New California earthquake analysis suggests damage could be double previous estimates

A single large earthquake along the San Andreas Fault line could rupture simultaneously in both Northern and Southern California potentially causing 126 percent more residential property damage than previously thought, according to data analysis from CoreLogic.

This would place more homes at risk and increase loss estimates in a state already at high risk for earthquake damage.

Ruptures on the north and south of the San Andreas Fault had previously been viewed as mutually exclusive of one another.

An earthquake of magnitude 8.0 or higher will affect a larger land area and greater number of people should an earthquake happen simultaneously on the northern and southern San Andreas faults.

CoreLogic has produced an earthquake risk analysis that illustrates the higher conditional probability of losses for an earthquake impacting both regions simultaneously.

The risk analysis is based on four earthquake scenarios and the resulting increase in both the number of single-family homes that could be damaged and the accompanying reconstruction cost value (RCV).

A magnitude 8.3 earthquake along the San Andreas Fault could result in a full rupture and increase the number of homes damaged by 126 percent, from 1.6 million to 3.5 million homes, and increase RCV by 79 percent, from $161 billion to $289 billion.

Another scenario that expands earthquake risk from just the southern San Andreas Fault to a full rupture increases the number of homes damaged by 54 percent, from 2.3 million to 3.5 million, and increases RCV by 111 percent, from $137 billion to $289 billion.

A magnitude 8.2 or 8.0 earthquake scenario would still impact regions of the fault and much of the geography of the state, as well as increase the number of homes damaged and the RCV, according to CoreLogic.