华南地震区的某些丛集特性
|
摘要
对东南沿海地区54次中强以上地震(MS≥43/4级以上地震)的时间间隔序列,计算了时间变异系数δ值,利用δ值研究地震的丛集特性;从1943年至今的时间变异系数计算结果为1.2,说明该时间段明显处于丛集状态。对东南沿海地震带通过有序样品序列聚类分析得出了较为合理四个地震活跃幕的划分结果,各个活跃幕地震的累积频次与发震系统内部时间的关系基本符合N=ctd。四个活跃幕的非线性时间结构演化幂指数d变化范围分布在0.6到0.8左右。MS6.0以上的强震也基本符合该关系式。只是其活跃幕演化幂指数d为0.47。
There are earthquake crowed together-'cluster' phenomena distributed on the time axis on the China southeast coastal seismic belt,that were some seismic active periods alternated quiet periods since the 20th century.Using the time-frame variation coefficient method,we discussed some characteristics of the series.Using the ordered samples sequence cluster analysis method on 54 earthquakes occurrence time interval series,we obtained that dividing result of 4 active seismic episodes is more reasonable.Considering another parameter of the earthquakes occurrence time interval :time-frame variation coefficient δ,the calculate result(1.2) of southeast coastal seismic belt above moderate earthquake series(MS≥43/4) since 1943 indicate that is in earthquake cluster situation obviously from that time.For the 4 active episodes in each of them,the accumulate number of earthquakes vs.the earthquakes occurrence time accord with the formula N=ctd.The evolution power exponent d changed from about 0.6to 0.8,the accumulate number of strong earthquakes(M≥6.0)accord with the formula too,but its power exponent d is 0.47.
There are earthquake crowed together-'cluster' phenomena distributed on the time axis on the China southeast coastal seismic belt,that were some seismic active periods alternated quiet periods since the 20th century.Using the time-frame variation coefficient method,we discussed some characteristics of the series.Using the ordered samples sequence cluster analysis method on 54 earthquakes occurrence time interval series,we obtained that dividing result of 4 active seismic episodes is more reasonable.Considering another parameter of the earthquakes occurrence time interval :time-frame variation coefficient δ,the calculate result(1.2) of southeast coastal seismic belt above moderate earthquake series(MS≥43/4) since 1943 indicate that is in earthquake cluster situation obviously from that time.For the 4 active episodes in each of them,the accumulate number of earthquakes vs.the earthquakes occurrence time accord with the formula N=ctd.The evolution power exponent d changed from about 0.6to 0.8,the accumulate number of strong earthquakes(M≥6.0)accord with the formula too,but its power exponent d is 0.47.
引文
[1]时振梁,环文林,曹新玲,等.中国地震活动的某些特征[J].地球物理学报,1974,17(1):2-3.
[2]陆远忠,陈章立,王碧泉,等.地震预报的地震学方法[M].地震出版社1985,18.
[3]马宗晋,傅征祥,张郢珍,等.1966-1976年中国九大地震[M].北京:地震出版社,1982.189.
[4]林纪曾.东南沿海地区地震形势的探讨[J].华南地震,1983,3(增刊):1-10.
[5]任振寰,罗振暖,秦乃岗.华南地震区地震活动基本特征与地震大形势再研究[J].华南地震,1998,18(1):40-49.
[6]方开泰,潘恩沛.聚类分析[M].地质出版社,1982.
[7]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):49-56.
[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]Kagan,Y.Y.and D.D.Jackson,1991,Long-term earthquake clustering,Geophys.J.Int.,VoL.104,pp,.117-133.
[10]罗灼礼,孟国杰,王伟君,等.地震活动涨落、自组织结构和大震临界状态的统计特征[J].地震,2004,24(4):1-16.
[2]陆远忠,陈章立,王碧泉,等.地震预报的地震学方法[M].地震出版社1985,18.
[3]马宗晋,傅征祥,张郢珍,等.1966-1976年中国九大地震[M].北京:地震出版社,1982.189.
[4]林纪曾.东南沿海地区地震形势的探讨[J].华南地震,1983,3(增刊):1-10.
[5]任振寰,罗振暖,秦乃岗.华南地震区地震活动基本特征与地震大形势再研究[J].华南地震,1998,18(1):40-49.
[6]方开泰,潘恩沛.聚类分析[M].地质出版社,1982.
[7]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):49-56.
[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]Kagan,Y.Y.and D.D.Jackson,1991,Long-term earthquake clustering,Geophys.J.Int.,VoL.104,pp,.117-133.
[10]罗灼礼,孟国杰,王伟君,等.地震活动涨落、自组织结构和大震临界状态的统计特征[J].地震,2004,24(4):1-16.
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