2014年康定M_s6.3级地震发震断裂的古地震  

The Holocene paleoearthquakes on the 2014 Kangding M_s6.3 earthquake faults

作　　者：胡朝忠[1] 杨攀新[1] 梁朋[1] 苏鹏[1] 熊仁伟[1] 李小强[1] 陈丹[1] 李长军[2] 

机构地区：[1]中国地震局地震预测研究所地震预测重点实验室,北京100036 [2]中国地震局第二监测中心,西安710054

出　　处：《科学通报》2015年第23期2236-2244,共9页Chinese Science Bulletin

基　　金：国家自然科学基金(41302171;41272233);中国地震活断层探查-南北带中南段(60112304);中国地震局基本科研业务经费(2014IES0401;2012IES010303)资助

摘　　要：2014年11月22日四川康定发生Ms6.3级地震,综合震源机制解、余震分布、区域断裂展布及震前对区域断裂的野外详细调查研究,发现本次地震的发震断裂是鲜水河断裂带色拉哈段.但对色拉哈段的古地震背景还缺乏深入了解,依据遥感解译、野外考察、4个探槽的开挖、测年样品采集测试等古地震研究技术,综合研究表明：（1）鲜水河断裂带色拉哈段全新世以来发生过多次地表破裂型古地震事件,色拉哈段上最新一次地表破裂型古地震事件的发生时间为2027~2359 a BP,在本段上发生康定Ms6.3级地震或更强烈的地震事件丝毫不让人意外;（2）色拉哈段上全新世以来的古地震事件表现出明显的丛集期和平静期相间的特征,在6812~11316 a BP之间表现出明显的丛集特征,复发周期1000 a左右,而在6812 a BP以来仅在3840~4295和2027~2359 a BP之间发生两次古地震事件,复发间隔明显变长.On November 22, 2014, a Ms6.3 earthquake occurred in Kangding, Sichuan Province. After the field survey of fracture in this region, the Selaha segment of Xianshuihe fault zone is confirmed as the earthquake fault based on comprehensive research of focal mechanism, distribution of the aftershock and regional faults. In this paper, the author revealed the characters of Holocene paleoearthquakes of this segment through interpretation of remote sensing, field investigation, four trenches excavating, sample dating and other research techniques, concluded as： （1） There are many paleoearthquakes happened in this segment. The elapsed time from the latest one is up to 2027-2359 a BP, so it should be no surprise that the earthquake or even more stronger earthquake occurred in this segment. （2） The paleoearthquakes in the Holocene showed obvious periodicity in Selaha segment. It shows obviously clustering characteristics between 6812-11316 a BP, recurrence intervals may around 1000 years. Since 6812 a BP, there has been only two earthquakes which were between 3840-4295 a BP and 2027-2359 a BP, and the time of recurrence interval was significantly longer.

关 键 词：康定地震 发震断裂 鲜水河断裂带 色拉哈段 古地震 离逝时间 复发间隔 

分 类 号：P315.3[天文地球—地震学]