摘要
依据沿近于EW向的燕山断陷带附近的定点形变观测结果，讨论了异常区域分布的动力学特征。结果表明：①在燕山北部块体上的EW向倾斜在震前1年时间尺度内保持相对静止，而NS向则向南加速倾斜，震前0．5年在附近台站出现回跳；②同一测点处二个方向倾斜的发散度在震前2年内出现相似的运动特征，呈减弱趋势；③同一块体不同测点处的异常强度AF值在震前3年间至少出现2次较显著的异常标志。
Based on the results of tilting observation in the fault depression of Yanshan mountain,this paper discussed the dynamic features of anomalies in the depression and boundary area. It was demonstrated as follows:①The relative quiet of tilting along the EW direction and the speeding of tilting toward S along NS direction have been shown one year before Zhangbei Ms 6. 2 earthquake, and the sudden rebound of tilting along the NS direction before a half-year has also been detected in the region close to the epicenter;②The divergence of tilting along the EW and NS directions shows the synchronous movement feature with decreasing tendency two years before the earthquake;③At least two times of obvious anomalous marks expressed by the anomaly intensity AF have been shown at sites in the depression.
出处
《地震》
CSCD
北大核心
1998年第4期373-377,共5页
Earthquake
基金
地震科学联合基金!197066
关键词
张北地震
定点倾斜观测
动力学
地震前兆
Zhangbei earthquake，Tilting observation at the fixed sites, Divergence and anomaly intensity
