Tsunami Simulation of the M6.4 7 January 2020 of Southwestern Puerto Rico

Session: Early Results from the 2020 M6.4 Indios, Puerto Rico Earthquake Sequence [Poster]
Type: Poster
Date: 4/30/2020
Time: 08:00 AM
Room: Ballroom
Description: 

An earthquake of magnitude Mw 6.4 shook the island of Puerto Rico during the early hours of January 7, 2020. The focus of this earthquake occurred at a depth of 6 km at 17.9578N, -66.8113E, near the southwestern coast of the island. The seismic event belongs to a seismic sequence that began on December 28, 2019 with an earthquake of magnitude Mw 4.7 in the fault system that crosses the Lajas Valley. Faults involved in this seismic sequence are the Punta Montalva and Guayanilla Canyon Faults. No evident surface rupture has been observed on-land, since the epicenter occurred mostly at sea. The USGS National Earthquake Information Center computed a moment tensor showing a normal focal mechanism, with either a NW or SE dipping plane. The vertical-normal displacement of the earthquake of January 7, 2020 generated a small tsunami between 2 – 5 cm high that was registered at the Parguera tide station in Magueyes Island, 10 minutes after the origin time and at the tide station located in Esperanza in Vieques Island 18 minutes after the event. Although it is known that the tsunami was caused by the vertical-normal displacement of the earthquake, it is uncertain which of the two dipping planes was responsible for the observed displacement. This study uses the published NEIC focal mechanism to simulate hypothetical tsunamis using each nodal plane as source to compare the results obtained with those observed. However, the fact that the rupture process has occurred in several faults can create errors in the estimation of the tsunami based on a simplified mechanism used here.

Presenting Author: Hiriagnny A. Lorenzo Paulino

Authors