San Diego – A recent study of the Institution of Oceanography at the University of California San Diego (UCSD) shows that there is a significant fault between San Diego and Los Angeles that could be the cause of a magnitude 7.4 earthquake in California.
This study looked the Rose Canyon fault and the Newport-Inglewood fault and concluded that they are not separate fault systems, but they actually are an only and continuous fault that runs from San Diego Bay to Los Angeles.
For the examination, they collected data from activity between 2006 and 2009, and they added to that information a bathymetric data from those years and scripts from 2013. With this information, they defined the fault dimensions and magnitude with more precision than other studies before.
The study was published on Tuesday, and it exposes that the fault extends to the northwest from La Jolla Canyon to Newport Beach, and then it parallels the coast from Newport Beach to Seal Beach and continues into the Los Angeles Basin.
“This system is mostly offshore but never more than four miles from the San Diego, Orange County, and Los Angeles County coast. Even if you have a high 5 or 6 magnitude earthquake, it can still have a major impact on those regions, which are some of the most densely populated in California,” said Valerie Shakian, lead author of the study, according to International Business Times.
The most recent event on this fault zone was the Long Beach earthquake in 1933, with a magnitude of 6.4. It occurred because of a rupture on the northern end of this fault zone. Records show that the rupture in that opportunity was near Newport Beach, and it propagated to the north.
Methods used and possibles scenarios
According to the 53 pages study, researchers used two methods to reach these conclusions about the possibility of a big earthquake in California. Those methods were the seismic reflection data and the Coulomb stress modeling. The last method consists in conducting the models for each fault to develop a mathematical understanding of the potential for through-going rupture across fault stepovers.
In the experiments, they studied three possibles scenarios: the first one investigates the effects from a rupture con La Jolla on strands to the north. The second scenario was a rupture on the Carlsbad Canyon and effects strand to north and south. Finally, the third scenario studied was a rupture on the Camp Pendleton splay.
After all these studies, researchers could determine that California may be in danger if the offshore or southern onshore segments rupture.
Source: Journal of Geophysical Research