1985年3月29日19时15分,在自贡北东发生4.6级地震,其震源浅(震源深度7千米),烈度高(震中烈度达Ⅷ度),破坏大,给自贡市人民生命财产造成较大损失。对这次地震事前未作预报,现有必要回头总结可能存在的异常现象,以利于今后的预测预报工作。在为数不多的存在异常的手段中,以地下水位变化比较突出。在距震中80千米范 At 19:15 on March 29, 1985, a 4.6-magnitude earthquake hit the east of Zigong with a shallow focal depth (focal depth of 7 km) and high intensity (epicenter intensity of Ⅷ degree), which greatly damaged the lives and property of people in Zigong City Cause greater loss. Without forecasting the earthquake in advance, it is necessary to go back and summarize the possible anomalies so as to facilitate future forecasting and forecasting work. Among the few means of anomalies, changes in the groundwater level are more prominent. 80 km from the epicenter