Abstract: In this paper,we introduce the measurements of crustal tilt using the Qionghai Observation System and a preliminary approach to the relation between the crustal plane tilt observed by the System and seismic activity in the region around the Qionghai Lake,at Xichang.The results show that the observed accuracy may reach the magnitude of 10^-7-10^-8 radian. The processes of the crustal stress accumulation and release are characterized by the activity of moderate earthquakes (M≥5.0) whose epicenters are located within a range away from the Qionghai Lake,and are reflected to a certain extent by time dependent processes of the crustal tilt observed by the System.The short-term and impending precursors of moderate earthquakes are similar to those of the great ones,featuring of trending and abrupt anomalies.

Key words: Crustal deformation, Xichang Qionghai, Seismic activity

摘要： 邛海地倾斜观测系统的测量结果表明:面倾斜观测精度可达10^-7至10^-8弧度;观测面倾斜的变化反映了邛海及其周围地区的,以M≥5.0地震活动为特征的地壳应力积累和释放过程;中强地震的短临前兆与大地震的趋势性和突发性两种前兆特征相似。

关键词: 地形变, 西昌邛海, 地震