Details

Autor(en) / Beteiligte

• Tha Zin Htet Tin
• Nishimura, Takuya
• Hashimoto, Manabu
• Lindsey, Eric O.
• Aung, Lin Thu
• Min, Saw Myat
• Thant, Myo

Titel

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

Ist Teil von

• Journal of Asian earth sciences, 2022-05, Vol.228, p.105125, Article 105125

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

2022

Link zum Volltext

Quelle

ScienceDirect journals Piacenza

Beschreibungen/Notizen

• [Display omitted] •Crustal deformation along the central and southern Sagaing fault in Myanmar is studied using data from newly established GNSS (Global Navigation Satellite System) networks.•Locking depths are 10 km, 16 km, and 10 km for the Sagaing segment (SGs), Meiktila segment (MTLs), and Bago segment (BGOs) respectively from north to south.•The slip rates are 23 – 24 mm/yr for the Sagaing and Meiktila segments, while the southernmost Bago segment has a significantly slower slip rate of about 16 mm/yr than the others.•The Meiktila segment, which has not ruptured since the 19th century, is inferred to present the greatest seismic hazard, with both the deepest estimated locking depth and the highest slip rate among the three segments studied here.•The shift in center of peak strain rate between the two northern segments (Sagaing segment and Meiktila segment) might be related to the seismic gap in the central part of the Sagaing fault. 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 (~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°E for the SGs and 78°W 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 Mw ~7.3 in SGs, Mw ~7.4 in MTLs and Mw ~7.3 in BGOs, respectively.