New GEER Report for January 2020 Puerto Rico Earthquake

An earthquake-induced landslide in Puerto Rico in 2020

The Geotechnical Extreme Events Reconnaissance (GEER) Association published their report last month on the January 7, 2020, Puerto Rico Earthquake. Here is the summary:

A seismic sequence located along the southwestern coast of Puerto Rico began on 28-December-2019 with a M 4.7 event. This foreshock was followed by an event of M 5.0 on the following day. On 6- January 2020 there was a M 5.8 event and then events of M 6.4 and M 5.6 on 7-January-2020 (Lopez et al., 2020a). The seismic sequence has included thousands of events with hundreds of these being felt by residents. Table 1 lists all events larger than M 4.5 from 28-December-2019 until 15-May-2020. The M 6.4 earthquake on 7-January-2020 is considered the “mainshock” for the sequence and triggered the most shaking throughout the southwestern region of Puerto Rico. Although the sequence began in 2019, we refer to it as the “2020” earthquake sequence because most of the events occurred after the new calendar year. Because there are a host of moderate to stronger earthquakes, with one definable main shock, the events together represent a sequence, rather than a swarm.

GEER Association

Download the report from the GEER Website.