构造地震的局部内应力源模式

本文根据断层在孕震过程中伴随有蠕动这一事实, 利用裂隙位错的数学理论, 提出了一个新的构造地震的震源模式——局部内应力源模式, 其特点是强调了在区域应力场基本不变的条件下因断层蠕动产生的局部内应力在孕震过程中的作用.文中推导了内应力随时间的变化及由此产生的二维准静态应力场和裂端塑性区线度, 并据此对强震前可能出现的前兆异常的时空特征作了估计.

A LOCAL INTERNAL STRESS MODEL OF TECTONIC EARTHQUAKES

Based on the fact that the process of development of an earthquake is usually accompanied by fault creeps, a new mechanical model——the local internal stress modelfor tectonic earthquakes is proposed here by means of the mathematical theory of crack dislocation. It emphasizes the effect of the local internal stress caused by fault creeps in the process of development of an earthquake when the regional stress field is kept essencially constant. Change of internal stress with time and a two-dimensional quasi-static stress field thus given rise and the dimensions of the plastic zone beyond the tip of the crack are derived. The time and space characteristics of the premonitory anomalies before the occurrence of strong earthquakes are discussed.