美国德克萨斯大学地球物理研究所Charles A. Williams团队近日研究了钻孔观测捕捉到的南海海槽大型逆冲构造的迁移浅层慢滑。这一研究成果发表在2025年6月26日出版的《科学》杂志上。

近海俯冲带应变积累和释放模式与浅层同震滑动和海啸发生的可能性直接相关，但这些模式仍然难以捉摸。在这项工作中，研究组分析了日本本州岛南海俯冲带三个海上钻孔观测站的地层孔隙压力记录，以捕获沿板块边界最外缘的两次慢滑事件（SSE）的详细滑动时间史。

滑坡起始于海沟向陆地约30千米处；以每天1至2千米的速度向海迁移，到达距离海沟几公里以内，并可能突破海沟；并且与震颤和/或极低频地震的发生和迁移相吻合。SSE震源区处于高孔隙流体压力和低应力带，为将这些因素与浅层慢地震联系起来提供了明确的观测证据。

附：英文原文

Title: Migrating shallow slow slip on the Nankai Trough megathrust captured by borehole observatories

Author: Joshua R. Edgington, Demian M. Saffer, Charles A. Williams

Issue&Volume: 2025-06-26

Abstract: Patterns of strain accumulation and release offshore in subduction zones are directly linked to the potential for shallow coseismic slip and tsunamigenesis, but these patterns remain elusive. In this work, we analyze formation pore pressure records from three offshore borehole observatories at the Nankai subduction zone, Honshu, Japan, to capture detailed slip-time histories of two slow slip events (SSEs) along the outermost reaches of the plate boundary. Slip initiates ~30 kilometers landward of the trench; migrates seaward at 1 to 2 kilometers per day to within a few kilometers of, and possibly breaching, the trench; and coincides with the onset and migration of tremor and/or very-low-frequency earthquakes. The SSE source region lies in a zone of high pore fluid pressure and low stress, which provides clear observational evidence linking these factors to shallow slow earthquakes.

DOI: ads9715

Source: https://www.science.org/doi/10.1126/science.ads9715