Strike-slip restraining screwed fault geometry reconstructed from the 2025 Myanmar earthquake

Daisuke Sato , Okuwaki Ryo, Yuji Yagi, Yukitoshi Fukahata

We present a fault surface model of the 2025 Mw 7.7 Myanmar earthquake based on the potency density tensor inversion (PDTI) of teleseismic P-waves combined with surface reconstruction from distributed potency tensor solutions. Our source model demonstrates that the earthquake fault is twisted, varying the dip angle along strike. Inferred fault twists are prominent near fault-segment junctions, around which respective rupture episodes are shown reflected and arrested. Those obtained underground fault images are warranted by the polarity of teleseismic P-waves sensitive to dip-angle variations. Since the reconstructed fault twists, which fit interseismic geodetic surveys, have the potential to restrain rupture propagations, geometrical irregularities detected around segment junctions provide a consistent explanation of why this earthquake nearly halted several times.