Major earthquake could cause Orange County area to drop several feet, experts say

SEAL BEACH, Calif. (KABC) -- Experts on Tuesday said there are new concerns a major earthquake could cause the ground to sink several feet in one area of Southern California.

Many residents of Seal Beach say they know the chance of a big earthquake always exists in the Southland. But what if it wasn't just shaking, but quick and violent sinking?

California State University, Fullerton professor Matt Kirby was part of a research project that started after the 2004 tsunami in Thailand. They were all wondering whether one has ever happened in Southern California.

Participants in the project tested the soil in wetlands on the Naval Weapons Station Seal Beach. Their results showed strange layers of sediment consistent with the sudden sinking of a 5 square kilometer stretch of land on the base.

"At first, I didn't believe it," shared Kirby.

Officials said in an event of a major earthquake, areas such as an elevated concrete walkway would drop down to ground level instantaneously.

"You would then have water start spilling in to fill in that basin because you essentially made your bathtub deeper, so to speak. It would not be a pleasant experience at all," Kirby said.

He added that it's possible with a magnitude 7.0 or greater earthquake on the Newport-Inglewood fault.

"Every place has something you have to deal with," said Seal Beach resident Rick Sharp. "You know, we don't have to deal with forest fires out here...but we do have earthquake faults."