1975年海城地震前地下水异常的时空分布

本文经过对1975年海城地震前大量的、约200处观测资料的地下水变化异常的发生时间与地点之间的关系的分析,发现1975年1月31日以前发生的地下水变化异常点是随着时间从外围(东西)以一定的速度向震中方向迁移的,日后到海城地震前,地下水异常点则又从震中向外围扩展。 将震前大量的地下水异常点观测资料的时间与地点这两个量进行回归分析,得知1975年1月31日以前的地下水异常点的逐渐向震中方向迁移是线性的。 笔者认为,震前地下水异常点具有上述规律性的时空分布过程,反应了震前地壳所受的力是由外围(东西)逐渐向震中方向传递及回返的。

TEMPORAL AND SPATIAL DISTRIBUTION OF ANOMALOUS GROUND WATER CHANGES BEFORE THE 1975 HAICHENG EARTHQUAKE

This paper deals with a study of an empirical relation between the times and locations of abnormal ground water changes observed before the Haicheng Earthquake of 1975, based on a large amount of data, about 200 observation points. It is found that the points of abnormal ground water changes migrated toward the epicen-tral area of the Haicheng Earthquake from the surroundings before January 31, 1975 with a definite velocity. After that until the outbreak of the earthquake they returned from the epicentral area very quickly.By means of regressional analysis of the times and locations of the anomalous ground water changes, it can be shown that prior to January 31, 1975 the relation between the times and locations is linear. It is also assumed that this relation reflects a possibility that before the Haicheng Earthquake the crust of the area was subjected to a stress which transmitted from the outer regions toward the epicentral area and then back.