地下流体的源兆,场兆,远兆及其在地震预报中的意义

我国地震地下流体监测网中，发现强震前有３种不同的前兆异常，即来自震源的源兆异常、与地震有关的区域活动关联的场兆异常及远距离强震前出现的远兆异常，它们在成因、特征与地震预报实践中的意义不同。从数量上看，场兆是大量的，源兆是少量的，而远兆也是不可忽略的。因此，地震预报实践中，必须正确地区别这３种前兆，全力寻找源兆，积极地开发场兆的预报功能，承认远兆并揭示其科学意义。

THE FOCAL PRECURSORS, FIELD PRECURSORS AND REMOTE PRECURSORS OF GROUND FLUID BEFORE STRONG EARTHQUAKES AND THEIR SIGNIFICANCE IN THE EARTHQUAKE PREDICTION

There are three different precursors of ground fluid before strong earthquakes inChinese ground fluid monitoring network. The focal precursors are originated from a fo-cus, the field precursors produced by a regional tectonic activity related to anearthquake, and the remote precursors are appeared before a remote distanceearthquake. They are different in the origin, the characteristics and significance in thepractice of earthquake prediction- From the viewpoint of quantity, the field precursorsare larger, the focal precursors are smaller, and the remote precursors can beneglected. Therefore, in the practice of earthquake prediction, we must explore the focalprecursors in full, must excavate the prediction function of the field precursors, and mustadmit the remote precursors and recognized its scientific significance.