从能量及地质条件探讨主-余震型地震序列活动的特征

一、前言观测表明,在地壳形变区域中,如果发生一次较大的地震,那么由主震所激发而与主震有关的余震便立即进行活动,余震释放能量的总和与主震释放能量的比值,取决于地震序列活动的类型、根据我国境内6.0级以上地震统计的研究,大致分为下列几种类型。1.孤立型这种类型的地震序列活动,其能量基本上通过主震一次释放;前震和余震能

A STUDY OF THE CHARACTERISTICS IN MAJOR-AFTER SHOCK TYPE BASED ON ENERGY AND GEOLOGICAL CONDITIONS.

Generally Speaking, there are three types in the seismic activities. One of them is usually the type of major-after shock. They are related to(1) The mode and the rate of the force;(2) The physical characteristics of the rocklayer and the geological conditions in the focus region.In this papcr we have discussed the characteristics from the viewpoint of energy ang based on geological conditions. It shows that the major-after shock activities usually occur in the second order tectonics connected with the major-fault.The volume of the aftershock may be regarded as a region which has been deformed. The product of the critical value of the strain energy per unit volume in the rock and the after-shock volume is in the same order as the energy released by the major-shock.We may calculate the strain value of the fracture from the strain energy pcr unit volume.It is smaller than the value based on geodesy.