A new study reports that Southern California’s San Andreas Fault system and the neighboring San Jacinto Fault are under the highest tectonic stress levels seen in about the past 1,000 years. Researchers describe the faults as being in a “critically loaded” state, meaning stress on multiple fault segments is at or above the highest values in the millennium-long record they examined.
The study also finds that the two fault systems are closely linked and that rupture on one fault could potentially propagate to the other. Several outlets cite the possibility that a through-going rupture could involve both fault systems and affect a wide region.
ScienceDaily highlights a specific area where the faults meet near the Cajon Pass, describing it as an “earthquake gate” that may influence whether future rupture spreads across both faults. Other coverage emphasizes that the combination of elevated stress and fault interconnection increases the chance of a large earthquake occurring in the future, though the study does not assert a specific timing.
The findings were published in the Journal of Geophysical Research: Solid Earth, according to multiple reports.
