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Poroviscoelastic Gravitational Dynamics
| Title: | Poroviscoelastic Gravitational Dynamics |
| Authors: | Kamata, Shunichi Browse this author →KAKEN DB |
| Keywords: | geodynamics | | viscoelasticity | | poroelasticity | | tidal deformation | | tidal heating |
| Issue Date: | Jul-2023 |
| Publisher: | American Geophysical Union |
| Journal Title: | Journal of Geophysical Research Planets |
| Volume: | 128 |
| Issue: | 7 |
| Publisher DOI: | 10.1029/2022JE007700 |
| Abstract: | Global-scale periodic deformation has been studied using the (visco)elastic gravitational theory, which assumes a planetary body consists of solid or liquid layers. Recent planetary exploration missions, however, suggest that a global layer of a mixture of solid and liquid exists in several planetary bodies. This study provides a theory of periodic deformation of such a layer unifying the viscoelastic gravitational theory with the theory of poroelasticity without introducing additional constraints. The governing equation system and a formulation suitable for numerical calculation are given. Equations used to calculate the energy dissipation rate are also given. The analytical solutions for a homogeneous sphere are obtained using an eigenvalue approach. Simple numerical calculations assuming a homogeneous sphere reveal that a numerical instability occurs if a thick porous layer, a low permeability, or a high frequency is assumed. This instability can be avoided by choosing an appropriate interior structure model that is numerically equivalent. Different simple numerical calculations adopting a multilayered, radially varying interior profile reveal that the radial profile of the tidal heating rate for a fluid-saturated porous layer and that for a low-viscosity solid layer are completely different. In addition, the radial variation in porosity can lead to a factor of similar to 100 increase in the local heating rate. These results indicate that future studies should consider a wider variety of detailed interior structure models. |
| Rights: | Copyright 2023 American Geophysical Union. |
| Type: | article |
| URI: | http://hdl.handle.net/2115/91055 |
| Appears in Collections: | 理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 鎌田 俊一
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