THE DIFFERENCE BETWEEN STRAIN PRECURSORS WITHIN SEISMIC SOURCE AND SEISMIC FIELD REGIONS AND ITS APPLICATION TO EARTHQUAHE PREDICTION
Li Qicheng(Earthquake Recoarch Institute of Lanzhou,SSB,Lanzhou, 730000)
In this paper,on the basis of the combination pattern,author caculates two models byusing the 3-D finite element method. The major conclusions are :(1)The adjustment elementfractures firstly before the strong earthquake takes place,variation of strain with time is aquasi-lambda curve.(2)The accumulative element will fracturc after the adjustment elementfractures,variation of strain with time is a lambda curve.(3)The strain attenuates quicklyalong thc perpendicular direction of fault strikc,but slowly aiong the fault strike.(4)The situa-tions of the clements in a seismic field region are very complex,and their strain changes withtime are non-lambda curves. Finally,some seismic events about lambda-pattern are presented,and some precursory phenomena are interpreted by using conclusion(1).