Fault Line Between L.A. And San Diego Could Produce 7.4 Quake, Says New Study

A fault line that runs through L.A., Orange, and San Diego counties could set off a 7.4 magnitude quake, says a new study.

The fault system includes the Newport-Inglewood fault in L.A. and Orange counties, and the adjacent Rose Canyon fault, which runs down to San Diego, reports the L.A. Times. For three decades, some scientists had assumed that the two faults were actually one continuous line, but this was hard to prove, as the gap between the two systems was located beneath the Pacific Ocean between Newport Beach and La Jolla. In the latest study, researchers went aboard ships that were equipped with machines that sent out acoustic waves.

After drawing up a map of what was underneath, researchers found proof of what they'd suspected for years; the gap between the two systems was only 1 1/4 miles apart from each other, not 3 miles, as reported in the past. Though the fault systems are largely offshore, they're never more than 4 miles away from the shore, reports the OC Register.

In the event of the theoretical 7.4 quake, both the the Newport-Inglewood and Rose Canyon faults would have to rupture. Now, with new reports of how close the systems are, that doesn't seem like such a far-fetched possibility.

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As noted at the OC Register, a 7.4 quake would be more drastic than any quake that has hit the region in recent times. The 1994 Northridge quake was a magnitude of 6.7. The last quake on the Newport/Rose fault was a 6.4 magnitude temblor that occurred in Long Beach; it resulted in 115 deaths.