中国大陆强震活动时空特征分析
|
摘要
本文在以往研究的基础上分析中国大陆强震活动的时空特征,以中国大陆1901年以来7级及其以上强震年频次为样本,采用最优分割将中国大陆地震活动状态分为三种时段:少发段、平均段和频发段。中国大陆强震时间活动呈现非稳态现象,强震频发段间存在短期的地震平静,由强震平均段到频发段过渡期间同样存在强震少发段,而少发段也有7级以上强震发生。以此为基础结合中国大陆活动地块边界带,研究不同强震丛发时段前地震活动的空间分布特点以及强震丛发时段的主体活动地区。研究结果表明,1901年以来中国大陆强震活动总体来讲,1955年前后表现出不同的空间特征:1955年之前强震活动主体区域为中国西部及周边大三角地区的三条边界;1955年之后强震活动主体区域为华北地区、巴颜喀拉地块区及南北地震带南段地区。不同相邻强震丛发时段的主体活动地区有一定的交替性,少发时段或增多时段的强震往往是上一个丛发时段的主体区内强震活动的延续,或者发生在下一个强震主体活动区内或周边地区。
Based on analysis of the temporal and spatial characteristics of strong earthquake activities in mainland China,this paper studies the M≥7 earthquakes in mainland China from 1901 by Fisher method.The states of strong earthquake activities can be divided into intermittent phase,sporadically occurring phase and frequently occurring phase.Then based on this division,we discussed the spatial characteristics of earthquakes before one frequently occurring phase and the main area of strong earthquakes of the frequently occurring phase.The result indicates that there is an obvious difference of temporal and spatial characters of strong earthquake activities between the period of time before 1955 and after 1955.Before 1955,the duration of intermittent phases is shorter and the duration of frequently occurring phases is longer,and the main activity areas are the borderlines of the big triangle including the west of mainland China and its circumjacent areas.On the other hand,after 1995,the duration of intermittent phases is longer and the duration of frequently occurring phases is shorter,and the main activity areas are Huabei,the South-north earthquake belt,the Bayankala block.The main areas of different frequently occurring phase are alternant.The strong earthquakes of intermittent phase and sporadically occurring phase sometimes occurred in the main area of last frequently occurring phase or correlative with the main area of next frequently occurring phase.
Based on analysis of the temporal and spatial characteristics of strong earthquake activities in mainland China,this paper studies the M≥7 earthquakes in mainland China from 1901 by Fisher method.The states of strong earthquake activities can be divided into intermittent phase,sporadically occurring phase and frequently occurring phase.Then based on this division,we discussed the spatial characteristics of earthquakes before one frequently occurring phase and the main area of strong earthquakes of the frequently occurring phase.The result indicates that there is an obvious difference of temporal and spatial characters of strong earthquake activities between the period of time before 1955 and after 1955.Before 1955,the duration of intermittent phases is shorter and the duration of frequently occurring phases is longer,and the main activity areas are the borderlines of the big triangle including the west of mainland China and its circumjacent areas.On the other hand,after 1995,the duration of intermittent phases is longer and the duration of frequently occurring phases is shorter,and the main activity areas are Huabei,the South-north earthquake belt,the Bayankala block.The main areas of different frequently occurring phase are alternant.The strong earthquakes of intermittent phase and sporadically occurring phase sometimes occurred in the main area of last frequently occurring phase or correlative with the main area of next frequently occurring phase.
引文
[1]洪时中.最优分割在地震分期中的应用[J].西北地震学报,1984,6(1):49-57.
[2]傅征祥,程燕.中国大陆近代幕式地震活动的某些特征[J].地震,1986,6(2):28-35.
[3]邱竞男.关于本世纪我国地震活动阶段性的讨论[J].地震,1986,6(4):41-47.
[4]张国民.我国大陆强震活动的韵律性特征[J].地震地质,1987,9(2):27-37.
[5]张国民,马宏生.我国陆区7级地震形势分析[A].中国地震局地震预测研究所.中国大陆强震趋势预测研究(2007年度)[C].北京:地震出版社,2006.59-64.
[6]马宏生,邵志刚,周龙泉,等.中国大陆7级地震活动状态分析[J].地震,2008,28(3):8-13.
[7]方开泰,潘恩沛.聚类分析[M].北京:地质出版社,1982.
[8]杨向东,秦乃岗.使用有序样品聚类分析法划分东南沿海地震活跃幕[J].华南地震,2004,24(2):55-61.
[9]国家地震局震害防御司.《中国历史地震目录》[M].北京:地震出版社,1995.
[10]中国地震局震害防御司.《中国近代地震目录》[M].北京:地震出版社,1999.
[11]时振梁,赵荣国,王淑贞,等.《世界地震目录》[M].北京:地图出版社,1986.
[12]时振梁,汪良谋,傅征祥,等.中国大陆中长期强震危险性预测方法研究[M].北京:海洋出版社,1997.
[13]张国民,马宏生,王辉,等.中国大陆活动地块边界带与强震活动[J].地球物理学报,2005,48(3):602-610.
[2]傅征祥,程燕.中国大陆近代幕式地震活动的某些特征[J].地震,1986,6(2):28-35.
[3]邱竞男.关于本世纪我国地震活动阶段性的讨论[J].地震,1986,6(4):41-47.
[4]张国民.我国大陆强震活动的韵律性特征[J].地震地质,1987,9(2):27-37.
[5]张国民,马宏生.我国陆区7级地震形势分析[A].中国地震局地震预测研究所.中国大陆强震趋势预测研究(2007年度)[C].北京:地震出版社,2006.59-64.
[6]马宏生,邵志刚,周龙泉,等.中国大陆7级地震活动状态分析[J].地震,2008,28(3):8-13.
[7]方开泰,潘恩沛.聚类分析[M].北京:地质出版社,1982.
[8]杨向东,秦乃岗.使用有序样品聚类分析法划分东南沿海地震活跃幕[J].华南地震,2004,24(2):55-61.
[9]国家地震局震害防御司.《中国历史地震目录》[M].北京:地震出版社,1995.
[10]中国地震局震害防御司.《中国近代地震目录》[M].北京:地震出版社,1999.
[11]时振梁,赵荣国,王淑贞,等.《世界地震目录》[M].北京:地图出版社,1986.
[12]时振梁,汪良谋,傅征祥,等.中国大陆中长期强震危险性预测方法研究[M].北京:海洋出版社,1997.
[13]张国民,马宏生,王辉,等.中国大陆活动地块边界带与强震活动[J].地球物理学报,2005,48(3):602-610.
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