| Abstract Submission No. | ABS-3.1-0201 |
| Title of Abstract | Three dimensional co-seismic deformation and fault slip model due to the 28 March 2025, Mw 7.7 Mandalay (Myanmar) earthquake from SAR and optical images |
| Authors | Sreejith KM*, Aswini S |
| Organisation | Space Applications Centre, Indian Space Research Organization, Ah |
| Address | 4136, Geosciences Division, PGSG, EPSA Ahmedabad, Gujarat, India Pincode: 380015 E-mail: sreejith81@gmail.com |
| Country | India |
| Presentation | Oral |
| Abstract | The destructive 28 March 2025, Mandalay earthquake (M w =7.7) is one of the largest earthquakes (hereafter referred as Myanmar earthquake) to have struck Myanmar and neighbouring countries. Sentinel-1 Synthetic Aperture Radar (SAR) images were utilised to estimate azimuth and range displacements using pixel-offset tracking (POT) technique. 3-D co-seismic deformation field due to the 2025 Myanmar earthquake were constrained from ground displacements measured from ascending and descending geometries. Horizontal component of the co-seismic displacements were independently estimated using sub-pixel correlation of optical images from Sentinel-2 satellite. The results suggests that the 2025 Myanmar earthquake ruptured a ~480 km section of the Sagaing fault with a maximum displacement of 4 m in horizontal and 1 m in vertical directions. While the SAR measurements could constrain the 3-D co-seismic deformation field, high-resolution horizontal displacements from optical images could capture the surface rupture along the Sagaing fault. We use the 3-D deformation field and fault trace information to model the co-seismic rupture on the causative fault. We infer average slip 3-5 m on a steeply dipping fault extending for a distance ~430 km toward south and 50 km towards north from the hypocentre. The model suggests maximum slip distribution upto a depth of 12 km. Present results and paleoseismological inferences suggest repeated large earthquakes with significant rupture overlap along Sagaing fault, implying potential future seismic hazard. |
| Keywords | 28 March 2025, Mw 7.7 Mandalay (Myanmar) earthquake; co-seismic deformation, Synthetic Aperture Radar, fault slip model |