祁连—海原断裂带强震库仑应力演化特征研究

发布时间：2017-12-31 19:14

本文关键词：祁连—海原断裂带强震库仑应力演化特征研究　出处：《地震研究》2016年04期 　论文类型：期刊论文

【摘要】：研究祁连—海原断裂带及其附近区域自1920年海原M_S8.5地震后至今发生的6次M_S≥7.0强震间的相互触发关系,基于Burgers体构建粘弹性介质模型,模拟同震和震后库仑应力的演化过程;进一步针对祁连山北缘断裂带、西秦岭北缘断裂带及六盘山断裂带3条主要断裂带,分别计算自1920年至今6次强震在这3条断裂带上近百年尺度的应力累积。结果表明:1927年古浪M_S8.0地震受到1920年海原M_S8.5地震同震和震后库仑应力的共同加载,1954年民勤M_S7.0地震和1990年共和M_S7.0地震均受到之前发生强震的库仑应力的累积加载影响;西秦岭北缘断裂位于6次强震震后的综合累积应力卸载区,六盘山断裂带则位于累积应力加载区。研究强震间库仑应力演化特征及其对周围断裂带的较长时间尺度的累积影响,需要合理考虑粘弹性松弛效应下的震后库仑应力的累积作用,也可结合地震活动性进一步为明确危险断层段提供合理的参考。
[Abstract]:Mutual relations since the 1920 Haiyuan earthquake triggered after M_S8.5 has occurred and the surrounding region of Qilian Haiyuan fault zone 6 M_S = 7 earthquake of Burgers construction of viscoelastic medium model based on Evolution Simulation of coseismic and postseismic Coulomb stress; further in view of Qilian Mountains and the northern margin fault zone, with 3 major faults in west the northern margin of the Qinling Mountains fault zone and six mountain fault zone were calculated since 1920 6 strong earthquakes in the 3 fault zone near the Centennial scale of stress accumulation. The results show that the 1927 Gulang M_S8.0 earthquake by loading M_S8.5 1920 Haiyuan earthquake coseismic Coulomb stress and earthquake, M_S7.0 earthquake in 1990 and 1954 in the Republic M_S7.0 is the loading effect of seismic cumulative Coulomb stress before earthquake; 6 earthquake after the earthquake in West Qinling Mountains is located in the northern margin fault comprehensive cumulative stress unloading region, six Mountain Fault Zone In the cumulative stress loading area. Research on seismic Coulomb stress accumulation between evolution and long time around the fault zone scale, need reasonable consideration of the cumulative effect of postseismic viscoelastic relaxation under the effect of Coulomb stress, can also be combined with seismic activity further clear dangerous fault segments provide a reasonable reference.

【作者单位】：中国地震台网中心;中国地震局地质研究所地震动力学国家重点实验室;
【基金】：中国地震局地震行业科研专项(201508010)、中国地震局监测预报司震情跟踪定向工作任务(2015010103)联合资助国家自然科学基金(41404045;41304073) 地震科技星火计划(XH15011)
【分类号】：P315.727
【正文快照】： 0引言青藏高原是我国现代最新构造活动与地震活动最强烈的地区,其南部为印度板块与欧亚板块俯冲碰撞形成的喜马拉雅现代造山带,沿该带曾发生过多次8级以上的巨大地震。喜马拉雅现代构造活动带以北的印度板块经强烈碰撞形成的广阔高原地区,影响范围宽度最长可达1 600 km,直达祁

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