An M6.4 earthquake struck Yangbi County,Dali Prefecture,Yun-nan Province,on May 21,2021,at 21:48 Beijing Time (2021-05-2113:48:37 UTC).Soon thereafter,at 2:04 UTC on May 22,2021(2021o05-2118:04:13 UTC),an M7.4 earthquake struck Madou County,Guoluo Prefecture,Qinghai Province.These two earth-quakes occurred in the southeastern edge and in high-altitude hin-terland of the eastern Tibetan Plateau respectively (Fig.1a),and both caused human casualties and property damage,triggering earthquake emergency response efforts.