1975年2月4日海城地震。
其他许多中国的大地震象海城地震一样，也有类似的前兆震群。
Many other violent earthquakes sofar occurred in China, similar to the Haicheng earthquake, also had precursory earthquake swarms.
本文总结了海城地震的中期、短期和临震阶段的地倾斜异常特征。
In this paper, the medium-range, short-range and imminent earth-tilt anomalies before the Haicheng earthquake are examined.
应用推荐