Area, more than 400,000 could be displaced in a magnitude 7 earthquake on the Hayward fault, which directly runs underneath cities like Berkeley, Oakland, Hayward and Fremont, said Ken Hudnut, the U.S. Geological Survey’s science advisor for risk reduction. And it’s possible that more than 250,000 people in Southern California could be forced out of their homes after a major earthquake on the San Andreas fault, Hudnut said. Not everyone will need to stay in public shelters — many will stay with relatives, friends and hotels. Still, more than 175,000 people may have no other...

A magnitude 4.0 earthquake was reported Monday morning in Piedmont, Calif., near Oakland, according to the U.S. Geological Survey.

Earthquake on Hayward fault. I'm in San Francisco. Seemed stronger than 4.2 from that distance.

(CBS SF) — The fault that produced a 4.0-magnitude earthquake in Fremont early Tuesday morning is expected to produce a major earthquake “any day now” and Bay Area residents should be prepared, a U.S. Geological Survey scientist said. The 2:41 a.m. earthquake on the border of Fremont and Union City occurred on the Hayward Fault at a depth of 5 miles. The epicenter was at a spot just north of the intersection of Niles Canyon Road and Mission Boulevard. The quake caused some BART delays early today while work crews checked the tracks, but appears to have caused no major...

With several faults slicing through the San Francisco Bay Area, forecasting the next deadly earthquake becomes a question of when and where, not if. Now researchers propose that four faults have built up enough seismic strain (stored energy) to unleash destructive earthquakes, according to a study published today (Oct. 13) in the Bulletin of the Seismological Society of America. The quartet includes the Hayward Fault, the Rodgers Creek Fault, the Green Valley Fault and the Calaveras Fault. While all are smaller pieces of California's San Andreas Fault system, which is more than 800 miles (1,300 kilometers) long, the four faults...