San Andreas fault line could cause greater earthquakes than first thought, researchers say

The central section of the fault line has not had a major earthquake in 2,000 years, but that doesn’t mean it can’t produce one

Graig Graziosi
Monday 28 February 2022 21:45
Comments

Related video: Earthquake felt near LA

The San Andreas fault line in California may be capable of producing much larger earthquakes than previously believed.

The findings were published in the journal Geology, and found that earlier assumptions about the scale of possible earthquakes produced by the fault line were underestimates.

According to the research, scientists previously believed that a central section of the fault produced less severe earthquakes than other sections of the fault. However, the study's authors concluded that large magnitude earthquakes are possible in the area and have happened in the past.

The San Andreas Fault is an 800-mile stretch through California where the Pacific and North American tectonic plates meet. The fault runs from north of San Francisco to San Diego.

Researchers previously believed that the largest earthquakes were formed at the ends of the fault, where immense pressure can build over time, releasing in major quakes.

California regularly experiences earthquakes, with southern California logging 10,000 each year. Most of these are minor quakes that are imperceptible to residents of the state. Only about 15 to 20 in the area are greater than a 4.0 each year.

However, major earthquakes have happened, like, the 7.9 magnitude quake that hit San Francisco in 1906, which killed more than 3,000 people. Another 57 people died in 1994 after a 6.7 magnitude quake occurred near Los Angeles.

According to the researchers, the central section of the fault line, which runs through the central coastal region of California, has not had a major earthquake in 2,000 years. However, they found that larger earthquakes had happened in the distant past.

The scientists' analysis determined that rocks in the central fault section had been moved more than five feet, largely due to earthquakes in that region. That equates to earthquakes of a 6.9 magnitude in the past.

"Ultimately, our work points to the potential for higher magnitude earthquakes in central California and highlights the importance of including the central [San Andreas Fault] and other creeping faults in seismic hazard analysis," the study concluded.

Dr Genevieve Coffey, the lead author on the study and an earthquake geologist at Columbia University's Lamont-Doherty Earth Observatory, told Columbia Climate School news that the findings should alert other researchers to the potential for large earthquaks originating in the region.

"We should be aware that there is this potential, that it is not always just continuous creep," she said.

Register for free to continue reading

Registration is a free and easy way to support our truly independent journalism

By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists

Please enter a valid email
Please enter a valid email
Must be at least 6 characters, include an upper and lower case character and a number
Must be at least 6 characters, include an upper and lower case character and a number
Must be at least 6 characters, include an upper and lower case character and a number
Please enter your first name
Special characters aren’t allowed
Please enter a name between 1 and 40 characters
Please enter your last name
Special characters aren’t allowed
Please enter a name between 1 and 40 characters
You must be over 18 years old to register
You must be over 18 years old to register
Opt-out-policy
You can opt-out at any time by signing in to your account to manage your preferences. Each email has a link to unsubscribe.

By clicking ‘Create my account’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Already have an account? sign in

By clicking ‘Register’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Register for free to continue reading

Registration is a free and easy way to support our truly independent journalism

By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists

Already have an account? sign in

By clicking ‘Register’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Join our new commenting forum

Join thought-provoking conversations, follow other Independent readers and see their replies

Comments

Thank you for registering

Please refresh the page or navigate to another page on the site to be automatically logged inPlease refresh your browser to be logged in