Post-Seismic Relaxation of 2020 Southwestern Puerto Rico Seismic Complex From New Gnss Network
Description:
The Southwest Puerto Rico Mw 6.4 earthquake that occurred on January 7th, 2020 is the most significant event affecting the island of Puerto Rico since the Mw 7.2 earthquake that occurred on October 11th, 1918. Three years monitoring seismicity in the epicentral region has culminated with the conclusion that a complex fault system and processes associated to the interaction of separate crustal blocks within the Puerto Rico–Virgin Islands microplate were primarily responsible for this event. In this study, we present a qualitative analysis of the post-seismic relaxation behavior of southwestern Puerto Rico (SWPR) fault complex with post-seismic deformation using GNSS stations from a new continuously operated GNSS network funded by the NSF RAPID program and installed by the Puerto Rico Seismic Network (PRSN) in late 2020 and early 2021. Our methodology included data acquisition and data processing of GNSS data from UNAVCO GAGE Facility and the use of GIPSY-OASIS II (v6.4) software along with final orbit, clock, and earth orientation parameters from JPL to calculate daily, absolute point position estimates in ITRF14, and then we removed Caribbean plate motion. Observations of velocity vectors from processed GNSS data were made in order to quantify tectonic displacement since site installation and infer the amount of post-seismic relaxation. Our preliminary data indicated parts of the SWPR block are returning to its inter-seismic motion towards the northwest, while other sites, particularly those near the Punta Montalva Fault, reflected that some after-slip or relaxation is still ongoing. Future data analysis using the newly installed GNSS network will be improved with an increased time of data acquisition resulting in more precise constraints on the motion of the SWPR block relative to the larger Puerto Rico-Virgin Islands block to the north and the Caribbean plate to the south.
Session: The 2020-2021 Southwest Puerto Rico Seismic Sequence: Current State of Knowledge and Implications [Poster]
Type: Poster
Date: 4/18/2023
Presentation Time: 08:00 AM (local time)
Presenting Author: Chris Justiniano
Student Presenter: Yes
Invited Presentation:
Authors
Chris Justiniano Presenting Author chris.justiniano@upr.edu University of Puerto Rico, Mayagüez |
Alberto López Corresponding Author alberto.lopez3@upr.edu University of Puerto Rico, Mayagüez |
Glen Mattioli glen.mattioli@earthscope.org University of Texas at Arlington |
Pamela Jansma pamela.jansma@ucdenver.edu University of Denver |
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Post-Seismic Relaxation of 2020 Southwestern Puerto Rico Seismic Complex From New Gnss Network
Category
The 2020-2021 Southwest Puerto Rico Seismic Sequence: Current State of Knowledge and Implications