Preliminary study on coseismic step-like changes of water-level in the Dazhai well, Simao city, Yunnan Province

The study on coseismic step-like changes of water-level is of theoretical and practical significance to the mitigation of secondary hazards, identification of earthquake precursors, tracking of the subsequent shocks, and the research of crustal activity (Nur and Booker, 1972; WANG et al, 1988). A lot of researches have been done by previous geoscientists. Among them, ZHANG et al (1994) inverted stress variation in the aquifers through the analysis of coseismic step-like changes of well water level. LI (1995), WANG (2000), and FU et al (2002) studied the relationship between coseismic step-like changes of water level and future seismic activity. HUANG et al (2000) investigated the water-level changes in many wells after the occurrence of one great earthquake. However,the analysis of the quantitative relation between the coseismic step-like changes of water level and earthquakes in China has not been reported so far. This paper describes the coseismic step-like changes of water level in the Dazhai well, Simao city, Yunnan Province, and tries to discuss the possible mechanism of these changes.