唐山地震的震源过程——可能存在的障碍体

FOCUS PROCESS OF TANGSHAN EARTHQUAKE-MAYBE EXISTING BARRIERS

本文根据唐山主震、强余震震源参数、强余震迁移规律以及地面破坏分布等多方面资料,论证唐山地震障碍体的存在,给出了宁河、滦县—卢龙断层面上障碍体的大致位置.并用障碍体模式对唐山连发式强震的震源过程进行了讨论.笔者认为,唐山主震即是主震断层面上的障碍体破裂所致.主震断层的破裂传播在宁河、滦县—卢龙受阻于障碍体而终止,在这两处形成新的应力集中区.这两个应力集中区在障碍体的阻挡和主震区的挤压下产生两次最大强余震.

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.