Southern California is famous for its sandy beaches, wine country, theme parks and Hollywood glitz. And also its earthquakes. Now, researchers have identified more than 1.8 million previously unknown earthquakes that hit Southern California between 2008 and 2017. The findings suggest these truly tiny earthquakes — as small as just 0.3 magnitude on the Richter scale — happen every 174 seconds, yet they’re hardly felt on Earth’s surface.

“The goal was to produce a state of the art earthquak