大震前宏观异常的机理研究

Study on the Mechanics of Macro Abnormal Phenomena before Great Earthquakes

摘要:

主要通过对1975年海城地震前出现的宏观异常现象的分析,推测大震前在震源区的地下岩体中就已产生了贯通到近地面的规模不等的宏观裂缝,在构造应力场的持续作用下裂缝会进一步的扩张、错动和贯通形成更大规模的裂缝。而发震断层实际上是主震前沿发震断裂上的裂缝最后一次扩张、错动和贯通的结果。论证了大震之前这些裂缝的进一步的扩张以及沿这些裂缝热物质的上涌导致了震前形式多样的各种宏观前兆现象的产生。

Abstract:

By investigating the various macro abnormal phenomena mainly before Haicheng earthquake in 1975, it is deduced that there are many rifts of different size underground in epicentral region before a great earthquake. These rifts can be found on the surface sometimes. Under the sustainable action of tectonic stress field, the expansion, dislocation and joint within or between these rifts will produce new rifts with greater size. The seismic fault, which was seen after the main shock, is the result of the last expansion, dislocation and joint of the rifts along the fault before the main shock. It is the expansion of these rifts and hot fluid moving up along them cause the various forms of macro abnormal phenomena before a great earthquake.