云南地区M≥6.8强震活跃期首发地震前中强地震活动特征
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摘要
云南地区M≥6.8强震活跃期首发地震具有强度大、破坏重、影响广的特点。为深入剖析M≥6.8强震平静期中强地震活动特征,捕捉活跃期首发地震预测信息,研究了云南20世纪以来4个强震活跃幕的基本特征;根据平静期中强地震时经、时纬动态变化的有序迁移,以平静期6级首发、结束地震为参照,将平静期划分为调整、迁移、平静三个阶段,提出平静期比活跃期长以及6级地震的指示意义等活跃期首发强震的震前特征,同时提出预测标志以及平静期中青藏块体对云南SSE向侧向挤压是主要动力源等新观点,为首发强震的预测、短临跟踪提供了依据。
The first shock in the active period of M≥6.8 strong earthquakes in Yunnan usually has such features as large strength, heavy destroy and wide influence. In order to deeply analyze the moderate seismicity characteristics in the peace period of M≥6.8 strong earthquakes and capture the precursory information of the first strong shock, we studied four active episodes of strong earthquake since the 20th century in Yunnan. According to the migration routes of moderate shocks in the peace periods along longitude and latitude with time, we took M 6 initial and end earthquakes as indication, divided every peace period into three stages of adjustment, migration and peace and put forward some pre-earthquake features of the first strong shock, for example, longer peace period than active one, the sign of M6 earthquake, etc. Meanwhile, we suggested that the lateral extrusion of the Qinghai-Tibet block toward Yunnan in SSE direction was the main dynamic source of seismicity in Yunnan. Above motioned can supply the basis for strong earthquake prediction and short-term and impending-earthquake track.
The first shock in the active period of M≥6.8 strong earthquakes in Yunnan usually has such features as large strength, heavy destroy and wide influence. In order to deeply analyze the moderate seismicity characteristics in the peace period of M≥6.8 strong earthquakes and capture the precursory information of the first strong shock, we studied four active episodes of strong earthquake since the 20th century in Yunnan. According to the migration routes of moderate shocks in the peace periods along longitude and latitude with time, we took M 6 initial and end earthquakes as indication, divided every peace period into three stages of adjustment, migration and peace and put forward some pre-earthquake features of the first strong shock, for example, longer peace period than active one, the sign of M6 earthquake, etc. Meanwhile, we suggested that the lateral extrusion of the Qinghai-Tibet block toward Yunnan in SSE direction was the main dynamic source of seismicity in Yunnan. Above motioned can supply the basis for strong earthquake prediction and short-term and impending-earthquake track.
引文
[1]刘祖荫,苏有锦,秦嘉政,等.20世纪云南地震活动[M].北京:地震出版社,2002.
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