2021年漾濞M_(S)6.4地震前重力段差指标量分析及场源特征反演  

Analysis of the Gravity Variation Index before the Yangbi M_(S)6.4 Earthquake and Inversion of the Field Source Characteristics

作　　者：郑秋月 黄江培 吴宇琴 陈政宇 刘东 王青华[1] ZHENG Qiuyue;HUANG Jiangpei;WU Yuqin;CHEN Zhengyu;LIU Dong;WANG Qinghua(Yunnan Earthquake Agency,Kunming 650224,Yunnan,China)

机构地区：[1]云南省地震局,云南昆明650224

出　　处：《地震研究》2025年第1期22-31,共10页Journal of Seismological Research

基　　金：中国地震局震情跟踪项目(2024010201);云南省地震局创新团队(CXTD202410);云南省地震局科技专项(2024X03、2024X04);地震科技星火计划(XH24027YC).

摘　　要：基于2016-2021年云南地区流动重力重复观测资料,利用流动重力段差变化可视化方法及重力场变化显著性程度指标量G和C值研究了2021年漾濞M_(S)6.4地震前的重力变化,并反演了其与地震孕育相关的场源分布特征,开展了对研究区重力变化及场源特征的定性和定量研究。结果表明:①段差表示法的大小和方向对地下物质的运移方向有一定的指示意义,震前重力指标量呈显著上升,震后又迅速回落,重力变化指标量G和C值可作为评价测网区域重力变化显著性程度的定量依据;②反演得到的重力变化场源位置主要集中在红河断裂带北段至滇西北一带,且表现出与维西-乔后断裂及红河断裂带走向较为一致的分布特征,这可能与地震前中上地壳的深部物质运移相关。In this paper,we use the visualization method of the gravity segment differences and the quantitative indicators of gravity variation G and C,to process the mobile gravity data obtained by repeated measurements in Yunnan from 2016 to 2021 and study the gravity variation before the Yangbi M_(S)6.4 earthquake on May 21,2021.We further invert the distribution characteristics of seismic-related source in the study area.The results are as follows:①The scale and the direction of the gravity segment indicated more or less the migration direction of the subsurface material,and the gravity variation indicators G and C increased significantly before the Yangbi earthquake,then decreased rapidly after the earthquake.G and C can be used to evaluate the significance of the regional gravity changes in the area covered by the gravity observation network.②The inverted positions of the field-source mainly concentrated in the zone from the northern section of the Red River Fault Zone to the northwestern Yunnan,exhibiting a distribution pattern consistent with the Weixi-Qiaohou Fault and the Red River Fault Zone;this situation was possibly correlated with the migration of the deep material in the middle and upper Crust before the Yangbi earthquake.

关 键 词：重力段差 定量分析 重力变化指数 场源反演 漾濞M_(S)6.4地震 

分 类 号：P315.726[天文地球—地震学]