New Study Looks at Impact of Rose Canyon Fault Earthquake

A magnitude 6.9 earthquake on the Rose Canyon Fault in San Diego could damage 100,000 houses, result in prevalent road and bridge failures and cause parts of Mission Bay to sink about a foot.

According to a report by the San Diego chapter of the Earthquake Engineering Research Institute, such an earthquake could also cut gas and water service between La Jolla and the Silver Strand for months, collapse major municipal buildings, and close the San Diego-Coronado Bridge.

The unveiling of an updated San Diego Earthquake Scenario took place at the Sheraton Harbor Island.

EERI Executive Director Heidi Tremayne said the Rose Canyon Fault was the focus of their study because it runs through the urban core of San Diego.

The Rose Canyon Fault threatens the civic and financial center of California's second-largest city and the nation's fourth-biggest naval base, possibly causing liquefaction and landslides.

It could damage 120,000 of San Diego County's 700,000 structures and cause $38 billion in economic losses from just building and infrastructure damage and $5.2 billion in lost income from business interruptions.

In the study released Wednesday by the Earthquake Engineering Research Institute, San Diego County faces an 18% probability of a temblor over the next 30 years along the fault, which stretches from La Jolla through downtown San Diego and across Coronado.

The quake centered off Del Mar could potentially kill 800 people, likely close Interstate 5 and the Coronado Bridge, cut many utility lines and displace 36,000 households.

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According to Jorge Meneses, president of the San Diego EERI, "Whatever happens to San Diego is going to affect Tijuana. And whatever happens to Tijuana is going to affect San Diego. So there should be a coordinated response after the earthquake."

The executive director of the EERI Heidi Tremayne said, "We're expecting a large fault rupture, almost six feet, a lot of liquefaction impacts, which basically is softening of the soil that causes a lot of impact to underground infrastructure like water distribution pipes."

"We're worried that coastal communities could really be lacking some basic services for many months after an earthquake of this magnitude."

Most people in San Diego either know nothing about the Rose Canyon fault or think it is dormant, even though it has been 30 years since experts confirmed it is active. Meneses said this type of mentality needs to change.

Older and more vulnerable buildings, such as the key City of San Diego buildings could be severely damaged and undergo partial to total collapse.

Loss of water pressure to certain communities could affect response to any fires.

Researchers of the study said that San Diego's infrastructure, homes, and businesses were not built to withstand the impacts of a major earthquake.

In the executive summary, they wrote, "The Rose Canyon Fault Zone strikes through the heart of the San Diego metropolitan area, presenting a major seismic hazard to the San Diego region, one of the fastest-growing population centers in California and home to over 3.3 million residents."