A 4.5-magnitude earthquake shook northern Sonoma County at 12:34 p.m. on Saturday, according to the U.S. Geological Survey.
The epicenter was estimated at 5 miles west of Cobb, and 14.2 miles north of Healdsburg in the Mayacmas Mountains. It was about 4 miles north of The Geysers, the world’s largest steam field which includes 18 geothermal power plants and, as of 2019, generated about 20% of California’s renewable energy.
The USGS activated its Shake Alert system, delivering alerts to cell phone users around the area about the quake. The system just recently got an upgrade this week that sends earlier, more accurate estimates of the magnitude of an earthquake, even before the ground starts shaking, the LA Times reported.
