An Innovative Approach for Estimating Coseismic Surface Uplifts Using Ionospheric Observations From Remote GNSS Stations: First Application for the 2025 Myanmar Earthquake

Abstract

The Mw 7.7 Myanmar earthquake on 28 March 2025 ruptured ∼480 km of the Sagaing Fault. Its fault slip distribution remains poorly constrained by three‐dimensional surface displacement data due to sparse GNSS‐coverage near the fault. Satellite‐based synthetic aperture radars capture meters of right‐lateral displacements but isolating vertical crustal movements from these measurements is challenging. We present a new way to map vertical displacements distributed along the fault using ionospheric total electron contents (TEC) variability measured by GNSS stations located >300 km away from the epicenter along the India‐Myanmar border. We identified three distinct peaks in the TEC time‐series. The arrival times and amplitudes of these peaks are used to determine the positions and relative strengths of three acoustic wave sources. These results are compared with slip distribution inferred from seismological observations. The study demonstrates the capability of this innovative‐approach to constrain coseismic uplifts indirectly using ionospheric data at remote GNSS stations.