摘要
2004年12月26日苏门答腊岛安达曼海附近海域发生的9.0级地震和2005年3月28日苏门答腊岛明打威群岛北附近海域的8.7级地震,在构造环境、震级、震源深度、地震类型都相似的情况下,为何前者引发海啸,后者不引发的海啸?对此进行了对比分析,认为9.0级地震发生时,在其震源体附近的两板块相交的海沟两侧陡坡蕴育着滑坡体或和崩塌体(或者两者都有),9.0级地震发生时,强烈的地震波,促使滑坡体的滑动或崩塌体的崩塌,推压和扰动海水,引发海啸。而8.7级地震发生时,在其震源体附近的两板块相交的海沟两侧陡坡无滑坡体或和崩塌体,或先存滑坡体或崩塌体在9.0级地震发生时已滑坡或崩塌殆尽,当8.7地震发生时,无滑坡体滑动或崩塌体崩塌,不可能对海水有较大的扰动,故不可能引发海啸.
One great earthquake occurred at Sumatra Andaman Sea, December 26th 2004 with a magnitude of M9.0, and the other one occurred at Sumatra Mentawai archipelago, March 28th 2005 with a magnitude of M8.7. With similar conditions such as seismotectonic environment, magnitude, hypocenter depth, earthquake type, why did the former cause tsunami, but the latter not？ After comparison and analysis, we find that when the M9.0 earthquake occurred, the intense seismic waves induced coast body gliding, collapse body collapsing and disturbed sea water, finally caused tsunami; whereas when the M8.7 earthquake occurred, there was no coast body or collapse body at the sea trench where two plates crossed near the hypocenter body, or the former existing coasting body and collapse body had disappeared after the M9.0 earthquake. Thus when the M8.7 earthquake happened, there was none coast body or collapse body that could generate great disturbing to sea water, and no tsunami occurred.
出处
《华南地震》
2008年第2期72-79,共8页
South China Journal of Seismology
关键词
海啸
板块
海沟
地震
滑坡体
震源类型
Earthquake, Tsunami, Collapse body, Plate, Sea trench, Hypocenter type
