Citation

Wang W, He J, Wang X, Zhou Y, Hao J, Zhao L, Yao Z. Sci. Bull. (Beijing) 2022; 67(5): 466-469.

Copyright

(Copyright © 2022, Holtzbrinck Springer Nature Publishing Group)

DOI

10.1016/j.scib.2021.11.009

PMID

36546165

Abstract

An M6.4 earthquake struck Yangbi County, Dali Prefecture, Yunnan Province, on May 21, 2021, at 21:48 Beijing Time (2021-05-21 13:48:37 UTC). Soon thereafter, at 2:04 UTC on May 22, 2021 (2021-05-21 18:04:13 UTC), an M7.4 earthquake struck Madou County, Guoluo Prefecture, Qinghai Province. These two earthquakes occurred in the southeastern edge and in high-altitude hinterland of the eastern Tibetan Plateau respectively (Fig. 1a), and both caused human casualties and property damage, triggering earthquake emergency response efforts. The occurrence of strong earthquakes at different sites within 5 h of each other indicates continuous tectonic movements and violent seismic activity on the Tibetan Plateau under the collisional convergence between the Indian and Eurasian continental plates [3]. Observations of crustal motion expose clockwise rotational deformation in the eastern Tibetan Plateau along the axis of the eastern Himalayan syntaxis [2], [4]. Furthermore, studies combining tectonic and historical seismic data with numerical simulations reveal that the shear effect of the eastward flow of crustal material within the Tibetan Plateau leads to active sinistral strike-slip faulting in the northern part of the plateau and dextral strike-slip faulting in the south [1], [3], [5]. The source mechanisms of these two events (Fig. S1 online) suggest that both earthquakes occurred in response to the strain induced by the current crustal deformation, which is consistent with the above deformation pattern of the Tibetan Plateau.

Language: en

Keywords

*Earthquakes; Environmental Monitoring; Tibet