[1]WANG Guangming,PENG Guanling,ZHAO Xiaoyan,et al.Seismic Risk of the Weixi-Qiaohou Fault Zone Based on Temporal-spatial Distribution Characteristics of Earthquake Sequences[J].Journal of Seismological Research,2021,44(03):367-379.
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Journal of Seismological Research[ISSN 1000-0666/CN 53-1062/P] Volume:
44
Number of periods:
2021 03
Page number:
367-379
Column:
Public date:
2021-10-20
- Title:
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Seismic Risk of the Weixi-Qiaohou Fault Zone Based on Temporal-spatial Distribution Characteristics of Earthquake Sequences
- Author(s):
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WANG Guangming; PENG Guanling; ZHAO Xiaoyan; FU Hong
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(Yunnan Earthquake Agency,Kunming 650224,Yunnan,China)
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- Keywords:
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the Weixi-Qiaohou fault zone; the Yangbi MS6.4 earthquake; earthquake relocation; attenuation of the aftershock sequence; earthquake hazard
- CLC:
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P315.2
- DOI:
-
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- Abstract:
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Before the Yangbi MS6.4 earthquake on May 21,2021,three groups of MS≥5.0 earthquakes have occurred continuously,indicating that the seismic activity of the Weixi-Qiaohou fault zone has increased significantly since 2013.In this paper,we employ double-difference relocation algorithm to relocate earthquake sequences around the Weixi-Qiaohou fault zone since 2013,and use ZMAP to calculate the b-value and p-value of these sequences.The earthquake sequences around the Weixi-Qiaohou fault zone present obviously two different types of temporal-spatial distribution characteristics.Three earthquake sequences concentrate in a NW-trend band,which is parallel with the Weixi-Qiaohou fault,and the length-width ratios of the epicenter distribution of these earthquake sequences are larger.Furthermore,these three earthquake sequences decay faster and their b-values are relatively lower,while the Yunlong MS5.0 earthquake sequence in 2016 concentrates to a NE-trend band,and the length-width ratio of the epicenter distribution is relatively smaller.Also,the Yunlong MS5.0 earthquake sequence decays slower than the other three earthquake sequences,and its b-value is relatively higher.A contrastive analysis of earthquake sequences around the Weixi-Qiaohou fault zone shows that the possibility of large destructive aftershocks following the 2021 Yangbi MS6.4 earthquake sequence is small.Based on a comprehensive analysis of the spatial-temporal distribution characteristics of the moderately-strong earthquakes in the Weixi Qiaohou fault zone since 2013 and regional geological structure study,it is considered that MS≥5.0 earthquakes in this area may migrate to the Southeast(or the North)in the future.