California earthquake risk increases in new seismic forecast

Seismologists have released the third Uniform California Earthquake Rupture Forecast, which indicates an increased probability of a major earthquake striking the Bay Area within the next 30 years. The chance of a magnitude 6.7 or stronger earthquake hitting the region has risen to 74.1%, a 2.1% increase from a decade ago. Experts attribute this rise to the accumulation of tectonic stress during the period since the last major ruptures.

The San Andreas Fault saw its 30-year rupture probability increase by 3.6%, reaching 25.5%. Meanwhile, the Hayward-Rodgers Creek fault system, which runs beneath densely populated East Bay communities, carries a 34.3% probability of rupturing. Scientists noted that a linked rupture between these two systems could potentially generate a magnitude 7.4 earthquake.

In Southern California, tectonic-plate loading along the San Andreas and San Jacinto fault systems has reached its highest level in approximately 1,000 years. Researchers have identified the Cajon Pass as a critical area of concern, describing it as a potential ‘earthquake gate’ that could either halt or facilitate the propagation of a large rupture.