我国许多大震前的短临前兆具有突跳性质。由于它易于觉察,所以具有重要意义,但其成因还未确定。我们试图以“液压破裂”观点来解释这个现象。如所周知,在地壳浅层具有储存流体的构造、裂隙和孔隙。有的液体将封闭其内,有的可以渗流泄走,称为非圈闭体。在圈闭体内,平时一般有较高的孔隙压力。非圈闭 The short precursory precursors to many large earthquakes in our country have the sudden jump nature. It is of great importance because of its ease of detection, but its cause has not yet been determined. We try to explain this phenomenon from a “hydraulic fracture” point of view. As is well known, there are reservoirs in the shallow crust, fractures and pores. Some liquid will be closed inside, and some can leak seepage, known as the non-trap body. In the trap body, usually have a higher pore pressure. Non-trapping