Insights Into Seismic‐Induced Ionospheric Perturbation Following the 2025 Myanmar Earthquake

A major earthquake with a magnitude of M W = 7.7, followed by several aftershocks, occurred in Mandalay, Myanmar, on 28 March 2025. This study aims to report on the co‐seismic ionospheric disturbances caused by the event, based on a multi‐instrument approach that was adopted to examine co‐seismic effects. Frequency analysis and filtering techniques were employed to distinguish between different acoustic or gravity wave signatures in the ionosphere. Ground seismic stations provided wave velocity estimation, while the velocity of co‐seismic ionospheric wavefronts was estimated using Total Electron Content fluctuations from GNSS receivers. Using the collocation of a seismic station with an Ionosonde station, it has been possible to estimate the vertical propagation time of acoustic waves, resulting in multi‐cusp signature formation. Additionally, radio occultation electron density profiles from the COSMIC‐2 mission have been analyzed in search of topside signatures. While horizontal velocities of co‐seismic ionospheric wavefronts were estimated between 0.8 and 3.6 km/s, their non‐isotropic distribution with epicentral distance revealed information about the background generation mechanism. For each seismic event, studies related to the co‐seismic ionospheric behavior could provide insightful information relating the coupling between ground and upper atmosphere. This study exploits a combination of data sets for a comprehensive understanding of the ionospheric disturbances associated with an earthquake.