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Convection in the ice crusts of satellites and its effect on surface relief
Author(s) -
Golitsyn G. S.
Publication year - 1979
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/gl006i006p00466
Subject(s) - geology , convection , crust , tectonics , geophysics , erosion , reynolds number , atmospheric sciences , meteorology , geomorphology , seismology , physics , turbulence
Using our knowledge about convective processes and the heat flow estimated by Reynolds and Cassen (1979), we find for the outer Gailiean satellites that the mean temperature within the convecting ice crust is about 180°K. The time scale of convection, thought to be a measure of a period of tectonic activity, is of order 5 million years and the velocities of order of 1‐20 cm per year depending on the thickness of the convecting layers (50‐1000 km). The thickness of the conducting upper layer is estimated to be of order 30 km. Due to low temperatures T at the surface and strong dependence of the viscosity on T, the time scale of smaller topographic features is estimated after Johnson and McGetchin (1973) to be of order from several hundred million years to several billion years. It is proposed that comparatively short tectonic processes, repeating every few million years, may serve as an erosion factor in shaping the form of the surfaces.