| 全球大震活动特征 |
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| 引用本文： | 薛艳,刘杰,尹继尧,宋治平.全球大震活动特征[J].地球科学,2012,37(1):191-198. |
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| 作者姓名： | 薛艳 刘杰 尹继尧 宋治平 |
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| 作者单位： | 1.中国地震局地球物理研究所, 北京 100081 |
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| 基金项目： | 国家"973"项目2008CB425704 |
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| 摘 要： | 分析了全球、环太平洋地震带(P系)和低纬度环球剪切带(E系)的地震活动特征, 并运用小波变换技术对地震活动周期成分进行了定量研究, 结果表明: (1)全球地震活动存在45.5 a和32.0 a的显著周期成分, P系为45.5 a, E系为30.9 a和47.5 a; (2)全球及两大构造系7.0级以上地震频度均显示30.0 a左右的周期特征, 但地震频度与全球8.5级以上特大地震活动是不同步的, 不能作为判定地震活跃期与平静期的依据, 频度变化可能反映全球尺度的某种活动对地震产生的影响; (3)全球地震具有50.0 a尺度的活跃期与平静期; 当前全球地震活动处于2004年开始的以8.5级以上地震活动为特点的大释放阶段, 这种状态还将持续数年; E系处于Mw≥7.8大震活跃期的尾声, 而2010年智利Mw=8.8地震可能标志着P系开始进入大释放阶段.
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| 关 键 词： | 地震 地震活动周期 环太平洋地震带 低纬度环球剪切带 小波分析 地震波 |
| 收稿时间： | 2010-11-08 |
Characteristics of Global Great Earthquakes |
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| Abstract: | Using the global earthquake catalogue with Mw≥7.0 since 1900, we analyze the characteristics of great earthquakes in the global area, the circum-Pacific seismic belt (namely P-system)and the low-latitude circum-earth zone (namely E-systerm) respectively. In addition, the technique of Morlet wavelet transform is applied to quantitatively analyze the seismicity periodicities. Results show: (1) there are two principal periodic components, including 45.5 a and 32.0 a, in the global seismicity. For the P-system, the principal period is 45.5 a. The principal periodic components are 30.9 a and 47.5 a in the seismicity of the E-system; (2) The earthquake frequency with Mw≥7.0 of the globe, the P-system and the E-system show a prominent period of about 30 a. However, the temporal process of earthquake frequency is not synchronous with the global seismicity of Mw≥8.5, so it is not properly distinguish the active or quiet period by frequency and the variation of earthquake frequency may be a reaction that some global activity influence on the global seismicity; (3) The global great earthquakes showing the seismicity period is about 50.0 a (including an active and a quiet period). Great earthquakes (Mw≥8.5) in globe occurred frequently since 2004, showing a high actively trend based on the characteristics of great earthquakes cyclic process. It has been in high active period with many large earthquakes(Mw≥7.8) in the E-system since 1992, and currently it is in the end of the active period. The 2010 Chile Mw=8.8 event may be the sign that it begins a new active period in the P-system. |
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