内应力模式震前蠕裂感生的前兆特征

已有的前兆模型大体上可分两类:一类从完整岩石的破裂试验为基础,得出破裂区（震中）附近完全一致的前兆曲线;另一类以数理理论为基础,推得震源区附近有力学性质不同的区域,而同一性质的区域有与构造应力同步的前兆曲线。由于它们的前提与实际情况有较大的差异,没有考虑孕震区中原有裂纹的存在,这些前兆模型似不能很好地说明许多震例中的复杂的前兆现象。本文在“构造地震的局部内应力源模式”和“失稳破裂与蠕裂”两文的基础上,进一步讨论由于震前蠕裂所产生的应力场的时空变化而感生的前兆特征。

THE CHARACTERS OF PRECURSORY PHENOMENA DUE TO THE CREEP FRACTURE BEFORE EARTHQUAKES ACCORDING TO THE LOCAL INTERNAL STRESS MODEL

On the basis of the papers "A local internal stress model of tectonic earthquake" and ' The creep fracture and instaJble fracture',this paper deals with the characters of precursory phenomena due to the creep fracture before earthquakes,that is,the precursory shape caused by the variation of elastic stress field surrounding the crack when creep fracture happens. The result shows that the precursory phenomena are too complex that it is difficult to predict earthquake by them.