| Abstract Submission No. | ABS-3.1-0125 |
| Title of Abstract | Seismic Structure of Myanmar: Implications for Crustal Structure and Tsunami Hazards |
| Authors | Dr. Mamuni Sucheeta Ekka*, Dr. Ch. Patanjali Kumar, Dr. Sudheer Joseph |
| Organisation | Indian National Centre for Ocean Information Services (INCOIS) |
| Address | Indian National Centre For Ocean Information Services HYDERABAD, Telangana, India Pincode: 500090 E-mail: mse.incois@gmail.com |
| Country | India |
| Presentation | Oral |
| Abstract | On 28 March 2025, a Mw 7.7 earthquake, followed by a Mw 6.7 aftershock, struck the tectonically complex Indo-Burma subduction zone at a shallow depth of 10 km. Surface wave tomography (SWT) based on Rayleigh wave dispersion (RWD) was applied to earthquake events (≥ M5.5) recorded by 46 IRIS broadband stations (2000-2025) to image the crustal structure of the Myanmar region. Shear-wave velocity (Vs) models reveal a low-velocity zone at 40-45 km depth, indicating significant heterogeneity. In eastern and central Myanmar, Moho depths (~20-30 km) suggest thinner crust and reduced subduction influence, whereas in western Myanmar (Indo-Burma Ranges), a deeper Moho (~30 km) near the Indian-Burma plate interface points to strong seismic coupling. Such locked segments are capable of generating large megathrust earthquakes, as reflected in the recent sequence that significantly impacted the Sagaing and Mandalay regions. Hydrated LVZs in these zones appear to control earthquake size, location, and depth along the Indo-Burma Arc, which also governs tsunami generation. Overall, the tomography results provide critical structural insights for identifying high-risk rupture zones, thereby contributing to improved seismic and tsunami hazard assessment in the region. |
| Keywords | Rayleigh wave tomography, Myanmar, Seismogenic zones, Tsunami hazard, Shear-wave velocity. |