Publication Date:
2016-07-14
Description:
Tidal deformation of icy satellites provides crucial information on their subsurface structures. In this study, we investigate the parameter dependence of the tidal displacement and potential Love numbers (i.e., h 2 and k 2 , respectively) of Ganymede. Our results indicate that Love numbers for Ganymede models without a subsurface ocean are not necessarily smaller than those with a subsurface ocean. The phase lag, however, depends primarily on the presence/absence of a subsurface ocean. Thus, the determination of the phase lag would be of importance to infer whether Ganymede possesses a subsurface ocean or not based only on geodetic measurements. Our results also indicate that the major control on Love numbers is the thickness of the ice shell if Ganymede possesses a subsurface ocean. This result, however, does not necessarily indicate that measurement of either of h 2 or k 2 alone is sufficient to estimate the shell thickness; while a thin shell leads to large h 2 and k 2 independent of parameters, a thick shell does not necessarily lead to small h 2 and k 2 . We found that, to reduce the uncertainty in the shell thickness, constraining k 2 in addition to h 2 is necessary, highlighting the importance of collaborative analyses of topography and gravity field data.
Print ISSN:
0148-0227
Topics:
Geosciences
,
Physics
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