Seismological and Gravity Data Integration to Derive Regional Fault and Subduction Systems in Myanmar

¹ Department of Geophysical Engineering, Universitas Syiah Kuala, Aceh, Indonesia
² Department of Physics, Universitas Syiah Kuala, Aceh, Indonesia
³ Tsunami and Disaster Mitigation Research Center, Universitas Syiah Kuala, Banda Aceh, Indonesia
⁴ Department of Earth and Planetary Science, Institute of Science Tokyo

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Tectonic activity in Myanmar is influenced by the convergence of the Indian Plate and the Burma Plate, which form an active subduction zone in western Myanmar (Rakhine) and the Sagaing Fault system in eastern Myanmar. These two tectonic zones generate significant earthquakes with shallow to intermediate depths. This study aims to interpret the tectonic characteristics of the region through an integrated approach that combines seismicity analysis, gravity anomaly modeling based on tilt derivative and waveform inversion using a Bayesian Bootstrap approach. Earthquake data were obtained from the USGS catalog for 2010–2025, while waveform data were downloaded from the IRIS database, focusing on events with Mw > 5.5. Gravity data used in this study were sourced from the TOPEX satellite. Preliminary analysis of seismicity distribution and hypocenter depths indicates a clear plate convergence pattern and active fault systems orientation across the study area. These results were then compared with satellite gravity anomaly data, which reflected variations in crustal density. The correlation between seismicity and gravity anomalies was used to interpret the geometry of the regional geological structures. Earthquake source parameters were analyzed through waveform inversion to obtain more detailed information, such as fault plane orientation, source mechanism, and refined hypocenter location. Several earthquake events were selected for inversion based on data completeness and signal quality. The waveform inversion results show misfit values below 0.6, indicating high-quality solutions. The inversion results reveal that right-lateral strike-slip mechanisms dominate earthquakes along the Sagaing Fault, while those in the Rakhine Subduction Zone are predominantly thrust faulting events.