2025年Mw7.1 丁日（チベット南部）地震における応力摂動の解読

The 2025 moment magnitude (M_w) 7.1 Dingri earthquake in Southern Xizang, China, caused severe devastation and exhibited a complex stress evolution. Its northward unilateral rupture along the twisted, west-dipping graben edge generated ~2 MPa of dynamic stress, triggering blind coseismic slip on an east-dipping fault. Coseismic stress perturbations activated over 50 previously unmapped fault segments, mostly with aseismic slip, while also inducing an early viscoelastic response in the weak middle-to-lower crustal layer below ~20 km depth. Here we explain these behaviours by deciphering the stress perturbations through earthquake cycle observations and models. A major implication is that tracking stress evolution throughout an earthquake provides critical insights into earthquake mechanics.