[1]WANG Xia,SONG Meiqin,GUO Wenfeng,et al.Possible Coulomb Stress Interactions between the Three Main Earthquakes in the 1989 Datong-Yanggao Earthquake Swarm[J].Journal of Seismological Research,2022,45(04):560-569.[doi:10.20015/j.cnki.ISSN1000-0666.2022.0053]
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Journal of Seismological Research[ISSN 1000-0666/CN 53-1062/P] Volume:
45
Number of periods:
2022 04
Page number:
560-569
Column:
Public date:
2022-08-20
- Title:
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Possible Coulomb Stress Interactions between the Three Main Earthquakes in the 1989 Datong-Yanggao Earthquake Swarm
- Author(s):
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WANG Xia1; SONG Meiqin1; GUO Wenfeng1; CHEN Hui1; FANG Qiang2
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(1.Shanxi Earthquake Agency,Taiyuan 030021,Shanxi,China)(2.Guangshan Branch of the Xinyang Ecological Environment Bureau,Guangshan 465450,Henan,China)
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- Keywords:
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Coulomb stress; stress triggering; effective coefficient of friction; the Datong-Yanggao earthquake swarm
- CLC:
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P315.24
- DOI:
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10.20015/j.cnki.ISSN1000-0666.2022.0053
- Abstract:
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We calculated the co-seismic static Coulomb stress changes of the M5.7 earthquake,the M5.9 earthquake and the M5.6 earthquake in the 1989 Datong-Yanggao earthquake swarm,and analyzed the effects of different fault parameters on the Coulomb stress field,and quantitatively investigated the triggering relationships among these earthquakes by combining the distribution patterns of the aftershock sequences.The results show that the M5.7 shock may have been characterized by NW left-lateral strike-slip,followed by NE right-lateral strike-slip of the M5.9 shock,with conjugate activity of the seismogenic fault,and triggered the subsequent aftershocks.A comprehensive analysis of the distribution of events and the Coulomb stress changes suggests that the possible seismogenic mechanisms of the 1989 Datong-Yanggao earthquake swarm are:①In the context of the enhanced regional stress field,the 2 conjugate seismogenic faults were both close to the critical state of failure,and the NW-oriented Tuanbao fault ruptured firstly with lower yield stress; ②The NE-oriented Dawangcun fault was subsequently triggered rupture,and the NE-oriented rupture was predominant.The main aftershocks were distributed in NE direction,which was consistent with the direction of the NE principle compressive stress; ③The effective friction coefficients of the receiving faults in the study area were relatively high(over 0.4); ④The M5.9 earthquake triggered the aftershocks in the southwest region,and the aftershocks in the southeast region may be influenced by the M5.9 earthquake,and was controlled by the friction coefficient of the fault.Generally,there was a trigger relationship between the three M>5.5 earthquakes,and the M5.9 shock had a significant triggering effect on the surrounding faults.