Present-day crustal deformation and slip rate along the southern Sagaing fault in Myanmar by GNSS observation

The Sagaing fault in Myanmar runs through the entire country and is responsible for major earthquakes, yet only its northern half has been studied geodetically to date. We analyzed Global Navigation Satellite System (GNSS) data to estimate crustal deformation along the central and southern parts of the Sagaing fault. We used a 2-dimensional dislocation model to estimate slip rate, locking depth and lateral offset between surface fault trace and downdip edge of the locked fault along the Sagaing (SGs), Meiktila (MTLs) and Bago (BGOs) segments of the fault. The estimated slip rate is 16-24 mm/yr with a locking depth of 10-16 km in our analysis for the central to southern segments, which is deeper than the locking depth of northern segment from previous studies. The slip rate is-23-24 mm/yr in the central part of the Sagaing fault, while it is probably slower (similar to 16 mm/yr) in the southern part of our study area. The predicted maximum shear strain from the optimal model is shifted from the surface fault trace. If the locked part of the fault connects directly from the deeper offset dislocation to the surface fault trace, it may be dipping with inferred values of 71 degrees E for the SGs and 78W for the MTLs, based on the distance between surface trace and the dislocation line at depth. The estimated potential magnitude of earthquakes for each segment as of 2021 are M-w similar to 7.3 in SGs, Mw similar to 7.4 in MTLs and Mw similar to 7.3 in BGOs, respectively.