JpGU-AGU Joint Meeting 2020

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[J] Poster

S (Solid Earth Sciences ) » S-GD Geodesy

[S-GD02] Geodesy

convener:Koji Matsuo(Geospatial Information Authority of Japan), Yusuke Yokota(Institute of Industrial Science, The University of Tokyo), Daisuke Oka(Geological Survey of Hokkaido, Environmental and Geological Research Department, Local Independent Administrative Agency, Hokkaido Research Organization)

[SGD02-P08] Calculation method of the compliance parameters of the Earth's rotation: Influence of the fluid core and the solid inner core

*Yuji Harada1,2, Shuhei Okubo3,4 (1.State Key Laboratory of Lunar and Planetary Science, Space Science Institute, Macau University of Science and Technology, 2.Ocean Hemisphere Research Center, Earthquake Research Institute, University of Tokyo, 3.Department of Surveying and Geoinformatics, Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, 4.University of Tokyo)

Keywords:Earth's rotation, Earth's tide, Earth's interior

Effect of non-rigidity of the solid Earth exerted on the tide and rotation is significant for understanding dynamical behavior of the core and mantle. The influence of the fluid core on the Earth's rotational motion is predictable with high precision based on the semi-analytic theory developed by Sasao et al. (the so-called Sasao-Okubo-Saito theory). This theory was expanded afterward into the theory incorporating not only the influence of the fluid core but also that of the solid inner core through a series of theoretical studies by Mathews et al. (the so-called Mathews-Herring-Buffett theory). Within the previous papers completing these SOS and MHB theories, however, there may exist a few unexplicit parts in terms of numerical procedures. It is considered to be valuable to re-definitize the above-mentioned semi-analytic theory. The present study, therefore, describes how to compute each of the important parameters included in the SOS and MHB theories semi-analytically by means of Saito's calculation method of quasi-static deformation in as much detail as possible. As a result of the computation, most of the individual parameters listed in the previous studies can be reproduced almost perfectly.

This work was financially supported by the Research Funding Projects (No. 007/2016/A1, No. 043/2016/A2, No. 119/2017/A3, and No. 187/2017/A3) at the Science and Technology Development Fund, the Macau Special Administrative Region.