Cryovolcanism

Cryovolcanism has been either observed on or suspected for numerous icy bodies across the Solar System, most notably Saturn’s tiny moon Enceladus, where jets of water vapor and other constituents are spewed into space from giant fractures near the South Pole. In this chapter, we review cryomagmatism and cryovolcanism, which are the subsurface and surface processes, respectively, resulting from the mobilization and migration of fluids generated in the interiors of icy bodies. Although these phenomena have no direct equivalents on Earth, they are important processes in the icy Solar System, and we can draw inferences as to how they operate from silicate volcanism in the inner Solar System. We discuss mechanisms of cryomagmatism and cryovolcanism, the possible compositions of cryomagmas, and the observational evidence found so far on extraterrestrial bodies, which range from plumes to geological features interpreted as cryovolcanic in origin.