Insight Into Major Active Faults in Central Myanmar and the Related Geodynamic Sources

Myanmar, one of the most active tectonic regions in the world, endures the risk of destructive earthquakes. Based on seismic data recorded at the recently deployed dense array of the China‐Myanmar Geophysical Survey in the Myanmar Orogen (CMGSMO), we detect 854 and locate 599 shallow earthquakes with high precision and determine the focal mechanisms of 40 earthquakes. We identify two NW‐SE trending fault zones accommodating dextral strike‐slip earthquakes beneath the Central Basin, indicating potential seismic risk in the region. We also recognize a nearly N‐S trending seismic zone in the overlying Indo‐Burma Ranges (IBR) crust near the Kabaw Fault (KBF). The earthquakes within this seismic zone mostly show thrusting focal mechanisms. Our results suggest that strike‐slip deformation dominates to the east of the KBF, while shortening is mainly confined to the west of the KBF in Central Myanmar. Myanmar in Southeast Asia suffers from disasters resulting from destructive earthquakes. However, the present knowledge on their causative faults is limited due to the deployment of few seismic observation stations in Myanmar. We deployed a seismic observation network containing 71 stations for 1.5 years and tried to identify unknown causative faults and their characteristics by studying the small earthquakes there. Our results suggest that larger areas than previously expected in Myanmar may encounter significant seismic hazards. More attention to mitigating hazards should be paid to the Central Basin and western mountain areas, where densely populated cities are located. We detect 854 shallow earthquakes and analyze the focal mechanisms of 40 events based on the data set from a new seismic array in MyanmarWe identify two fault zones in the Central Basin that may accommodate surplus strike‐slip deformations not taken up by the Sagaing FaultWe observe a lower‐crustal seismic zone west of the Kabaw Fault, which is controlled by eastward subduction of the Indian Plate