Solid-State Ice Volcanism on the Satellites of Uranus
DAVID G. JANKOWSKI 1 and
STEVEN W. SQUYRES 1
1 Center for Radiophysics and Space Research, Cornell University, Ithaca, NY 14853.
Voyager images of the uranian satellites Ariel and Miranda show flow features with morphologies indicating that ice has been extruded to the satellites' surfaces in the solid state. These images provide the first observational evidence for solid-state ice volcanism in the solar system. Topographic profiles have been measured across a number of flow features on Ariel. With a simple model of extrusion, spreading, and cooling of a viscous flow, the initial viscosity of the flow material is found to have been no more than about 1016 poise, far lower than expected for H2O ice at the ambient surface temperatures in the uranian system. Sharply reduced viscosities may have resulted from incorporation of ices like NH3 or CH4 in the uranian satellites.
Submitted on March 21, 1988
Accepted on July 19, 1988
