Xu Liuwei, Ji Chen, Meng Lingsen, Ampuero Jean-Paul, Yunjun Zhang, Mohanna Saeed, Aoki Yosuke
Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, Los Angeles, CA, USA.
Department of Earth Science, University of California, Santa Barbara, Santa Barbara, CA, USA.
Science. 2024 Aug 23;385(6711):871-876. doi: 10.1126/science.adp0493. Epub 2024 Aug 22.
To reveal the connections between the 2024 moment magnitude () 7.5 Noto earthquake in Japan and the seismicity swarms that preceded it, we investigated its rupture process through near-source waveform analysis and source imaging techniques, combining seismic and geodetic datasets. We found notable complexity in the initial rupture stages. A strong fault asperity, which remained unbroken in preceding seismic swarms, slowed down the rupture. Then, a second rupture initiated at the opposite edge of the asperity, and the asperity succumbed to double-pincer rupture fronts. The failure of this high-stress drop asperity drove the earthquake into a large-scale event. Our observations help unravel the crucial role of fault asperities in controlling swarm migration and rupture propagation and underscore the need for detailed seismological and interdisciplinary studies to assess seismic risk in swarm-prone regions.
为揭示2024年日本能登矩震级（Mw）7.5级地震与其前震群之间的联系，我们结合地震和大地测量数据集，通过近源波形分析和震源成像技术研究了其破裂过程。我们发现初始破裂阶段存在显著的复杂性。一个在前震群中未破裂的强断层凹凸体减缓了破裂速度。然后，第二次破裂在凹凸体的相对边缘开始，凹凸体屈服于双钳形破裂前沿。这个高应力降凹凸体的破坏将地震推向了大规模事件。我们的观测结果有助于揭示断层凹凸体在控制震群迁移和破裂传播中的关键作用，并强调需要进行详细的地震学和跨学科研究，以评估易发生震群地区的地震风险。
