标题:Detailed geometry of the subducting Indian Plate beneath the Burma Plate and subcrustal seismicity in the Burma Plate derived from joint hypocenter relocation
摘要:With the aim of delineating the subducting Indian Plate beneath the Burma Plate, we have relocated earthquakes by employing teleseismic P -wave arrival times.We were able to obtain the detailed geometry of the subducting Indian Plate by constructing iso-depth contours for the subduction earthquakes at depths of 30–140 km.The strikes of the contours are oriented approximately N-S, and show an “S” shape in map view.The strike of the slab is N20°Eat25°N, but moving southward, the strike rotates counterclockwise to N20°Wat20°N, followed by a clockwise rotation to a strike of N10°E at 17.5°N, where slab earthquakes no longer occur.The plate boundary north of 20°N might exist near, or west, of the coast line of Myanmar.The mechanisms of subduction earthquakes are down-dip extension, and T axes are oriented parallel to the local dip of the slab.Subcrustal seismicity occurs at depths of 20–50 km in the Burma Plate.This activity starts near the 60-km-depth contour of the subduction earthquakes and becomes shallower toward the Sagaing Fault, indicating that this fault is located where the cut-off depth of the seismicity becomes shallower.