4.5 quake hits Puerto Rico amid rare seismic activity

A 4.5-magnitude earthquake hit Puerto Rico on Thursday in the latest of a rare string of quakes that has frightened many in the U.S. territory.The most recent quake occurred eight miles (12 kilometers) south of Guayanilla at a shallow depth of four miles (seven kilometers) and was felt in the capital of San Juan and elsewhere in Puerto Rico, according to the U.S. Geological Survey.The flurry of quakes began the night of Dec. 28, with a 4.7-magnitude quake followed by a 5.1-magnitude one that hit