A swarm of earthquakes has hit the Imperial Valley city of Brawley, the most significant ranging in magnitude from 2 to 4.7 — with scores more registering at lower magnitudes. In all, the U.S. Geological Survey has reported some 355 quakes over the past day. At least 40 quakes strong enough to make the 2.0 and higher magnitude list are among those.

Since the U.S. Geological survey upgraded its earthquake monitors in northwest Louisiana, its earthquake map is showing much smaller quakes than previously. The area has been of interest to seismologists since a historically-large quake in March.

A 3.4-magnitude earthquake struck roughly 4 miles southwest of Redlands near the border of Riverside and San Bernardino counties Friday evening. The earthquake is the third sizable quake to hit the Inland Empire this week.

Scientists triggered 8,000 small earthquakes in Switzerland’s BedrettoLab to study how seismic pressure builds and how deep earthquakes begin underground.

More than a dozen earthquakes shook Brawley, Calif. Saturday night, including a 4.4-magnitude quake that was felt across Southern California’s inland area. The quakes come a day after a