A magnitude 5.6 earthquake struck Northern California on Wednesday, marking the region’s strongest earthquake since 1940 and renewing attention to a recent study that found Southern California’s two largest fault systems are carrying the highest stress levels in at least 1,000 years.
The U.S. Geological Survey placed the epicenter about 7 miles northwest of Willits in Mendocino County. The quake struck at a depth of roughly 5 miles.
Officials said hospitals reported some injuries, but there were no immediate reports of major damage. More than 6,000 customers across six nearby communities briefly lost power, according to Mendocino County officials.
Study warns of elevated stress
The earthquake occurred just days after researchers published a study concluding the Southern San Andreas and San Jacinto fault systems are in a “critically loaded state” after centuries of accumulating stress.
Researchers used geological evidence, including sediment records and tree-ring data, to reconstruct how pressure has built over time. They stressed the findings do not predict when a major earthquake will occur, only that the faults are carrying unusually high levels of stored energy…