论文部分内容阅读
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45.5a和32.0a的显著周期成分,P系为45.5a,E系为30.9a和47.5a;(2)全球及两大构造系7.0级以上地震频度均显示30.0a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50.0a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.
The earthquakes in the world, the Pacific Rim (P series) and the low latitudes (E series) are analyzed. The wavelet analysis is used to quantitatively study the seismic activity components. The results show that: (1) There are 45.5a and 32.0a significant periodic components in seismicity, with P series of 45.5a and E series of 30.9a and 47.5a; (2) earthquakes of magnitude 7.0 and above in both the global and the two tectonic systems show a period of about 30.0a However, the frequency of earthquakes is asynchronous with the extraordinary earthquakes above 8.5 magnitude in the world and can not be used as the basis for judging the active and quiet periods of the earthquakes. The frequency change may reflect the impact of certain activities on the global scale on earthquakes. ) Global earthquakes have a 50.0a scale active period and quiet period; the current global seismicity is at a large release stage characterized by earthquakes above M 8.5 in 2004, and this state will continue for several years; E system is in the range of Mw≥ 7.8 earthquake active period of the end, and 2010 Mw = 8.8 earthquake in Chile may mark the beginning of the P system into a large release phase.