• 责任者：Jiang Changsheng (Institute of Geophysics ; China Earthquake Administration ; Beijing 100081 ; China) ; Wu Zhongliang
• 刊名：Chinese Journal of Geophysics
• 出版年：2013
• 卷期：56(12)
• 关键词：地震预测 ; earthquake prediction ; 甘肃 ; Gansu Province
• 页码：p.4048-4057
• 图表：7 illus., 1 table, 42 refs.
• 分类号：0500
• issnNo：ISSN0001-5733
• isbnNo：CN11-2074/P

     The effect of cutoff magnitude Mc of an earthquake catalogue on the result of the analysis of earthquake sequence was investigated using the epidemic type aftershock sequence （ETAS） model to the 2013 Minxian Zhangxian, Gansu, China, Ms6. 6 earthquake sequence. Considering the early stage of aftershock sequence within about 1. 6 days after the mainshock, ETAS model and modified Omori-Utsu relation were used to estimate the earthquake sequence parameters. The AICs of ETAS model are smaller than the modified Omori-Utsu relation for all the considered cutoff magnitude M~., implying that the sequence was better fitted by the ETAS model. Setting different Mc from M~.I. 0 to 2.5 with interval 0.1, the stability of parameter ~ and p was investigated, with the comparison with the 2013 Lushan, Sichuan, Ms7.0 earthquakesequence. The result shows the effect of Mc on the estimation of these parameters, with p more sensitivite to Me. N-test was performed to the probabilistic forecast of aftershocks based on ETAS model and ＂thinning algorithm＂, indicating the effect of Mc on the forecast performance for the Minxian-Zhangxian sequence. Acceptable result was obtained only with Mc-ML 1.0 or Ml.1.1. The analysis cautions that in the practical forward forecas~ of aftershock probabilities, cutoff magnitude is a key factor to be considered.