关键词: 汶川地震, 极震区, 宏观震中

Abstract: The M_S8.0 Wenchuan earthquake is one of the most devastating earthquakes in recent 30 years in the world.Based on a number of on-the-spot investigations,preliminary research on the macro-epicenter and meizoseismal region has been done.The analysis reveals that the meizoseismal region,whose intensity is Ⅺ and shows obviously zonal distribution,is controlled by the rupture process and there exists a close relationship between the meizoseismal region and the rupture zone.What's more,the macro-epicenter of Wenchuan Earchquake is quite different from those of previous earthquakes,not just one point any more but a group of points.This group of points begins from the village of Caijiagang of Xuankou town of Wenchuan county,passes through Yingxiu town,Yinxing town of Wenchuan county,the north of Hongkou town of Dujiangyan city,the north of Xiaoyudong town and Longmenshan town of Pengzhou city,the north of Hongbai town of Shifang city,and ends at Qingping town of Mianzhu city.Skipping over Anxian county,it continues from Leigu town of Beichuan county to Xuanping town,Qushan town,Chenjiaba town,Pingtong town of Pingwu county,and ends at the north of Nanba town.The shape of the macro-epicenter area of the Wenchuan earthquake can be considered as a narrow belt or line,broken in the middle.This point of view will influence our overall understanding of quake-hit areas to a great extent.Besides,the realization that the macro-epicenter of a severe earthquake probably presents like a line is of great significance when we cope with severe earthquakes later,especially when determining key relief areas,planning the relief work,evaluating the earthquake situation,identifying key areas of scientific investigation and so on.

Key words: Wenchuan earthquake, the meizoseismal region, the macro-epicenter