摘要
2004年12月15日起,四川省马尔康县出现一个地震序列,最大事件为2005年1月5日MS4.7地震。本文介绍了利用单台P波初动以及振幅比方法对该序列发展跟踪和判断的情况。结果表明,序列前期事件的震源机制具有一致性,序列的主要事件均发生在此时间段;序列后期机制出现紊乱。该方法可为序列性质的判断提供依据。通过比较,认为速度量振幅比的变化基本反映了位移零频观测谱值的振幅比的变化。
An earthquake sequence occurred in Maerkang county, Sichuan Province since Dec. 15,2005, and the main shock is Ms 4.7 on Jan. 5, 2005. The process of judgment to this sequence＇s development using single station P - wave first motion and amplitude- ratio method had been described. The results show that in earlier period of sequence the events with consistency of focal mechanisms, and the major events occurred within this period. But in the later period the focal mechanisms of events become chaos. This method can be used to identify the sequence characteristics. We have also proposed that velocity amplitude- ratio can represent observed low- frequency spectral amplitude- ratio by comparison.
出处
《地震地磁观测与研究》
2005年第4期29-35,共7页
Seismological and Geomagnetic Observation and Research
基金
"十五"科技攻关项目(2004BA601B01-04-03数字化资料在地震序列中的应用研究)资助
关键词
马尔康Ms4.7地震
震源机制
振幅比
零频谱值
Maerkang Ms 4.7 earthquake, focal mechanism, amplitude- ratio, low-frequency amplitude
