Two Major Fault Lines Could Lead to Major Earthquake in California

Two Major Fault Lines Could Lead to Major Earthquake in California

Geologists have found two major fault lines in Bay Area which could trigger a strong earthquake in California. Both the fault lines are connected to each other and if they rupture simultaneously, they could lead to devastating earthquake in California, geologists warn. There are many earthquake faults in the Bay Area but in most of the cases, they lead to low intensity seismic activity. These two earthquake faults are closely linked and they could combine their force for the next major seismic event in California.

It is difficult to collect high-resolution maps for the Bay Area region due to shallow waters and presence of gas in bay sediments. Earlier, geologists estimated nearly 3 miles distance between the faults. But, after conducting a detailed review of the Hayward and Rodgers Creek faults, researchers estimate that they could lead to 7.4 magnitude earthquake. The Hayward fault runs under neighborhoods east of San Francisco, a region that is densely populated.

The Rodgers Creek fracture runs 56 miles north of the bay. The Hayward fault has not witnessed any major earthquake over the last 140 years. The Hayward fault passes through Berkeley and Oakland. The fault extends for 62 miles from San Jose to San Pablo Bay.

Study lead author Janet Watt, a geophysicist at the U.S. Geological Survey, said, "We drove back and forth across the Bay — very unexciting when you're in the field. The size of an earthquake that can occur on a fault depends on how long that fault is. So when we have two faults that are directly connected instead of separate fault segments, it makes a longer fault, and there is a possibility of a larger earthquake."

The results of the current study were published in the journal Science Advances.

A report by Associated Press said, "The underwater surveys revealed a previously unknown strand of the Hayward Fault that connects to the western section of the Rodgers Creek Fault. One reason why it has taken so long to determine the relationship between the two faults is because the bay is very shallow, which makes it hard to use a boat. Researchers floated instruments on pontoons."

A report published by Live Science informed...

Watt said that the researchers will next look at how often in the past these faults have ruptured together. By looking at previous activity, the team could determine the area's current seismic hazard and estimate the risk of future quakes.

"We always need reminders that earthquakes occur, because they can happen so infrequently," Watt said. "And we need to be prepared for something stronger than the Lomo Prieta."