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Volume changes in Ganymede and Callisto and the origin of grooved terrain
Author(s) -
Squyres Steven W.
Publication year - 1980
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/gl007i008p00593
Subject(s) - terrain , crust , geology , convection , deformation (meteorology) , astrobiology , geophysics , petrology , mechanics , physics , ecology , oceanography , biology
Internal melting and differentiation of Ganymede and Callisto may have caused an increase in the surface area of these bodies early in their histories of up to 5‐7%. Subsequent refreezing of internal liquid water due to solid state convection in an ice crust should not have caused significant surface area changes. Expansion due to differentiation may have caused formation of grooved terrain on Ganymede. These calculations suggest that grooved terrain formation is essentially a replacement and/or deformation process, with no more than about 15% of grooved terrain actually being new material. The absence of grooved terrain on Callisto may be due to the effects of a thicker crust and a lower expansion rate.