青藏高原东南缘多尺度重力场及构造含义  

Multi-Scale Gravity Field of Southeastern Tibetan Plateau and its Tectonic Significance

作　　者：陈兆辉[1] 陈石[2] 张双喜[1] 刘金钊[1] CHEN Zhao-hui;CHEN Shi;ZHANG Shuang-xi;LIU Jin-zhao(The First Monitoring and Application Center,China Earthquake administration,Tianjin 300180,China;Institute of Geophysics,China Earthquake administration,Beijing 100081,China)

机构地区：[1]中国地震局第一监测中心,天津300180 [2]中国地震局地球物理研究所,北京100081

出　　处：《地震》2021年第1期25-39,共15页Earthquake

基　　金：地震科技星火计划(XH20078Y、XH19064Y);中国地震局震情跟踪课题(2016010203、2018010209);中国地震局“监测、预报、科研”三结合课题(CEA-JC/3JH-173701)联合资助。

摘　　要：本文基于EGM2008重力场模型研究了青藏高原东南缘均衡重力异常和多尺度的布格重力异常特征,以鲁甸和景谷地震为例,认识其深部构造环境和动力学过程,为该区域的构造运动和地震孕育环境研究提供依据。结果表明,研究区布格重力异常和均衡重力异常与地质构造格局相关性较好,川滇地块剧烈的区域布格重力异常和非均衡状态与其强烈的地壳变形、断裂及地震活动密切相关。强震多分布在断裂带两侧重力异常的过渡地带和高梯度带,断裂带两侧横向和垂向的显著介质密度差异是强震孕育的深部构造背景。布格重力异常和均衡重力异常揭示的鲁甸、景谷震源区深浅差异性的重力异常特征,暗示鲁甸和景谷地震孕震环境的不同。On August 3 and October 7,2014,the Ludian M_(S)6.5 earthquake and Jinggu M_(S)6.6 earthquakes respectively occurred in Yunnan,China.Based on the EGM2008 gravity field model,this paper studies the Isostatic gravity anomaly and multi-scale Bouguer gravity anomaly of the southeastern Tibetan Plateau.The deep tectonic environment and dynamic process of the Ludian and Jinggu earthquakes are analyzed and recognized,which provide a deep understanding of tectonic movement and earthquake inoculation environment in this region.The Bouguer gravity anomaly and the Isostatic gravity anomaly in the study area are correlated well with the geological structure,and the severe regional Bouguer gravity anomalies and the non-equilibrium state of the Sichuan-Yunnan block are closely related to its strong crustal deformation,fracture and seismic activity.The strong earthquakes in the study area are mainly distributed in the transition zone and high gradient zone of gravity anomaly on both sides of the fault zone,and the significant difference of medium density on both sides of the fault zone is the deep tectonic background of strong earthquakes.The difference of the deep and shallow density structure of Ludian and Jinggu hypocentral region being revealed by Bouguer gravity anomaly and Isostatic gravity anomaly indicates,the seismogenic environment difference between Ludian and Jinggu earthquakes.

关 键 词：重力场 小波多尺度分析 青藏高原东南缘 EGM200 鲁甸地震 景谷地震 

分 类 号：P315.7[天文地球—地震学]