Upper-plate splay fault earthquakes along the Arakan subduction belt recorded by uplifted coral microatolls on northern Ramree Island, western Myanmar (Burma)

摘要

Highlights?We identified earthquakes produced by a splay fault offshore western Myanmar.?One event is likely to have occurred in 1848, with magnitude between 6.8 and 7.2.?These splay fault events may pose higher hazards for local coastal communities.?The importance of splay fault ruptures may be underestimated in subduction zones.AbstractUpper-plate structures that splay out from the megathrusts are common features along major convergent plate boundaries. However, their earthquake and tsunami hazard potentials have not yet received significant attention. In this study, we identified at least one earthquake event that may have been produced by an upper-plate splay fault offshore western Myanmar, based on U–Th ages of uplifted coral microatolls. This event is likely an earthquake that was documented historically in C.E. 1848, with an estimated magnitude between 6.8 and 7.2 based on regional structural characteristics. Such magn