Abstract
We investigate the tidal dissipation in Io’s hypothetical fluid magma
ocean using a new approach based on the solution of the 3D Navier-Stokes
equations. Our results indicate that Io may have experienced a period of
intense tidal heating (104 TW) accompanied by excessive volcanism in the
equatorial region, leading to catastrophic resurfacing of the
pre-existing terrain. Tidal heating in Io’s magma ocean does not
correlate with the distribution of hot spots, and is maximum for an
ocean thickness of about 1 km and a viscosity of less than 104 Pa s. Due
to the Coriolis effect, the k2 Love number can depend on the harmonic
order. We show that the analysis of k2 may not reveal the presence of a
fluid magma ocean if the ocean thickness is less than 2 km. If the fluid
layer is thicker than 2 km, k20 ≈ k22/2 ≈ 0.7.