Study Finds San Andreas and San Jacinto Fault Stress Levels Highest in 1,000 Years
A new AGU Journal study finds tectonic stress beneath two major Southern California faults at its highest level in a millennium. Researchers used geological records and simulations to map stress buildup at their convergence near Cajon Pass.
nypost.comStress levels beneath the San Andreas and San Jacinto fault systems have reached their highest point in at least 1,000 years, according to a study published in AGU Journal. Researchers reconstructed roughly 1,000 years of earthquake activity using geological evidence, radiocarbon dating, historical records, and computer simulations that track how stress accumulates and transfers between faults.
The study shows stress levels on the two faults have become more similar to each other.
This convergence occurs at Cajon Pass, northeast of Los Angeles, where the faults meet and which researchers call an “earthquake gate” that can determine whether a rupture stays on one fault or spreads to others. A rupture beginning on one fault could affect communities from Los Angeles to San Bernardino, Riverside, and the Coachella Valley.
The model indicates conditions now favor the possibility of a large earthquake jumping between the two systems.
9 Fort Tejon earthquake struck the San Andreas Fault. That event remains one of the strongest in California’s recorded history. Southern California’s population and infrastructure are substantially larger today than they were at the time of that quake.
Scientists cannot predict when a major earthquake will occur. The study states that geological conditions for a potentially catastrophic event are becoming more noticeable.
