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[1]李 姣,姜金钟,王光明,等.2018年云南通海2次MS5.0地震震源机制解及深度测定[J].地震研究,2021,(02):133-144.
 LI Jiao,JIANG Jinzhong,WANG Guangming,et al.Focal Mechanism and Focal Depth Determination of the Two Tonghai,Yunnan,MS5.0 Earthquakes in 2018[J].Journal of Seismological Research,2021,(02):133-144.
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2018年云南通海2次MS5.0地震震源机制解及深度测定(PDF/HTML)

《地震研究》[ISSN:1000-0666/CN:53-1062/P]

卷:
期数:
2021年02期
页码:
133-144
栏目:
出版日期:
2021-06-30

文章信息/Info

Title:
Focal Mechanism and Focal Depth Determination of the Two Tonghai,Yunnan,MS5.0 Earthquakes in 2018
作者:
李 姣姜金钟王光明付 虹
(云南省地震局,云南 昆明 650224)
Author(s):
LI JiaoJIANG JinzhongWANG GuangmingFU Hong
(Yunnan Earthquake Agency,Kunming 650224,Yunnan,China)
关键词:
通海地震 CAP方法 sPn深度震相 震源机制解 震源深度
Keywords:
Tonghai earthquake CAP method sPn depth-phase focal mechanism focal depth
分类号:
P315.33
DOI:
-
摘要:
准确的震源机制解和震源深度是深入理解地震发震机理的基础。针对2018年8月13、14日在云南通海发生的2次MS5.0地震,利用云南地震台网30多个宽频带地震仪的波形记录,采用3个不同的区域速度模型和CAP方法获得了2次地震的震源机制解及矩心深度,并选取方位角约为300°的不同震中距的多个台站记录到的sPn深度震相准确测定了2次地震的初始破裂深度。结果表明:①基于数量更多、方位角覆盖较好的近台宽频带地震波形,在不同频率域内利用3个速度模型反演得到了2次地震的矩心深度分别为8 km和7 km; ②利用震中距大于260 km、方位角约300°的多个地震台记录波形的sPn和Pn震相的到时差,测定2次地震的初始破裂深度约为10 km,2种深度的差异可能是反映了主震沿断层面自下向上扩展的破裂过程; ③结合双差重定位及CAP反演结果,初步认为2次MS5.0地震的震源机制解应该是一致的,2018年2次通海MS5.0地震的发震断层应该为同一条左旋走滑型断层,其断层面走向/倾角/滑动角约为20°/75°/-10°。
Abstract:
Accurate earthquake parameters(e.g.focal mechanism and depth)are crucial for understanding the seismogenic mechanism.Based on waveforms of the 2018 Tonghai,Yunnan,MS5.0 earthquakes recorded by more than 30 broadband seismic stations of the Yunnan Earthquake Networks,we invert their focal mechanisms and depths by using Cut-and-Paste(CAP)method and three different regional velocity models.We also employ sPn depth-phases recorded by different stations situated at the azimuth of ~300° to estimate the focal depth of the Tonghai MS5.0 double earthquakes.The results are as follows:① Based on more broadband waveforms of near-earthquakes with better azimuth coverage,the obtained centroid depths(8 km and 7 km)of the two earthquakes inverted from different velocity models and frequency bands are more reliable.② By using sPn depth-phases at different stations with similar azimuth(~300°),we determine that the initial rupture depth of the two earthquakes are both about 10 km,which may indicate the rupture directivity(from bottom to top)of the earthquakes.③ According to the Double-difference relocation and our CAP inversions,we preliminarily infer that the Tonghai double earthquakes should occur on the same fault plane,whose parameters,strike/dip/rake,could be 20°/75°/-10°.

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备注/Memo

备注/Memo:
收稿日期:2021-01-04
基金项目:云南省地震局科技专项基金(2018ZX01)、云南省地震局“地震机理与孕震环境研究”创新团队及云南省科技计划项目基础研究青年项目(2018FD158)联合资助.
更新日期/Last Update: 2021-06-30