Implications of shear heating and fracture zones for ridge formation on Europa

Abstract

We present 2D and 3D numerical simulations of convection to test the role of shear heating and fracture zones on Europan ridge formation. Our simulations show that a pre-existing fracture zone promotes upwelling and lithospheric thinning, leading to topographic uplift of 50 m. Shear heating also promotes lithospheric thinning and buoyant ascent, producing a ridge-like feature with topography up to 120 m. Topography remains linear along strike even under the influence of heterogeneous 3D convection within the ice shell. Although the central trough is not reproduced in the simulations, our results support the idea that shear heating can produce ridge-like structures on Europa. Copyright 2008 by the American Geophysical Union.