RT Journal Article
T1 Equilibrium Convection on a Tidally Heatedand Stressed Icy Shell of Europa for a CompositeWater Ice Rheology
A1 Ruiz Pérez, Javier
AB Water ice I rheology is a key factor for understanding the thermal and mechanicalstate of the outer shell of the icy satellites. Ice flow involves several deformation mechanisms(both Newtonian and non-Newtonian), which contribute to different extents depending onthe temperature, grain size, and applied stress. In this work I analyze tidally heated andstressed equilibrium convection in the ice shell of Europa by considering a compositeviscosity law which includes diffusion creep, basal slip, grain boundary sliding and dislocationcreep, and. The calculations take into account the effect of tidal stresses on ice flowand use grain sizes between 0.1 and 100 mm. An Arrhenius-type relation (useful forparameterized convective models) is found then by fitting the calculated viscosity between170 and 273 K to an exponential regression, which can be expressed in terms of preexponentialconstant and effective activation energy. I obtain convective heat flows between*40 and *60 mW m-2, values lower than those usually deduced (*100 mW m-2) fromgeological indicators of lithospheric thermal state, probably indicating heterogeneous tidalheating. On the other hand, for grain sizes larger than *0.3 mm the thicknesses of the iceshell and convective sublayer are*20–30 km and*5–20 km respectively, values in goodagreement with the available information for Europa. So, some fundamental geophysicalcharacteristics of the ice shell of Europa could be arising from the properties of the compositewater ice rheology.
PB Springer Science Business Media
SN 0167-9295
YR 2010
FD 2010
LK https://hdl.handle.net/20.500.14352/42351
UL https://hdl.handle.net/20.500.14352/42351
LA eng
DS Docta Complutense
RD 18 abr 2025