摘要
对断裂带活动性与重力变化关系的研究,过去一般采用研究断裂带上的实测重力段差值随时间、空间变化特征来实现。但由于受某些条件的制约,目前供该项研究的实测重力段差值在数量上远远满足不了需要。因此,本文提出一种弥补上述不足的方法:采用计算跨活动断裂带两重力点间的差值来代替实测重力段差值。 作者用该方法对北京地区十几年的重力复测成果进行了处理后指出:在唐山地震前后,该区跨北北东和北西向断裂带上部分测段有100×10^(-8)m/s^2左右的重力变化,且跨北西向断裂带的重力变化较北北东向上的明显。重力场的这一空间与时间分布特征为用重力复测手段预报强震发震的时间与地段提供了依据。
So far many studies on the relationship between active tectonics and gravity field were made only by utilizing the features that gravity observations changed with time and areas. But the amount of segment gravities is far less than wanted in analyzing. For this reason, a new method was put forward to remedy this deficiency:Using apparent segment gravity between two gravity stations crossing fracture belt, which was calculated by deducing gravity from other gravity station, displace the real one.By handling with the repeated gravity data of ten more years in Beijing area in this way, we found that about 100μgal of gravity change existed in part of the observed lines along both the NNE and the NW fracture belts around Tangshan earthquake,and the gravity change in the line crossing the NW fracture belt is more obvious than that in the line crossing the NNE fracture belt.The spatial and temporal features of gravity field provide an evidence for predicting the occurrence and site of a strong earthquake by means of repeated gravity measurements.
出处
《地壳形变与地震》
CSCD
1990年第4期15-24,共10页
Crustal Deformation and Earthquake
