Preliminary Shakemap Computation for the Indios M6.4 Earthquake, 7 January 2020, Puerto Rico

Session: Early Results from the 2020 M6.4 Indios, Puerto Rico Earthquake Sequence
Type: Oral
Date: 4/30/2020
Time: 11:15 AM
Room: 115
Description: 

A M4.7 earthquake on Dec. 28, 2019 started a series of multiple strong and damaging earthquakes in southern Puerto Rico, being the strongest a M6.4, 8 km south of the Indios ward of Guayanilla, Puerto Rico (Jan/07/2020). The main shock killed at least one person, caused many serious injuries and collapsed many structures, including a school in the town of Guánica that luckily was empty at the time of the earthquake. These are the most damaging earthquakes to strike Puerto Rico since 1918, leading the island to a declaration of emergency.

The ShakeMaps provide vital information within minutes after an earthquake to emergency response agencies, this sotware was developed by the USGS as a tool for near real time generation of ground shaking following an earthquake. The PR network (Puerto Rico Seismic Network/PRSN and the Puerto Rico Strong Motion Program/PRSMP) computed ShakeMaps based on (1) rapid earthquake location and size, (2) user DYFI/CIIM reports and (3) instrumental data from seismometers and accelerometers. The PRSN earthquake detection system is based on the EarthWorm modular package and rapid location and size estimation is done using the EarlyBird software. PR network operates more than 30 broadband and 50 strong motion real time stations. More than 80 additional strong motion stations are gradually added from the PRSMP for ShakeMap after field recovery. The site corrections are based on the local average shear-wave velocity values for the uppermost 30 meters (Vs30) and a combination between HAZUS generic GMPE’s and the Kanno regressions are used for computations.

In this abstract we will report on the final computation of the main shock ShakeMap after the incorporation of all available data, including the DYFI/CIIM reports collected by the USGS.

Presenting Author: Victor A. Huérfano

Authors