西南太平洋地区地震序列的特征
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摘要
共搜集到 1984～ 1990年西南太平洋地区 12个板缘地震序列。多数地震序列的特征是 :震中分布区域的长轴较长并且随主震震级和序列中强震次数而增加 ;震中分布区域的长、短轴长度的比值较高 ;地震序列的余震震源机制和主震的差异不大 ;震源深度下限超过地壳 ,可达 70km以上。走滑型主震占的比例低 ,高倾角滑动面的走向既有与俯冲带走向平行的也有横切的 ,个别逆冲型地震的断层面走向横切俯冲带。它们显示出与板块俯冲带主体特征不同的现象
Collected 12 examples of plate boundary earthquake sequences of Southwestern Pacific from 1984 to 1990. The features of most of the sequences are as below: the major axis of the epicenter area is longer,and increased with magnitude of the mainshock and mount of strong aftershocks,the ratio of the major axis to minor axis is larger; focal mechanism solutions of aftershocks are not significantly different to the solution of mainshock in a sequence; the deepest focus below the crust bottom can be at 70km or more.Percentage of strike-slip type mainshock is low. Some fault plane strikes of dip-slip type are parallel to the trend of subduction zone,and some are perpendicular to it.Fault planes strikes of a few reverse-slip type are perpendicular to the trend of subduction zone.They showed that different phenomena from fundamental feature of earthquake sequences in the plate subduction zone.
Collected 12 examples of plate boundary earthquake sequences of Southwestern Pacific from 1984 to 1990. The features of most of the sequences are as below: the major axis of the epicenter area is longer,and increased with magnitude of the mainshock and mount of strong aftershocks,the ratio of the major axis to minor axis is larger; focal mechanism solutions of aftershocks are not significantly different to the solution of mainshock in a sequence; the deepest focus below the crust bottom can be at 70km or more.Percentage of strike-slip type mainshock is low. Some fault plane strikes of dip-slip type are parallel to the trend of subduction zone,and some are perpendicular to it.Fault planes strikes of a few reverse-slip type are perpendicular to the trend of subduction zone.They showed that different phenomena from fundamental feature of earthquake sequences in the plate subduction zone.
引文
1 李钦祖 ,BoltBA . 1979年美国加州凯奥蒂湖地震序列震源机制分析 :美国加州地震比中国大陆地震破裂过程简单的证据 .地球物理学报 ,1992 ,35 (2 ) :16 0～ 173
2 金性春 .板块构造学基础 .上海 :上海科学技术出版社 ,1984.
3 ScholzCH .Themechanicsofearthquakesandfaulting .CambridgeUniversityPress ,1990 .
4 马宗晋 ,张德成 .板块构造与地震 .见 :李春昱 ,郭令智 ,朱夏编 .板块构造基本问题 .北京 :地震出版社 ,1986 ,36 3～ 391
5 ScholzCH ,AvilesC ,WesnouskyS .Scalingdifferencesbetweenlargeintraplateandinterplateearthquakes .Bull.Seismol.Soc .Am .,1986 ,76 :6 5～ 70
6 郑斯华 .西藏高原及其周围地区地震的地震矩张量及震源参数的尺度关系 .地震学报 ,1992 ,14(4 ) :42 3～ 434
2 金性春 .板块构造学基础 .上海 :上海科学技术出版社 ,1984.
3 ScholzCH .Themechanicsofearthquakesandfaulting .CambridgeUniversityPress ,1990 .
4 马宗晋 ,张德成 .板块构造与地震 .见 :李春昱 ,郭令智 ,朱夏编 .板块构造基本问题 .北京 :地震出版社 ,1986 ,36 3～ 391
5 ScholzCH ,AvilesC ,WesnouskyS .Scalingdifferencesbetweenlargeintraplateandinterplateearthquakes .Bull.Seismol.Soc .Am .,1986 ,76 :6 5～ 70
6 郑斯华 .西藏高原及其周围地区地震的地震矩张量及震源参数的尺度关系 .地震学报 ,1992 ,14(4 ) :42 3～ 434
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