|本期目录/Table of Contents|

[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,2021,44(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,2021,44(02):133-144.
点击复制

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:
44
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 Jiao; JIANG Jinzhong; WANG Guangming; FU 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°.

参考文献/References:

安晓文,常祖峰,陈宇军,等.2018.云南第四纪活动断裂暨《云南第四纪活动断裂分布图》[M].北京:地震出版社.
崇加军,倪四道,曾祥方.2010.sPL,一个近距离确定震源深度的震相[J].地球物理学报,53(11):2620-2630.
邓起东,张培震,冉勇康,等.2003.中国活动构造与地震活动[J].地学前缘,10(S1):66-73.
高立新,刘芳,赵蒙生,等.2007.用sPn震相计算震源深度的初步分析与应用[J].西北地震学报,29(3):213-218.
胡萌萌,吴中海,黄小龙,等.2020.云南1588年通海—曲江7.0级地震的发震断层厘定及小江断裂带南端的未来强震危险性问题[J].地质学报,94(10):3090-3105.
皇甫岗.2009.云南地震活动性研究[D].合肥:中国科学技术大学.
李姣,姜金钟,杨晶琼.2020.2017年漾濞MS4.8和MS5.1地震序列的微震检测及重定位[J].地震学报,42(5):527-542.
罗艳,曾祥方,倪四道.2013.震源深度测定方法研究进展[J].地球物理学进展,28(5):2309-2321.
潘睿,姜金钟,付虹,等.2019.2017年云南漾濞MS5.1及MS4.8地震震源机制解和震源深度测定[J].地震研究,42(3):338-348.
任克新,邹立晔,刘瑞丰,等.2004.用sPn计算内蒙地震的震源深度[J].地震地磁观测与研究,25(3):24-31.
孙茁,吴建平,房立华,等.2014.利用sPn震相测定芦山MS7.0级地震余震的震源深度[J].地球物理学报,57(2):430-440.
王光明,刘自凤,赵小艳,等.2018.2018年云南通海MS5.0地震序列重定位及发震构造讨论[J].地震研究,41(4):503-510.
王洋,张波,侯建军,等.2015.曲江断裂晚第四纪活动特征及滑动速率分析[J].地震地质,37(4):1177-1192.
王月,孟令媛,韩颜颜,等.2020.2018年云南通海MS5.0震群序列重定位及震源区速度结构成像[J].地震研究,43(2):331-339.
韦生吉,倪四道,崇加军,等.2009.2003年8月16日赤峰地震:一个可能发生在下地壳的的地震?[J].地球物理学报,52(1):111-119.
闻学泽,杜芳,龙峰,等.2011.小江和曲江—石屏两断裂系统的构造动力学和强震序列的关联性[J].中国科学:地球科学,41(5):713-724.
吴建平,明跃红,王椿镛.2004.云南地区中小地震震源机制及构造应力场研究[J].地震学报,26(5):457-465.
姚华建.2020.中国川滇地区公共速度模型构建:思路与进展[J].中国科学:地球科学,50(9):1319-1322.
易桂喜,龙锋,张致伟.2012.汶川MS8.0地震余震震源机制时空分布特征[J].地球物理学报,55(4):1213-1227.
张瑞青,吴庆举,李永华,等.2008.汶川中强余震震源深度的确定及其意义[J].中国科学:地球科学,38(10):1234-1241.
张之立,刘新美.1982.1970年1月5日云南通海地震的震源特征[J].地球物理学报,25(5):441-447.
郑勇,马宏生,吕坚,等.2009.汶川地震强余震(MS≥ 5.6)的震源机制解及其与发震构造[J].中国科学:地球科学,39(4):413-426.
郑勇,谢祖军.2017.地震震源深度定位研究的现状与展望[J].地震研究,40(2):167-175.
Jiang J Z,Li J,Fu H.2019.Seismicity analysis of the 2016 MS5.0 Yunlong Earthquake,Yunnan,China and its tectonic implications[J].Pure and Applied Geophysics,176(3):1225-1241.
Ma S,Atkinson G M.2006.Focal depths for small to moderate earthquakes(mN ≥ 2.8)in Western Quebec,Southern Ontario,and Northern New York[J].Bulletin of the Seismological Society of America,96(2):609-623.
Mori J.1991.Estimates of velocity structure and source depth using multiple P waves from aftershocks of the 1987 Elmore Ranch and Superstition Hills,California,earthquakes[J].Bulletin of the Seismological Society of America,81(2):508-523.
Qian Y Y,Chen X F,Luo H,et al.2019.An extremely shallow MW4.1 thrust earthquake in the eastern Sichuan Basin(China)likely triggered by unloading during infrastructure construction[J].Geophysical Research Letters,46(23):13775-13784.
Snoke J A.2009.Traveltime Tables for iasp91 and ak135[J].Seismological Research Letters,80(2):260-262.
Stein S,Wiens D A.1986.Depth determination for shallow teleseismic earthquakes:Methods and results[J].Reviews of geophysics,24(4),806-832.
Tan Y,Helmberger D V.2007.A new method for determining small earthquakes source parameters using short-period P waves[J].Bulletin of the Seismological Society of America,97(4):1176-1195.
Waldhauser F,Ellsworth W L.2000.A double difference earthquake location algorithm method and application to the Northern Hayward Fault,California[J].Bulletin of the Seismological Society of America,96(6),1353-1368.
Wells D L,Coppersmith K J.1994.New empirical relationship among magnitude,rupture length,rupture width,rupture area,and surface displacement[J].Bulletin of the Seismological Society of America,84(4):974-1002.
Weng H,Yang H.2017.Seismogenic width controls aspect ratios of earthquake ruptures[J].Geophysical Research Letters,44(6):2725-2732.
Yang H F,Zhou P C,Fang N,et al.2020.A shallow shock:the 25 February 2019 ML4.9 earthquake in the Weiyuan shale gas field in Sichuan,China[J].Seismological Research Letters,91(6):3182-3194.
Zhao L S,Helmberger D V.1994.Source estimation from broadband regional seismograms[J].Bulletin of the Seismological Society of America,84(1):91-104.
Zhu L P,Helmberger D V.1996.Advancement in source estimation techniques using broadband regional seismograms[J].Bulletin of the Seismological Society of America,86(5):1634-1641.
Zhu L P,Rivera L A.2002.A note on the dynamic and static displacements from a point source in multilayered media[J].Geophysical Journal International,148(3):619-627.

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