Determination of the degree 120 time-variable gravity field in the Sichuan-Yunnan region using Slepian functions and terrestrial measurements  

作　　者：Jiancheng Han Shi Chen Zhaohui Chen Hongyan Lu Weimin Xu 

机构地区：[1]Institute of Geophysics,China Earthquake Administration,Beijing 100081,China [2]Beijing Baijiatuan Earth Sciences National Observation and Research Station,Beijing 100095,China [3]The First Monitoring and Application Center,China Earthquake Administration,Tianjin 300180,China

出　　处：《Earthquake Science》2021年第3期211-221,共11页地震学报（英文版）

基　　金：the National Natural Science Foundation of China(Nos.41974095,41774090,and U1939205);the Special Fund of the Institute of Geophysics,China Earthquake Administration(Nos.DQJB20X09,and DQJB21R30);The first author acknowledges support from the China Postdoctoral Science Foundation(No.2018M641424)。

摘　　要：The terrestrial time-variable gravity measurements are characterized by a high signal-to-noise ratio and sensitivity to the sources of mass change in the Earth's crust.These gravity data have many applications,such as surface deformation,groundwater storage changes,and mass migration before and after earthquakes.Based on repeated terrestrial gravity measurements at 198 gravity stations in the Sichuan-Yunnan region(SYR)from 2015 to 2017,we determine a time series of degree 120 gravity fields using the localized spherical harmonic(Slepian)basis functions.Our results show that adopting the first 6 Slepian basis functions is sufficient for effective localized Slepian modeling in the SYR.The differences between two gravity campaigns at the same time of year show an obvious correlation with tectonic features.The degree 120 timevariable gravity models presented in this paper will benefit the study of the regional mass migration inside the crust of the SYR and supplement the existing geophysical models for the China Seismic Experimental Site.

关 键 词：Sichuan-Yunnan region terrestrial gravity measurements time-variable gravity Slepian basis function regional gravity field 

分 类 号：P223[天文地球—大地测量学与测量工程] P315.7[天文地球—测绘科学与技术]