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地震 ›› 2024, Vol. 44 ›› Issue (1): 195-203.doi: 10.12196/j.issn.1000-3274.2024.01.017

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利用远场记录反演2023年甘肃积石山M6.2地震破裂过程

王安简, 高原   

  1. 中国地震局地震预测研究所, 地震预测重点实验室, 北京 100036
  • 收稿日期:2023-12-24 修回日期:2024-01-03 出版日期:2024-01-31 发布日期:2024-03-21
  • 通讯作者: 高原, 研究员。 E-mail: qzgyseis@163.com
  • 作者简介:王安简(1993-), 女, 安徽怀宁人, 博士后, 主要从事地震学研究。
  • 基金资助:
    国家自然科学基金项目(60244402)

Inversion of the Rupture Process of the 2023 Jishishan M6.2 Earthquake in Gansu by Teleseismic Data

WANG An-jian, GAO Yuan   

  1. Key Laboratory of Earthquake Prediction, Institute of Earthquake Forecasting, China Earthquake Administration, Beijing 100036, China
  • Received:2023-12-24 Revised:2024-01-03 Online:2024-01-31 Published:2024-03-21

摘要: 2023年12月18日23时59分在甘肃临夏积石山发生了M6.2地震, 地震发震断层推测为此前尚未充分认知的积石山东缘断裂。 本文利用远场地震记录反演分析了2023年积石山M6.2地震的破裂过程。 结果表明, 地震破裂持续时间约8 s, 主要破裂长度为20~25 km, 宽度约25 km。 在走向为164°的节面Ⅰ上, 整个破裂过程释放的标量地震矩为1.46×1018 N·m, 相当于矩震级MW6.05, 最大同震滑动量约为0.25 m, 估计矩心深度为9.5 km, 破裂主要沿断层走向SSE向扩展; 在走向为303°的节面Ⅱ上, 释放的标量地震矩为1.38×1018 N·m, 相当于矩震级MW6.03, 最大同震滑动量约为0.19 m, 矩心深度为11.1 km。 破裂呈现双侧形态, 主要沿SE方向, 并存在NW向的拓展趋势。

关键词: 2023年积石山M6.2地震, 震源破裂过程, 波形反演, 同震滑动

Abstract: This study utilized teleseismic data to invert and analyze the rupture process of the 2023 Jishishan M6.2 earthquake in Gansu, China. The causative fault of the earthquake was likely to be a previously unclear local fault, the Jishishan eastern margin fault. The results indicated that the earthquake rupture lasted approximately 8 s, with a primary rupture length of 20~25 km and a width of about 25 km. On the nodal plane Ⅰ with a strike of 164°, the entire rupture process released a scalar seismic moment of 1.46×1018 N·m, equivalent to a moment magnitude of MW6.05 with a maximum coseismic slip of 0.25 m. The estimated centroid depth was 9.5 km and the rupture primarily extended in the south-southeast direction along the fault strike. On the nodal plane Ⅱ with a strike of 303°, the scalar seismic moment released was 1.38×1018 N·m, equivalent to a moment magnitude of MW6.03, with a maximum coseismic slip of 0.19 m and a centroid depth of 11.1 km. The rupture exhibited a bilateral pattern, predominantly extending in the southeast direction, with a northwestward expansion trend.

Key words: The 2023 Jishishan M6.2 earthquake, Source rupture process, Waveform inversion, Coseismic slip

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