利用黏弹性球体位错理论研究2004年苏门答腊地震震后效应对华南块体的影响

扫码查看

原文链接

万方数据
维普

中文摘要：本文基于黏弹性球体位错理论和GNSS观测资料,约束东南亚地区大范围地幔黏滞性结构,探讨该地震的震后形变及其对华南块体的影响.首先收集泰国地区震后位移资料,考虑兼顾稳态和瞬态震后形变的Burgers黏弹性体,利用黏弹性球体位错理论进行模拟,得到软流圈麦克斯韦黏滞性系数(ηm)为5×1018Pa·s,开尔文体黏滞性系数与麦克斯韦体比值(a)为0.3,开尔文体剪切模量与麦克斯韦体比值(γ)为0.33.进而收集和模拟华南块体及其周边区域震后形变,GNSS流动站观测资料显示震后2年形变主要集中于华南块体南部,观测与模拟震后位移方向整体一致,往西南方向指向震中,震后形变量上存在明显差异,云南地区模拟值偏大,而华南块体南部模拟值偏小.GNSS连续站观测资料显示,华南块体受苏门答腊地震震后形变的影响在2010年后明显减弱.后续地壳变形研究以华南块体为参考基准时,建议基于2016年以后的观测提取速度场.

外文标题：A study of post-seismic effect of the 2004 Sumatra earthquake on the South China Block based on the viscoelastic spherical dislocation theory

外文摘要：Based on the viscoelastic spherical dislocation theory and GNSS observation data,this paper constrains the large-scale mantle viscosity structure in Southeast Asia,and explores the post-seismic deformation after the 2004 Sumatra earthquake and its effect on the South China block.First of all,this paper collected the post-seismic displacement data in Thailand,and considering the Burgers viscoelastic body with steady state and transient deformation characteristics,performed simulations based on the viscoelastic spherical dislocation theory.The results shows that the Maxwell viscosity coefficient(ηm)of asthenosphere is 5×1018Pa·s,the ratio of the Kelvin body viscosity coefficient to the Maxwell body viscosity(a)is 0.3,and the ratio of the Kelvin body shear modulus to the Maxwell body shear modulus(γ)is 0.33.Further,this paper collected and simulated the post-seismic deformation data of the South China Block and its surrounding areas.Campaign GNSS observation data indicate that the post-seismic deformation in 2 years after the earthquake mainly occurred in the southern South China Block.The observed and simulated post-seismic displacement directions are generally consistent,pointing from the southwest to the epicenter.There is a significant difference in the magnitude of post-seismic deformation.The simulated value in Yunnan is relatively large,while that in the southern South China Block is relatively small.Continuous GNSS observation data indicate that the effect of the post-seismic deformation after the 2004 Sumatra earthquake on the South China block has been weakened significantly since 2010.The crustal deformation will be further studied based on the data of the South China Block,it is suggested that the velocity field should be extracted according to the observations after 2016.

外文关键词：

2004 Sumatra earthquakeViscoelastic bodySouth China BlockGNSS observation data

作者：

刘泰、邹镇宇、吴伟伟、佘雅文、付广裕、孟国杰

展开 >

作者单位：

中国地震局地震预测研究所,北京 100036

中国地质大学(北京)地球物理与信息技术学院,北京 100083

关键词：

2004年苏门答腊地震黏弹性体华南块体 GNSS观测资料

基金：

国家自然科学基金国家自然科学基金中国地震局地震预测研究所基本科研业务费专项中国地震局地震预测研究所基本科研业务费专项中国地震局地震预测研究所基本科研业务费专项

项目编号：

4210408642274008CEAIEF20240208CEAIEF2024030103CEAIEF2024030104

出版年：

2024

DOI：

10.6038/cjg2024R0575

地球物理学报

中国地球物理学会中国科学院地质与地球物理研究所

地球物理学报

CSTPCD北大核心

影响因子：3.703

ISSN：0001-5733

年,卷(期)：2024.67(9)