5th Swiss Geoscience Meeting, Geneva 2007
Simulations of convection and magmatic resurfacing in
Io
Crameri Fabio
Institut für Geophysik, ETHZ, Schafmattstrasse 30, CH-8093 Zürich
(fcrameri@student.ethz.ch)
Across Io’s lithosphere, like previous work showed, magmatic resurfacing is
thought to be the dominant process transporting the heat. Because of that and
the relatively high fraction of partial melt in the mantle, melting may also play an
important role in the heat transport of Io’s interior. The key objective of this work
was to know about the effects of magmatism on convection and on the
resurfacing. Therefore, highly viscous 2-D simulations of the mantle including
melt segregation have been run to determine scaling laws. These scaling laws
are for velocity, lateral temperature variations, lateral variations in heat flux and
magmatism.
In contrast to previous studies, the simulations show a thick rigid top layer,
which is strong enough to support the observed topography on Io and a less hot
bottom layer, which allows the model to be self consistent. Further, magmatism
rather than conduction compensates higher heat inputs by an increased
magmatic heat transport and thus leads to a faster resurfacing of the
crust/lithosphere.
REFERENCES
Monnereau, M., & Dubuffet, F. 2002: Is Io’s interior really molten?, Icarus 158,
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Moore, W.B. 2003: Tidal heating and convection in Io, J. Geophys. Res.,
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Tackley, P.J. 2001: Convection in Io's asthenosphere: Redistribution of Nonuniform tidal heating by mean flows, J. Geophys. Res. 106, 32971-32981.
Tackley, P.J., Schubert, G., Glatzmaier G.A., Schenk P., Ratcliffe J.T. & Matas
J.-P. 2001: Three-dimensional spherical simulations of mantle convection in Io,
Icarus 149, 79-93.