THE MACROINTENSITY OF ZHANGBEI MS6.2 EARTHQUAKE IN 1998

Diao Guiling; Cai Huachang; Diao Jianxin; Zhao Jun; Huang Wanfa

doi:10.3969/j.issn.1003-1375.2001.01.004

Abstract：Based on earthquake damage assessment and macro-observation,the macrointensity of Zhangbei Ms6.2 earthquake is determined with the 2 criterion of damage degree and index.The intensity of meizoseismal region is Ⅷ degree.The distribution is along NWW and NNE two directions,but mostly in NWW direction.The area of the meizoseismal region is about 135km2.The Ⅶdegree region stretches NE and NW two directions with an area of 340km2,but the SE direction doesn't stretch enough.The wounded people concentrated mostly in Ⅷ and Ⅶ degree rgeion.The Ⅵ degree region stretches along NE and NW direction with an area of 1000km2,but the NW and SW direction stretches larger.The macroseismic epicenter is about 41°09′N，114°27′E.There are three anomalous intensity areas,which located in the three offsets that the meizoseismal region stretches.The reason that intensity isn't high but damage is serious is discussed here.Neither surface fault nor great active fault of alluvium period is found in the quake region.The main direction of NWW for meizoseismal region is consistent with a small earthquake belt appeared before the event,which hints some causes relations.