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Palos Verdes fault running along coast of LA, OC could trigger devastating earthquake

A new study from Harvard University suggests that the Palos Verdes fault, running along the coasts of Los Angeles and Orange Counties, could trigger a devastating earthquake of up to 7.8 magnitude -- similar in scale to one that could be unleashed by the menacing San Andreas Fault. 

Though scientists have been aware of the fault's existence for years, the study declares that what they believe to be a new revelation could be the deciding factor in what unleashes "The Big One."

The Palos Verdes fault line runs directly underneath the Palos Verdes Peninsula, and though mostly underwater, it sits under places like Rancho Palos Verdes, Rolling Hills Estates and the Long Beach and Los Angeles Harbors. The nearly 70 mile line stretches from Dana Point to the Santa Monica Bay.

According to the study, the fault might actually be made up of an interconnected series of smaller faults, that could produce the massive quake, bigger than the deadly and destructive 6.7 magnitude earthquake that hit Northridge in 1997. 

"What this study did, was say we think these multiple strands can add up like they were individual strands and make it really long, and it's the length of the fault that determines how big a magnitude can be," said Dr. Lucy Jones, a well-known seismologist.

As she traditionally does in the moments after earth shaking news breaks, she eased the immediate concerns that came along with the announcement of the study's conclusion. 

"It is not in the hazard map. "This is two scientists that have said, 'This is the way we think it works,'" she said, noting that one factor people should take into account is the fault's slip rate, or how quickly the two sides of the fault are slipping relative to one another. "If it does have these earthquakes, they are infrequent, and this study didn't lower the slip rates at all one to 6 ml is a pretty big range."

The United States Geological Service will review the study and determine whether the to including it in the findings when they update the nation's hazard maps in 2025.

Hazard maps declare regions of concern, like those housing volcanoes or that are susceptible to earthquakes and landslides. The last update was in 2019. 

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