FOCUS PROCESS OF TANGSHAN EARTHQUAKE-MAYBE EXISTING BARRIERS
Lu Zheng; Li Zhi-Tian ( Seismological office of Jilin Province )
Accoring to the data of focus parameters of the mainshock and strong af tershock and moving characterist of strong aftershocks and so on, we attempt to demoo, strate the existence of Fangshan earthquake barriers. The results show that the barriers are loceted in Ninhe and Lanxian- lulong faults. We consider the mainshock of Tangshan main fault barriar. The rupture of mainshock stoped because of resistance of barriers to be located in above faults. After mainshock the two regions forms new stress concentration area. These stress concentration regions gave rise to two largest aftershocks.