1998年张北6.2级地震宏观烈度
|
摘要
充分利用震害评估和宏观考察的资料 ,采用震害程度和震害指数 2个标准共同确定了1 998年张北 6.2级地震的宏观烈度。极震区烈度为 度 ,呈 NWW和 NNE双向分布 ,以NWW为主 ,面积 1 35km2 。 度区呈 NE、NW双向伸展图象 ,但是 SE方向伸展不足 ,面积约340 km2。地震重伤人员普遍集中在 度区和 度区。 度区亦呈 NE、NW双向伸展图象 ,但是 NW、SW方向延伸长 , 度区面积约 1 0 0 0 km2 。宏观震中 :北纬 41°0 9′,东经 1 1 4°2 7′。在极震区的 NNE、SSW和 NWW方向 ,存在 3个烈度异常区 ,它们分别在极震区 3个分支的延伸方向上。文中讨论了烈度不高而震后较重的原因。震区没有发现地表破裂带 ,也没有发现第四纪强烈活动的大型断裂。极震区为主的 NWW方向和震前存在的小地震条带吻合 ,暗示可能存在成因上的联系
Based on earthquake damage assessment and macro observation,the macrointensity of Zhangbei M s6.2 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 135km 2.The Ⅶdegree region stretches NE and NW two directions with an area of 340km 2,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 1000km 2,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.
Based on earthquake damage assessment and macro observation,the macrointensity of Zhangbei M s6.2 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 135km 2.The Ⅶdegree region stretches NE and NW two directions with an area of 340km 2,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 1000km 2,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.
引文
[1 ] 徐锡伟、冉勇康、周本刚等 .张北—尚义地震的地震构造环境与宏观破坏特征 .地震地质 ,1 998,2 0 ( 2 ) :1 35-1 4 6.
[2 ] 中国地震局 .地震现场工作大纲和技术指南 .北京 ;地震出版社 ,1 998,1 1 1 -1 1 4 .
[3] 刁桂苓 ,张四昌 ,朱艾谰 .张北 6.2级地震发生在小震条带上 .华北地震科学 ,1 998,1 6( 3) :34 -38.
[2 ] 中国地震局 .地震现场工作大纲和技术指南 .北京 ;地震出版社 ,1 998,1 1 1 -1 1 4 .
[3] 刁桂苓 ,张四昌 ,朱艾谰 .张北 6.2级地震发生在小震条带上 .华北地震科学 ,1 998,1 6( 3) :34 -38.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心