1:45 PM - 2:00 PM
[O12-01] Interseismic crustal deformation and earthquake potential around the Sagaing fault, Myanmar, clarified by GNSS observation
★Invited Papers
Keywords:Crustal deformation, GNSS, Sagain Fault, Seismic potential
Myanmar is located in the plate boundary zone between the continental Eurasia (or Sunda) plate and the oceanic Indian plate. The oblique relative plate motion between two plates is significantly partitioned into a subducting motion along the Arakan trench and a lateral motion in Myanmar central basin. The Sagaing fault is a major right-lateral strike-slip fault extending over 1200 km, which accommodates the lateral motion and has generated M=>7 earthquakes in the past. The central part of the Sagaing fault is regarded as a seismic gap since a possible earthquake in 1839 (e.g., Hurukawa and Maung, 2011).
Tha Zin Htet Tin et al. (2022, J. Asian Earth Sci.) analyzed newly developed GNSS data with the existing data to clarify the interseismic deformation around the southern Sagaing fault. They estimated 16-24 mm/yr of the slip rate along the central and southern segments of the Sagaing fault using the 2-dimensional dislocation model. The central (Melkita) segment has the highest moment accumulation of 1.8 x 1018 N m/yr for a future earthquake. They also found that the maximum shear strain does not locate just on the fault trace, which implies the Sagaing fault may not be a pure vertical fault.
Tha Zin Htet Tin (2022, PhD Thesis, Kyoto Univ.) calculated 30-55% of the earthquake probability along the central segment of the Sagaing fault within the next 30 years using the Brownian Passage Time (BPT) Model. The Mw7.7 earthquake ruptured the seismic gap along the Sagaing fault on March 28, 2025.
In this presentation, we review the results of Tha Zin Htet Tin et al. (2022) and Tha Zin Htet Tin (2022) as well as the block model by Lindsey et al. (2023, EPSL) and discuss the relation between the interseismic deformation and the Mw7.7 earthquake. In addition, we introduce the results of a field survey on the surface rupture of the earthquake (Tha Zin Htet Tin, personal communication).
Tha Zin Htet Tin et al. (2022, J. Asian Earth Sci.) analyzed newly developed GNSS data with the existing data to clarify the interseismic deformation around the southern Sagaing fault. They estimated 16-24 mm/yr of the slip rate along the central and southern segments of the Sagaing fault using the 2-dimensional dislocation model. The central (Melkita) segment has the highest moment accumulation of 1.8 x 1018 N m/yr for a future earthquake. They also found that the maximum shear strain does not locate just on the fault trace, which implies the Sagaing fault may not be a pure vertical fault.
Tha Zin Htet Tin (2022, PhD Thesis, Kyoto Univ.) calculated 30-55% of the earthquake probability along the central segment of the Sagaing fault within the next 30 years using the Brownian Passage Time (BPT) Model. The Mw7.7 earthquake ruptured the seismic gap along the Sagaing fault on March 28, 2025.
In this presentation, we review the results of Tha Zin Htet Tin et al. (2022) and Tha Zin Htet Tin (2022) as well as the block model by Lindsey et al. (2023, EPSL) and discuss the relation between the interseismic deformation and the Mw7.7 earthquake. In addition, we introduce the results of a field survey on the surface rupture of the earthquake (Tha Zin Htet Tin, personal communication).