SACRAMENTO, the United States, June 16 (Xinhua) -- Tectonic stress along Southern California's major fault systems, especially the San Andreas Fault and San Jacinto Fault, is now at or above levels seen over the past 1,000 years, according to a recent study published by the University of Hawaii at Manoa.
The study, published in the Journal of Geophysical Research: Solid Earth, examines how stress has accumulated and been released along fault segments in Southern California.
Researchers used physics-based simulations combined with a millennium-long record of past earthquakes to analyze how stress builds up and releases across fault segments. A key focus was Cajon Pass, a structural junction between the two fault systems that may sometimes block ruptures and other times allow them to link together.
The study said such a joint rupture could affect the greater Los Angeles area, San Bernardino, Riverside and the Coachella Valley. It also said a joint rupture could be more damaging than an event limited to one fault system.
However, the lead researcher emphasized that this is not a prediction of an imminent quake, but only an assessment of long-term stress conditions.
The U.S. Geological Survey also reiterates that while scientists can estimate long-term probabilities of major earthquakes, they cannot predict exact timing or location. ■