雷琼地区重力场动态变化特征研究  

Study on the Dynamic Characteristics of Gravity Field in Leiqiong Area

作　　者：李盛[1] 廖桂金[2] LI Sheng;LIAO Guijin(Hainan Earthquake Agency,49 Meiyuan Road,Haikou 570203,China;Guangdong Earthquake Agency,81 Mid-Xianlie Road,Guangzhou 510070,China)

机构地区：[1]海南省地震局,海口市570203 [2]广东省地震局,广州市510070

出　　处：《大地测量与地球动力学》2020年第11期1118-1125,共8页Journal of Geodesy and Geodynamics

基　　金：中国地震局地震科技星火计划(XH21024Y);中国地震局震情跟踪定向工作任务(2019010202,2020010213);中国地震局“三结合”课题(3JH-201901038)。

摘　　要：基于2016年以来雷州半岛-海南岛陆地区(以下简称雷琼地区)的流动重力资料,对2017年下半年前后的联测资料采用不同的平差方法进行处理。将湛江和琼中2个绝对重力点作为雷琼测网基准,研究2016年以来雷琼地区重力场动态变化特征。重点研究2018-03-20广东阳江4.2级地震、2019-03-05广东雷州4.1级地震、2019-08-20海南三亚4.2级地震和2019-10-12广西北流5.2级地震震前区域重力场差分和累积动态变化。研究结果表明,除广东雷州4.1级地震外,其他3个地震震前在震中附近地区均存在重力场变化异常,表明在测网网格距和数据处理方法合理的情况下,对于4~5级地震,区域重力场在震前可能存在一定异常反应。Based on mobile gravity observation data from Leiqiong area since 2016,we process the joint observation data in the second half of 2017 by using different adjustment methods.The Zhanjiang and Qiongzhong absolute gravity points are considered as the spatial reference of the Leiqiong survey network,and we study the dynamic changes of gravity field in Leiqiong area since 2016.We focus on the differential and cumulative dynamic changes of regional gravity fields before the 2018-03-20 Yangjiang M4.2,the 2019-03-05 Leizhou M4.1,the 2019-08-20 Sanya M4.2,and the 2019-10-12 Beiliu M5.2 earthquakes.The results show that there are abnormal changes in the gravity field near the epicenter before the earthquakes,except the Leizhou M4.1 earthquake.The results of this study indicate that the regional gravity field may reflect a certain preseismic anomalous of magnitude 4~5 earthquakes with reasonably dense observation networks and proper data processing methods.

关 键 词：流动重力 空间基准 重力场变化 地震 

分 类 号：P312[天文地球—固体地球物理学]