Abstract：We analyze and process the whole time observation data, from January 1, 2015 to May 20, 2021 of the water tube instrument and the extensometer within 200 km of the epicenter of the May 21, 2021 M6.4 Yangbi, Yunnan earthquake. We find that from 2019, the observation curves of the two sets of instruments at each station show trend change or the annual change amplitude decreases at the same time. There is a certain relationship between the time of anomaly occurrence and epicentral distance. The time of anomaly occurrence at stations near the epicenter is earlier than that at stations far away from the epicenter.
ZHANG Yan,ZHAO Ying,SHI Heqing et al. Analysis on Characteristics of Fixed Point Deformation Data before Yangbi M6.4 Earthquake in Yunnan Province[J]. jgg, 2022, 42(3): 221-224.
