A multiple asymmetric bilateral rupture sequence derived from the peculiar tele-seismic P-waves of the 2025 Mandalay, Myanmar earthquake

Abstract

A large strike-slip earthquake occurred in central Myanmar on March 28, 2025. The aftershock distribution suggests that the rupture of the mainshock propagated mainly to the south. However, a large-amplitude phase lasting 20 s, followed by a short-period pulse-like phase, were observed at the stations on the north side of the source, while on the south side, tremor-like phases with multiple peaks continued for 90 s. Using the potency density tensor inversion method, we explain the "unusual" waveform signature of the Myanmar earthquake by a multiple, asymmetric bilateral rupture, involving boomerang-like back-rupture propagation and supershear.