Japan Geoscience Union Meeting 2015

Presentation information


Symbol P (Space and Planetary Sciences) » P-PS Planetary Sciences

[P-PS21] Planetary Sciences

Mon. May 25, 2015 11:00 AM - 12:45 PM A02 (APA HOTEL&RESORT TOKYO BAY MAKUHARI)

Convener:*Kosuke Kurosawa(Planetary Exploration Research Center, Chiba Institute of Technology), Keiko Hamano(Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo), Chair:Shunichi Kamata(Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo), Shintaro Azuma(Department of Earth and Planetary Sciences System,Hiroshima university)

11:15 AM - 11:30 AM

[PPS21-34] Tidal resonance in icy satellites with subsurface oceans

*Shunichi KAMATA1, Isamu Matsuyama2, Francis Nimmo3 (1.Hokkaido Univ., 2.LPL/Univ. Arizona, 3.UC Santa Cruz)

Keywords:Icy satellites, Subsurface ocean, Tidal response, Resonance

Tidal dissipation is a major heat source for the icy satellites of the giant planets. Several icy satellites likely possess a subsurface ocean underneath an ice shell. Previous studies of tidal dissipation on icy satellites, however, have either assumed a static ocean, or ignored the effect of an ice lid on subsurface ocean dynamics. In this study, we extend the formulation for tidal deformation based on the viscoelasto-gravitational theory to incorporate inertial effects and obtain a comprehensive equation system that can be applied to a model with a dynamic ocean overlain by an ice lid. Although ocean dynamics are treated in a simplified fashion, we find a resonant configuration when the phase velocity of gravity waves approaches the orbital velocity. The enhanced deformation near the resonant configuration would lead to significantly enhanced tidal heating in the solid lid. A static ocean formulation would give an accurate result only if the ocean thickness is larger than the resonant thickness by a factor of about one hundred. The resonant configuration strongly depends on properties of the shell, demonstrating the importance of the presence of a shell on tidal dissipation.