Close to 1,000 magnitude 2+ earthquakes send UM volunteers back from Puerto Rico

January 14, 2020
Due to a swarm of earthquakes, nine mission volunteers from Montana were advised to return from Puerto Rico after just landing last week. They were on a mission trip to help after the December 2019 earthquake. 

According to the United States Geological Survey (USGS), more than 1,000 earthquakes have affected Puerto Rico since December. A magnitude 5.9 earthquake southwest of Puerto Rico on Jan. 11 was the latest in a series of strong earthquakes in the same region over the past 2 weeks. This sequence began with a magnitude 4.7 earthquake late on Dec. 28 and a M 5.0 event a few hours later. The largest event in this sequence to date is a magnitude 6.4 earthquake on Jan. 7, which was preceded a day earlier by a magnitude 5.8 event.

Since the late December 2019, close to 1,000 magnitude 2+ earthquakes have occurred in this region (400 since the magnitude 6.4 on Jan. 7, the current mainshock), 50 of which were magnitude 4+ (39 since current mainshock), and eight of which were magnitude 5+ (5 since mainshock). The proximity of these events to Puerto Rico, and their shallow depth, mean that many of the M3 and above earthquakes have likely been felt on land.