郯庐断裂带中南段重力场变化与重力异常关系的探讨  

Exploration of the Relationship between the Gravity Field Changes and the Gravity Anomalies in the Middle-southern Section of the Tancheng-Lujiang Fault Zone

作　　者：孙鸿博[1,2] 梁霄 王季雨[1,2] 肖伟鹏 陆元超 孙伯乐[1,2] 严吉 周志 徐如刚 储飞 SUN Hongbo;LIANG Xiao;WANG Jiyu;XIAO Weipeng;LU Yuanchao;SUN Bole;YAN JI;ZHOU Zhi;XU Rugang;CHU Fei(Anhui Earthquake Agency,Hefei 230031,Anhui,China;Anhui Key Laboratory of Subsurface Exploration and Earthquake Hazard Risk Prevention(in prep.),Hefei 230031,Anhui,China)

机构地区：[1]安徽省地震局,安徽合肥230031 [2]安徽省地下结构探测与震灾风险防范重点实验室(筹),安徽合肥230031

出　　处：《地震研究》2025年第4期584-593,共10页Journal of Seismological Research

基　　金：安徽省地下结构探测与震灾风险防范重点实验室(筹)开放基金(KLB-2025KFQN-004).

摘　　要：使用经典平差和贝叶斯平差法对2013年上下半年、2020年上下半年以及2024年郯庐断裂带中南段的重力数据进行平差处理,获得了2013—2024年研究区的重力场变化。结果显示,该研究区的重力场呈现东升西降的变化趋势,郯庐断裂带对重力变化控制明显。结合对重力场变化的小波分解结果和2013—2022年研究区发生的M S≥3.5地震,发现地震易发生在重力场变化的正负交界过渡带上。采用EGM2008模型,经小波多尺度分解,获得去除了莫霍面起伏影响的布格重力异常,根据Airy均衡模型计算得到均衡重力异常。结果表明,总体上重力场的变化与重力异常在空间形态上较为一致,但变化趋势可能有所不同,需重点关注重力异常的边界与重力场变化的边界一致的地方,有发生地震的可能性。We select the gravity data measured in the middle and southern section of the Tancheng-Lujiang Fault Zone in the year 2013,2020,and 2024 for adjustment processing,and obtain the gravity variation in the study from 2013 to 2024.The results show that the gravity field variation has a trend of rising in the east part and falling in the west part of the study area,and the Tancheng-Lujiang Fault Zone significantly controls the gravity variation.Further,we decompose the gravity field variation with wavelet analysis.Referring to the recent earthquake cases(M≥4.0)in the study area,we find that these earthquakes are prone to occuring in the transitional zones between the positive variation and the negative variation of the gravity field.We use the EGM2008 model to do the wavelet multiscale decomposition,and obtain the Bouguer gravity anomaly without the influence of the Moho surface undulation.Finally,we calculate the isostatic gravity anomaly by the Airy equilibrium model.We find that the gravity field variation is generally consistent with the shape of gravity anomalies.The positive and negative areas of the gravity field may be opposite to the areas of the isostatic gravity anomalies,but the spatial range of abnormal variation of the gravity field is consistent with the spatial range of the isostatic gravity anomalies.As the earthquake prone areas,these spatial ranges need to be paid more attention to.

关 键 词：重力场变化 贝叶斯平差 郯庐断裂带 布格重力异常 小波分解 

分 类 号：P312.11[天文地球—固体地球物理学]