三次8级以上大地震的余震活动特征分析  

Analysis on Characteristic of Aftershock Activity of the Three M≥8.0 Huge Earthquakes

作　　者：史海霞[1] 孟令媛[1] 刘杰[1] 李智超[1] 

机构地区：[1]中国地震台网中心,北京100045

出　　处：《地震研究》2015年第4期549-557,697,共9页Journal of Seismological Research

基　　金：地震局地震行业专项(20150810);国家自然科学基金项目(41404045);地震局震情跟踪项目(2015010121);台网中心青年基金(QNJJSQ-YBB-1404)联合资助

摘　　要：统计研究了2004年12月26日印尼苏门答腊MW9．0、2008年5月12日中国汶川Ms8．0和2010年2月27日智利Mw8．8三次大震后一个月内（特别关注24h，15d，30d3个时段）余震序列的时空强演化特征。结果显示，大震序列的时间和强度具有显著的分时段起伏特征，而余震频次呈现阶梯式衰减。大震后第1—2天内和第13—17天余震强度最大，有可能发生最大余震，最大余震位于余震区端部的可能性较大，且利用震后3h的余震可估计余震区范围。最后，讨论了强余震起伏时段以及最大强余震可能与固体潮调制具有相关性。In order to explore seismic activity features after the huge earthquake shortly, we statisticed the evolution characteristics of the spatial, temporal and intensity distribution in one month （focus on 24 hours, 15 days and one month respectively） after three huge earthquakes. The three huge earthquakes are Sumatra Mw9.0 earth-quake in Indonesia on Dec. 26, 2004, Wenchuan Ms8.0 earthquake in China on May. 12, 2008 and Chile Mw8.8 earthquake on Feb. 27, 2010. The results show that the characteristics of time and intensity distribution of the earthquake sequence had obvious ups and downs during the different time periods, and the frequency of aftershocks showed the stepped attenuation. Furthermore the aftershock activity was the strongest in the 1 ~ 2 days and 13 - 17 days after the huge earthquake. The maximum aftershock was probably to occur in the end of aftershock zone, and we could use the aftershocks in 3 hours after main shock to estimate the scale of aftershock zone. In addition, we also discussed that the period of the ups and downs characteristic of strong aftershock ac- tivity, and their relationship with the tidal modulation period.

关 键 词：余震序列特征 最大余震 强余震迁移 平静时间间隔 固体潮调制 

分 类 号：P315.72[天文地球—地震学]