RT Journal Article
T1 Heat flow, lenticulae spacing, and possibility of convectionin the ice shell of Europa
A1 Ruiz Pérez, Javier
A1 Tejero López, Rosa
AB Two opposing models to explain the geological features observed on Europa’s surface have been proposed. The thin-shell model statesthat the ice shell is only a few kilometers thick, transfers heat by conduction only, and can become locally thinner until it exposes anunderlying ocean on the satellite’s surface. According to the thick-shell model, the ice shell may be several tens of kilometers thick and havea lower convective layer, above which there is a cold stagnant lid that dissipates heat by conduction. Whichever the case, from magneticdata there is strong support for the presence of a layer of salty liquid water under the ice. The present study was performed to examinewhether the possibility of convection is theoretically consistent with surface heat flows of 100–200 mW m2, deduced from a thin brittlelithosphere, and with the typical spacing of 15–23 km proposed for the features usually known as lenticulae. It was obtained that underEuropa’s ice shell conditions convection could occur and also account for high heat flows due to tidal heating of the convective (nearlyisothermal) interior, but only if the dominant water ice rheology is superplastic flow (with activation energy of 49 kJ mol1; this is therheology thought dominant in the warm interior of the ice shell). In this case the ice shell would be 15–50 km thick. Furthermore, in thisscenario explaining the origin of the lenticulae related to convective processes requires ice grain size close to 1 mm and ice thickness around 15–20 km.
PB Rosen Pub. Group
SN 1054-1381
YR 2003
FD 2003
LK https://hdl.handle.net/20.500.14352/56772
UL https://hdl.handle.net/20.500.14352/56772
LA eng
DS Docta Complutense
RD 21 sept 2024