Quake swarm near the California-Mexico border gets scientists’ attention

More than 250 small earthquakes have struck since New Year’s Eve near the California-Mexico border, causing unease among residents and attention from scientists. The strongest earthquake in the sequence was magnitude 3.9, directly underneath Brawley, about 170 miles southeast of Los Angeles. The earthquakes struck in the southern end of the Brawley Seismic Zone, a seismically…