An MS 6.4 earthquake occurred near Yangbi County, Dali Bai Autonomous Prefecture, Yunnan Province, at 21:48 on May 21, 2021. The earthquake location is characterized by complex geological structures, with multiple active faults distributed around the epicenter that is located at the west edge of the Sichuan-Yunnan rhombic block (25.67°N, 99.87°E). A total of 42 ground cracks are found by earthquake field investigations. The cracks are mainly concentrated in the Ⅷ degree area on the west side of the Yangbi River. Among these, 9 coseismic tectonic ground cracks generated by shear fractures are found in three villages (i.e., Akechang, Meijia-Lijia, and Huajiazhuang), which are distributed along the strike of the northwest-trending linear folds, showing the tectonic characteristics of right-lateral tension or left-stepping cracks. The structural attribute of ground cracks sustains the kinematic properties of the Weixi-Qiaohou fault, namely right-lateral strike-slip.

Changwei Liu;Zufeng Chang;Jianlin Li

Yunnan Earthquake Disaster Prevention Center,Yunnan Earthquake Agency,Kunming,China

地震研究进展（英文）

[1]Changwei Liu;Zufeng Chang;Jianlin Li-.Characteristics of ground cracks caused by the MS 6.4 Yangbi earthquake and the corresponding tectonic significance)[J].地震研究进展（英文）,2022(02):21-29

Akechang,Meijia,Lijia,Huajiazhuang,Weixi,Qiaohou

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