摘要
利用2013~2017年3期GPS观测资料,通过结合区域构造背景分析呼图壁MS6.2地震震中及附近区域水平运动速率、主应变率、面膨胀率及最大剪应变率动态变化特征。结果表明,呼图壁地震前发震构造南部区域地壳速率高于北部区域运动速率,造成发震构造两盘运动速率不同,地壳能量积蓄。呼图壁地震释放了区域积蓄的应变能量,由于区域构造因素,影响范围较小。震前震中附近区域处于压缩环境,易于聚集应变能量;震时震中区出现面膨胀等值线密集高梯度带,是地壳应变能量交换和释放剧烈区域。震中区最大剪应变变化不大,反映呼图壁地震逆冲性质,最大剪应变高值区对地震危险性有预示作用。
Based on the GPS observation data from 2013 to 2017,the dynamic changes of horizontal movement rate,principal strain rate,surface expansion rate and maximum shear strain rate in the epicenter and adjacent area of Hutubi MS6.2 earthquake are analyzed by combining with regional tectonic background.The results show that the crustal velocity in the southern region of the seismogenic structure is higher than that in the northern region before the Hutubi earthquake,resulting in the different velocity of the two plates of the seismogenic structure and the accumulation of crustal energy.The Hutubi earthquake releases the strain energy accumulated in the region,but the influence range is small because of the regional tectonic factors.Before the earthquake,the region near the epicenter is in a compressive environment,which is easy to accumulate strain energy.During the earthquake,a high gradient zone with dense surface expansion isoline appears in the epicenter area,which is a region where the crustal strain energy exchange and release are intense.The maximum shear strain in the epicentral region has little change,which reflects the thrust property of Hutubi earthquake.The high value area of the maximum shear strain can predict the seismic risk.
作者
朱治国
秦姗兰
李杰
刘代芹
李桂荣
方伟
杨磊
ZHU Zhi-guo;QIN Shan-lan;LI jie;LIU Dai-qin;LI Gui-rong;FANG wei;YANG Lei(Earthquake Agency of Xinjiang Uygur Autonomous Region,Urumqi 830011,Xinjiang,China;Second Crust Monitoring and Application Center of CEA,Xi’an 710054,Shaanxi,China)
出处
《内陆地震》
2019年第2期97-104,共8页
Inland Earthquake
基金
中国地震局地震科技星火计划项目(XH17044)
地震科技星火计划项目XH18054
新疆维吾尔自治区区域协同创新专项2017E01030
国家自然科学基金41574012
