The 800-mile San Andreas Fault, which runs from northern California to Mexico, has been the source of the state’s biggest earthquakes. Known as the ‘sleeping giant’, it is one of more than 350 faults that are found across the state.
Scientists now predict that the risk of a mega quake in the next 30 years is higher than was previously thought.
The Third Uniform California Earthquake Rupture Forecast (UCERF3), published in March, includes newly discovered fault zones and accounts for the possibility of an earthquake jumping between them. This could result in multiple faults shaking in a simultaneous mega quake (magnitude-8), releasing enough energy to cause massive destruction.
The report says that, while there is a lower likelihood of moderate-sized earthquakes, the odds of a mega quake occurring in the next 30 years have increased from 4.7 per cent to 7 per cent.
Earthquakes are nothing new for Californians. The state experiences 1,000 quakes a year, but most are too small to be felt. While the San Andreas Fault has experienced massive earthquakes in the central and northern segments — Fort Tejon in 1857 and San Francisco in 1906 — the southern section has not had a large quake for more than 300 years. (Read more from “California Prepares for the Next ‘Big One'” HERE)