Premium
Causes, characteristics and consequences of convective diapirism on Europa
Author(s) -
Nimmo Francis,
Manga Michael
Publication year - 2002
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2002gl015754
Subject(s) - diapir , geology , dome (geology) , convection , heat flux , flux (metallurgy) , viscosity , thermal , geophysics , upwelling , diffusion , mechanics , heat transfer , thermodynamics , materials science , geomorphology , tectonics , seismology , physics , oceanography , metallurgy
We investigate the hypothesis that the ∼10 km diameter dome‐shaped features seen on Europa's surface are caused by strongly temperature‐dependent convection, in which upwellings form isolated diapirs or thermals. We use the observed lower limit on dome diameter of 4 km to deduce that the conductive (stagnant) lid thickness must be ≤5 km. Such a lid thickness implies a minimum surface heat flux of 90 mWm −2 , compatible with recent estimates of tidal heating. We also use the mean observed dome diameter to infer a lower thermal boundary layer thickness of ∼1 km. We find that the ice is probably deforming in the diffusion creep regime with a grain size in the range 0.02–0.06 mm. The fraction of internal heating is >0.5, the ice viscosity 10 12 –10 13 Pa s, and the crustal solidification rate<5km/Ma.