Study Finds Highest Stress in 1,000 Years on San Andreas and San Jacinto Faults at Cajon Pass
A new study finds stress levels on two major California faults at their highest point since at least 1000 AD. Researchers used geological records and simulations to track stress buildup at their junction near Los Angeles.
news.sky.comStress levels on California’s San Andreas and San Jacinto faults 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 on the two faults 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 San Andreas and San Jacinto faults have become more similar to each other.
The convergence occurs at Cajon Pass, northeast of Los Angeles, where the faults meet. Researchers refer to Cajon Pass as 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 San Andreas and San Jacinto fault systems. The 1857 Fort Tejon earthquake struck the San Andreas Fault and 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.
