The volatile seismic zone along the roughly 750-mile (1,200-km) San Andreas Fault and the smaller San Jacinto Fault are now "critically stressed" – reaching a 1,000-year high level of pressure – increasing the likelihood of a big earthquake hitting the US West Coast.

The volatile seismic zone along the roughly 750-mile (1,200-km) San Andreas Fault and the smaller San Jacinto Fault are now “critically stressed” – reaching a 1,000-year high level of pressure – increasing the likelihood of a big earthquake hitting the US West Coast.