Global Glacial Isostatic Adjustment Constrained by GPS Measurements: Spherical Harmonic Analyses of Uplifts and Geopotential Variations

Remote Sensing

Yong Huang¹  Yan Zhou¹  Jiancheng Li²  Jiesi Luo²  Jim Ray³  Shaomin Yang⁴ 

[1] Key Laboratory of Earthquake Geodesy, Institute of Seismology, China Earthquake Administration, Wuhan 430071, China;Key Laboratory of Geospace Environment and Geodesy, School of Geodesy and Geomatics, Wuhan University, Wuhan 430079, China;National Oceanic and Atmospheric Administration (retired), Silver Spring, MD 20910, USA;Wuhan Emergency Management Bureau, Wuhan 430010, China;

关键词: glacial isostatic adjustment;    vertical crustal deformation;    GPS;    geopotential;    GRACE;   

DOI  :  10.3390/rs12071209

来源: DOAJ

【 摘 要 】

In addition to studies of sea level change and mantle rheology, reliable Glacial Isostatic Adjustment (GIA) models are necessary as a background model to correct the widely used Gravity Recovery and Climate Experiment (GRACE) monthly gravity solutions to determine subsecular, nonviscous variations. Based on spherical harmonic analyses, we developed a method using degree-dependent weighting to assimilate the Global Positioning System (GPS) derived crustal uplift rates into GIA model predictions, in which the good global pattern of GIA model predictions and better local resolution of GPS solutions are both retained. Some systematic errors in global GPS uplift rates were also corrected during the spherical harmonic analyses. Further, we used the refined GIA uplift rates to infer the GIA-induced rates of Stokes coefficients (complete to degree/order 120) relying on the accurate relationship between GIA vertical surface deformation and gravitational potential changes. The results show notable improvements relative to GIA model outputs, and may serve as a GIA-correction model for GRACE time-variable gravity data.

【 授权许可】

Unknown