Investigation of the earthquake (Michoacan-Colima) in Mexica (19.09.2022) by using GNSS stations and INSAR observations

Abstract

The North American Plate is subducted under the Cocos and Rivera plates, while the Pacific Plate divides from the North American Plate near the spreading centre of the Baja California Gulf, placing the Mexican Republic in a seismically active area of the world. The earthquake of a magnitude of Mw 7.6-7.7 occurred 37 km southeast of the town of Aquila (near the municipality of Coalcoman) at a depth of 15.1 km on 19.09.2022 at 18:05:06 UTC (13:05:06 local time (LT)). This study focuses on the use of GNSS (Global Navigation Satellite System) data to investigate the Mexican earthquake, and the results (using static-kinematic methods) are presented in this paper. The TNCC and COL2 IGS stations, which are situated to the north and northwest of the fault, recorded the largest displacements after GNSS data processing. At five points, 9-25 cm horizontal motions were obtained in the southwest, northwest, and west directions. The quantity of horizontal motions, however, was smaller in the south of the fault stations UCOE (approximately 9-10 cm) and PENA from the COMET-LiCSAR analysis showed that the GNSS and InSAR solution mirrors the pattern of earthquakes. The GNSS and InSAR data were aligned by standardizing to a common spatial and temporal grid, with corrections for atmospheric delays and noise. The mirroring of patterns was evaluated by using correlaconsidered to validate the alignment and highlight any discrepancies.