Mathematics – Logic
Scientific paper
Apr 2003
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003eaeja....11297h&link_type=abstract
EGS - AGU - EUG Joint Assembly, Abstracts from the meeting held in Nice, France, 6 - 11 April 2003, abstract #11297
Mathematics
Logic
Scientific paper
Thermal-orbital histories of Io and Europa are presented, assuming that the three inner Galilean satellites Io, Europa, and Ganymede evolve in the Laplace resonance. Tidal dissipation of orbital energy is an internal heat source for both Io and Europa. Ganymede's tidal heating rate is small compared to radiogenic heating and it is therefore neglected. While dissipation in Io is assumed to occur in the mantle, two models are considered for Europa. In the first model dissipation occurs in the silicate mantle while in the second model dissipation occurs in the ice shell. In the latter model, ice shell melting and variations of the shell thickness above an ocean are explicitly included. The rheology of both the ice and the rock is cast in terms of a viscoelastic Maxwell rheology with viscosity and shear modulus depending on the average temperature of the dissipating layer. Heat transfer by convection is calculated using a parameterization for strongly temperature dependent viscosity convection. Both models are consistent with the present orbital elements of Io, Europa, and Ganymede and give a present day surface heat flow for Io of about 2 Wm-2. It is shown that there may be phases of quasi-steady evolution with large or small dissipation rates (in comparison with radiogenic heating), phases with runaway heating or cooling and oscillatory phases during which the eccentricity and the tidal heating rate will oscillate. The occurrence and duration of these phases depend on the rheology, the temperature in both satellites and the Jovian dissipation factor. The excursions in the tidal heating rate for Europa may reach 1013 W, which is about an order of magnitude smaller than Io's present value. The difference is due to the larger orbital distance and smaller size of Europa. The orbits of the two satellites are presently expanding in the model with dissipation in Europa's silicate layer. For the model with dissipation in the ice shell both Io and Europa are found in the oscillatory regime and Io is presently moving inward towards Jupiter. The ice shell thickness in this model oscillates between 10 and 60 km, suggesting that Europa's ocean existed for geological timescales. The oscillation period is about 140 Ma. According to this model, the present value of the shell thickness is about 30 km and is increasing. The surface heat flow is about 0.020 Wm-2. The different dissipative phases may be closely related to individual geological surface features on Europa.
Hussmann Hauke
Spohn Tilman
No associations
LandOfFree
Io-like tidal heating rates in Europa derived from coupled thermal-orbital evolution models does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Io-like tidal heating rates in Europa derived from coupled thermal-orbital evolution models, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Io-like tidal heating rates in Europa derived from coupled thermal-orbital evolution models will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-844985