近日，美国内华达大学J. D. Kirkpatrick团队揭示了极端板块边界局部化促进了日本海沟浅层地震滑动。该项研究成果发表在2025年12月18日出版的《科学》杂志上。
2011年东日本9.1级大地震在特大地震中极为特殊，其最大滑移量（约50-70米）出现在板块边界巨型逆冲断层的最浅部。国际大洋发现计划第405航次获取的钻孔岩芯与地球物理测井数据表明，该巨型逆冲断层优先发育于俯冲太平洋板块沉积层内远洋粘土的顶部或底部——这些位置普遍存在显著的物理性质差异。这一特征在前缘棱柱体泥岩与俯冲沉积体的主要力学接触面上形成了一条狭窄的弱断层带，从而加剧了浅层地震滑移的倾向。研究组揭示，相较于缺乏软弱粘土层的俯冲带，日本海沟区域可能更易于发生具有大尺度浅层滑移的破裂事件。
附：英文原文
Title: Extreme plate boundary localization promotes shallow earthquake slip at the Japan Trench
Author: J. D. Kirkpatrick, H. M. Savage, C. Regalla, S. Shreedharan, C. Ross, H. Okuda, U. Nicholson, K. Ujiie, R. Hackney, M. Conin, P. Pei, S. Satolli, J. Zhang, P. Fulton, M. Ikari, S. Kodaira, L. Maeda, N. Okutsu, S. Toczko, N. Eguchi, Expedition Scientists, P. Bellanova, C. Brown, M. Brunet, M. R. Castillo, Y.-C. Chang, M.-L. Doan, J. Everard, A. Fintel, J. Ford, R. Fukuchi, A. Gough, H. Guo, D. Gürer, M. Hagino, Y. Hamada, H. Hosono, M.J. Jurado, A. Ijiri, T. Ishikawa, M. Iwai, T. Jeppson, N. Kamiya, T. Kanamatsu, A. LaPlante, W. Lin, A. Miyakawa, Y. Morono, Y. Nakamura, C. Pizer, T. Rasbury, R. Robertson, K. Schaible, H. Sone, C. Sun, T. Uchida, P. Vannucchi, A. Yamaguchi, Y. Yamamoto, T. Yoshimoto
Issue&Volume: 2025-12-18
Abstract: The 2011 Mw9.1 Tohoku-oki earthquake is exceptional among great earthquakes for having peak slip of ~50-70 m on the shallowest portion of the plate boundary megathrust. Drill cores and geophysical logs from International Ocean Discovery Program Expedition 405 demonstrate that the megathrust preferentially develops at the top or base of the pelagic clay in the sedimentary layers present on the incoming Pacific Plate, where pronounced contrasts in physical properties occur. This results in a narrow, weak fault located at a major mechanical contact between frontal prism mud and subducted sediments, which enhances the tendency for shallow seismic slip, suggesting the Japan Trench may be more susceptible to ruptures with large shallow slip than margins without weak clays.
DOI: ady0234
Source: https://www.science.org/doi/10.1126/science.ady0234