Comparison of the 1999 Chi-Chi Mw 7.6 Earthquake and the 2008 Wenchuan MS 8.0 Earthquake
p value in Omori’s law and the b value in G-R relation are probably the most broadly accepted statistics in seismicity study. In this paper, we focused on the p and b values of two great earthquake sequences occurred in China, the 1999 Chi-Chi Mw7.6 earthquake and the 2008Wenchuan Ms8.0 earthquake. We calculated both values of each sequence, analyzed some statistic characters of these values, compared them, and drafted some features based on the calculation and comparison. By comparing the temporal variation of bvalue with the moment cumulating, we found that almost each inflexion on the cumulative moment curve corresponded to a sharp hop on the temporal fluctuation of b value. This might due to the fact that b value indicates stress condition in the same region. Earthquake releases strain energy, causing stress to change. As a result, the temporal undulation of b value may indicate the variation of stress condition. Furthermore, we attempted to explain the different aftershock distribution pattern of the two earthquakes. The primary determinants, referring to geological data, may be the trend and pattern of the fault system and stress state in the aftershock district.
Y. Liu S.B. Zhu
Institute of Crustal Dynamics, CEA
国际会议
The Fifth International Symposium on In-situ Rock Stress(第五届国际岩石应力研讨会)
北京
英文
659-664
2010-08-25（万方平台首次上网日期，不代表论文的发表时间）