【摘要】 <正> 1985年10月4日,我们根据易县台水平摆倾斜仪出现的前兆异常信息,向国家地震局分析预报中心值班室呈报如下预报意见: “易县台水平摆倾斜仪自9月下旬以来出现明显的北西方向陡变。东西向西倾0.″06,南北向北倾约0.″08。异常持续约8天。10月1日后已基本恢复正常。更多还原

【Abstract】 Based on the anomalous tilt observed at the crustal deformation observatory in Yi-xiau county, an experimental prediction of a moderate earthquake which might occur in North China was proposed to the agency concerned by the authors on October 4, 1985.On October 5, a moderate earthquake (ML=5.3) occurred at Shaheyi of the Tang-shan area in Hebei province. The prediction was successful.The characteristics of the anomalous changes recorded by the tiltmeter are analysed in this paper. Based on the method of graphic distinction and the calculation of the tidal factor, we consider that the tilt precursor was reliable and the prediction was reasonable.更多还原