A new study reveals that Cajon Pass, a mountain pass near Los Angeles, may act as an 'earthquake gate' influencing the spread of ruptures between the San Andreas and San Jacinto faults. - Researchers reconstructed 1,000 years of seismic history using geological and historical data.
- Stress levels on both fault systems are currently at a millennium high, a condition historically linked to multi-fault earthquakes. - The study does not predict a specific quake but offers a new risk assessment framework.
The findings highlight that the pass could determine whether a rupture remains isolated or cascades into a larger event, providing a fresh perspective on Southern California's seismic hazards.