2020年伽师M_(S)6.4地震前后重力变化  

Gravity Changes before and after the 2020 Jiashi M_(S)6.4 Earthquake

作　　者：杨雄 祝意青[1] 赵云峰[1] 隗寿春 操聪 吕宏斌 曾亚光 YANG Xiong;ZHU Yiqing;ZHAO Yunfeng;WEI Shouchun;CAO Cong;L Hongbin;ZENG Yaguang(The Second Monitoring and Application Center,CEA,316 Xiying Road,Xi’an 710054,China)

机构地区：[1]中国地震局第二监测中心,西安市710054

出　　处：《大地测量与地球动力学》2024年第3期277-282,共6页Journal of Geodesy and Geodynamics

基　　金：国家自然科学基金(U1939205,41874092)。

摘　　要：基于2016年以来南疆相对重力和绝对重力观测资料,系统分析南疆区域重力场动态变化及其与2020-01-19伽师M_(S)6.4地震的关系。结果表明:1)区域重力场变化与区域构造关系密切,沿柯坪断裂形成多个局部重力异常区及重力变化高梯度带,反映出2016~2020年该断裂活动引起显著的地表重力场变化;2)与伽师地震孕育有关的重力场经历了“重力正异常区-四象限特征及沿柯坪断裂的重力高梯度带-反向变化发震”的演化过程;3)重力场累积变化和差分变化图像均反映出伽师地震前出现显著的重力异常变化,地震发生在重力变化梯度带、四象限中心和零等值线拐弯附近;4)重力场动态演化较好地反映出伽师M_(S)6.4地震孕育发生过程中出现的中期前兆现象,基于流动重力异常变化在伽师M_(S)6.4地震前进行一定程度的中期预测,尤其是强震地点判定。Based on the observation data of relative gravity and absolute gravity in southern Xinjiang since 2016,the dynamic change of regional gravity field in southern Xinjiang region and its relationship with the Jiashi M_(S)6.4 earthquake on January 19,2020 are systematically analyzed.The results show that:1)The change of regional gravity field is closely related to regional tectonics,and many local gravity anomaly areas and high-gradient zones of gravity change are formed along Keping fault,implying that the fault activity caused significant changes of surface gravity field during 2016 to 2020.2)The gravity field related to the preparation of the Jiashi earthquake has experienced evolution process of“positive gravity anomaly area—four quadrants distribution characteristic and high-gradient zone of gravity change along Keping fault—reverse change and earthquake occurrence”.3)The cumulative change and differential change of gravity field all reflect the significant gravity anomaly changes before the Jiashi earthquake,which occurred in gradient zone of gravity change,the center of four quadrants,and near the turning of zero contour line.4)The dynamic evolution of gravity field well reflects the medium-term precursor phenomenon during the preparation and occurrence of the Jiashi M_(S)6.4 earthquake.Based on the anomaly changes of mobile gravity,a certain degree of medium-term prediction was made before the Jiashi M_(S)6.4 earthquake,especially the location determination of strong earthquakes.

关 键 词：新疆地区 伽师地震 重力观测 重力变化 

分 类 号：P312[天文地球—固体地球物理学]