印尼苏门答腊巨大地震活动特征
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摘要
主要使用了USGS全球地震查寻结果,对比研究了本世纪至今印尼苏门答腊地震的构造背景、巨大地震及其余震的活动特征,其主要结果如下:①巨大板块地震很少在原地重复发生,有迁移性和明显的填空特征;2000年之前的四次巨大地震具有明显向北迁移的特征,2000年之后三次巨大地震具有明显向南迁移和填空的特征;②2000年8.3级地震余震区南段存在约170 km的5级空段;③2004年9.0级地震余震填充了在巽他海沟东侧长约1 000 km的8级空段,其余震区南段存在约200 km的5级空段,沿板块边界形成的余震带具有明显向北迁移的特征;④2005年8.7级地震发生在2004年9.0级地震的200 km的余震空段上,余震分布不但填充了2000年8.3级地震170 km余震区5级空段,而且其余震区南段还存在约200 km和300 km的2个5级空段;⑤2007年8.5级地震发生在2005年8.7级地震约300 km余震空段的最南端,其7.9级最大余震发生在2005年8.7级地震约300km余震空段的最北端,使约300km余震空段的能量得到了充分释放;⑥2005年8.7级地震约200km余震区5级空段内的能量有可能还未得到释放,该地区是否还会发生一次巨大地震,还有待进一步研究。
The earthquake data we use in this paper from last century to now(2007) measuring over 5 Richter scale are got from the USGS world wide earthquake catalogs.The seismotectonic background,the active characters of the great earthquakes and its aftershocks distribution surrounding region of the great earthquake,off the west coast of northern Sumatra,Indonesian,are studied.The results of our work lead to the following conclusions:(1) no earthquake occurs again in the location where the first earthquake occurred in the intra-plate.The seismic epicenter migrates along the seismic faults and a new earthquake occurs in the seismic gap.For instance,after 4 great earthquakes before A.D.2000,the epicenters of its aftershocks migrated clearly northward.And after 3 great earthquakes after A.D.2000,the epicenters of its aftershocks migrated clearly southward and occurred in the seismic gap.(2) There is a seismic gap with 170 kilometer long in the south part of the aftershock area of the 2000 M8.3 Earthquake.(3) The aftershocks of the 2004 M9.0 Sumatra-Andaman Island Earthquake distributed on the seismic gap with 1000 kilometer long.There is a seismic gap on the southern part of aftershocks.The epicenter of the aftershocks distributed northward along the seismic faults.(4) The epicenter of the 2005 M8.7 Northern Sumatra Earthquake occurred in the seismic gap of the 2004 M9.0 Sumatra-Andaman Island with 200 kilometer long and distributed in the seismic gap of the 2000 M8.3 Southern Sumatra Earthquake with 170 kilometer long.Along the seismic belts,there are 2 seismic gaps with 200 and 300 long respectively.(5) The 2007 M8.5 Southern Sumatra Earthquake occurred in the most south end of the aftershock region after the 2005 M8.7 Northern Sumatra Earthquake.The maximum aftershock magnitude is M7.9 which occurred in the most northern end of the seismic gap of the 2005 M8.7 Northern Sumatra.Its seismic gap length is 300 kilometer.The aftershocks release the accumulated energy completely.(6) In the seismic gap with 200 kilometer long after the 2005 M8.7 Northern Sumatra Earthquake,the part of accumulated energy was released.So weather there will be another earthquake is to be discussed later.
The earthquake data we use in this paper from last century to now(2007) measuring over 5 Richter scale are got from the USGS world wide earthquake catalogs.The seismotectonic background,the active characters of the great earthquakes and its aftershocks distribution surrounding region of the great earthquake,off the west coast of northern Sumatra,Indonesian,are studied.The results of our work lead to the following conclusions:(1) no earthquake occurs again in the location where the first earthquake occurred in the intra-plate.The seismic epicenter migrates along the seismic faults and a new earthquake occurs in the seismic gap.For instance,after 4 great earthquakes before A.D.2000,the epicenters of its aftershocks migrated clearly northward.And after 3 great earthquakes after A.D.2000,the epicenters of its aftershocks migrated clearly southward and occurred in the seismic gap.(2) There is a seismic gap with 170 kilometer long in the south part of the aftershock area of the 2000 M8.3 Earthquake.(3) The aftershocks of the 2004 M9.0 Sumatra-Andaman Island Earthquake distributed on the seismic gap with 1000 kilometer long.There is a seismic gap on the southern part of aftershocks.The epicenter of the aftershocks distributed northward along the seismic faults.(4) The epicenter of the 2005 M8.7 Northern Sumatra Earthquake occurred in the seismic gap of the 2004 M9.0 Sumatra-Andaman Island with 200 kilometer long and distributed in the seismic gap of the 2000 M8.3 Southern Sumatra Earthquake with 170 kilometer long.Along the seismic belts,there are 2 seismic gaps with 200 and 300 long respectively.(5) The 2007 M8.5 Southern Sumatra Earthquake occurred in the most south end of the aftershock region after the 2005 M8.7 Northern Sumatra Earthquake.The maximum aftershock magnitude is M7.9 which occurred in the most northern end of the seismic gap of the 2005 M8.7 Northern Sumatra.Its seismic gap length is 300 kilometer.The aftershocks release the accumulated energy completely.(6) In the seismic gap with 200 kilometer long after the 2005 M8.7 Northern Sumatra Earthquake,the part of accumulated energy was released.So weather there will be another earthquake is to be discussed later.
引文
[1]薛艳,刘杰,等.印尼苏门答腊两次巨大地震序列特征的对比分析[J].国际地震动态,2005,(10).
[2]国家地震局震害防御司编译.全球重大灾害性地震目录(2150B.C.—1991A.D.)[M].北京:地震出版社,1996,108-109.
[2]国家地震局震害防御司编译.全球重大灾害性地震目录(2150B.C.—1991A.D.)[M].北京:地震出版社,1996,108-109.
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