2014年云南鲁甸6.5级地震序列参数的早期特征*

(中国地震局地球物理研究所,北京 100081)

地震序列; ETAS模型; 截止震级; 云南鲁甸MS6.5地震

Parameter Characteristic in the Early Stage of Yunnan Ludian MS6.5 Earthquake Sequence in 2014
GUO Lu-jie,JIANG Chang-sheng,HAN Li-bo

(Institute of Geophysics,CEA,Beijing 100081,China)

earthquake sequence; ETAS model; cutoff magnitude; Yunnan Ludian MS6.5 earthquake

备注

利用“传染型余震序列”(ETAS)模型,考虑不同的截止震级和序列持续时间的影响,对2014年鲁甸6.5级地震后9 d内的序列参数特征进行了研究。结果 表明,当选取截止震级MC=ML2.0时,可获得相对稳定可靠的p值和α值等序列参数,其中p=0.89~1.10,显示了较慢的衰减特征,α值在震后5.0 d出现大幅下降,表明激发次级余震的能力出现显著变化。

Based on the epidemic-type aftershock sequence(ETAS)model,considering the influence of different cutoff magnitude and duration time,we investigated the parameter characteristics in the early stage of Yunnan Ludian MS6.5 earthquake sequence in 2014. It is observed that the p and α values kept stable and reliable when the cutoff magnitude MC=ML2.0 was selected. The result of p=0.89~1.10 indicated that it had a slow decay rate of aftershocks. The α-value showed a sharp drop on the 5th day after the main shock,which indicated the ability of provoking aftershocks change greatly.