To reveal the connections between the 2024 moment magnitude ( M w ) 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.

中文翻译：

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2024 年诺托地震中围绕群边缘断层粗糙体的双起始破裂


为了揭示 2024 年日本能登矩震级 (Mw) 7.5 级地震与之前的地震群之间的联系，我们通过近源波形分析和源成像技术，结合地震和大地测量数据集，研究了其破裂过程。我们发现初始破裂阶段非常复杂。强烈的断层粗糙度在之前的地震群中保持完整，减缓了破裂。然后，第二次破裂在粗糙体的相对边缘开始，并且粗糙体屈服于双钳破裂前沿。这种高应力降粗糙体的破坏导致地震成为大规模事件。我们的观察有助于揭示断​​层粗糙体在控制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来评估群多发地区的地震风险。