According to CBS San Francisco, experts have long debated whether the Hayward Fault (which runs from the San Pablo Bay to San Jose) and the Rodgers Creek Fault (which runs from the San Pablo Bay to Healdsburg) were connected, but now there’s strong evidence that they are. Together, the two faults run more than 90 miles across the Bay Area.
US Geological geophysicist Janet Watt made the discovery in an underwater survey over the San Pablo Bay. “We now have direct evidence that the faults come closer together in the bay and may be directly connected,” says Watt. “It would be devastating for an earthquake to rupture at both those faults — it’d be a very strong earthquake.”
The two fault lines could potentially trigger a 7.3 magnitude earthquake if they ruptured together. That’s stronger than the 6.8 magnitude 1989 Loma Prieta quake, and considering that the Hayward Fault is the most inhabited fault on the planet, a 7.3 magnitude quake could be catastrophic. Yikes.