Rare Earthquake Swarm Strikes Puerto Rico

In Puerto Rico, however, “what we’re looking at here are earthquakes of more or less common size: There’s still lots of small ones but quite a few fives and then up to the 6.4,” said Jackie Caplan-Auerbach, a seismologist at Western Washington University in Bellingham. “That is a little more like what we would call an earthquake swarm, where there isn’t a clear dominant one early in the sequence and then a tapering.”