近日，美国麻省理工学院Jared Bryan团队揭示了地壳应力和破坏在里奇克雷斯特断裂带的整个地震周期中不断演化。相关论文于2025年9月18日发表在《科学》杂志上。

地震突然释放了构造应力，这种应力随着时间的推移，通过断层和周围火山的耦合演化而缓慢形成。地震波速度可以跟踪地壳变形和应力变化，但典型的监测方法对浅层最敏感。

利用接收函数，研究组跟踪了2019年里奇克雷斯特地震序列中整个顶部的破裂带波速和各向异性变化。浅层同震波速下降在几个月内恢复，而更深的地震后波速下降持续数年，没有可测量的恢复。持续的深度波速下降可能反映了震后变形导致的累积损伤，这表明两种可能的情况：(i)缓慢的震间恢复，波速和各向异性跟踪长期应力演化；或（ii）未成熟断裂带的永久变形。这两种情况都影响地震旋回的动力学和能量收支。

附：英文原文

Title: Crustal stresses and damage evolve throughout the seismic cycle of the Ridgecrest fault zone

Author: Jared Bryan, William B. Frank, Pascal Audet

Issue&Volume: 2025-09-18

Abstract: Earthquakes abruptly release tectonic stress that builds slowly over time through the coupled evolution of faults and the surrounding crust. Seismic wavespeeds track crustal deformation and stress changes, but typical monitoring methods are most sensitive to shallow depths. Using receiver functions, we tracked rupture-zone wavespeed and anisotropy changes throughout the crust during the 2019 Ridgecrest earthquake sequence. Shallow coseismic wavespeed reductions recovered within months, whereas a deeper postseismic wavespeed drop persisted without measurable recovery over several years. The deep, persistent wavespeed drop likely reflects accumulating damage driven by postseismic deformation, suggesting two possible scenarios: (i) a slow interseismic recovery where wavespeed and anisotropy track long-term stress evolution; or (ii) permanent deformation of an immature fault zone. Both scenarios affect the dynamics and energy budget of the seismic cycle.

DOI: adu9116

Source: https://www.science.org/doi/10.1126/science.adu9116