Open AccessHeat flows through the ice lithosphere of Europa
Author(s) -
Ruiz Javier,
Tejero Rosa
Publication year - 2000
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/1999je001228
Subject(s) - geology , lithosphere , convection , brittleness , geophysics , grain size , flow (mathematics) , petrology , mechanics , geomorphology , tectonics , seismology , materials science , physics , composite material
Some of the geological features on the surface of Europa's ice shell suggest the existence of a brittle lithosphere that in some regions is no more than 2 km thick. The surface heat flow needed to put the brittle‐ductile transition in ice at a depth of 2 km is at least ∼100 mW m −2 , much higher than predicted by tidal heating models for a purely conductive ice shell. A possible explanation lies in the probable existence of a convective layer beneath the brittle lithosphere, which, owing to tidal dissipation in warm ice, could contribute to higher heat flows. If a convective subsurface layer and grain size dependent flow behavior of ice are admitted, the grain size at brittle‐ductile transition depth cannot be >1 mm, which is consistent with the required value for the onset of convection in an ice shell thinner than 20 km.