Subsurface Water Oceans on Icy Satellites: Chemical Composition and Exchange Processes
Source: Space Science Reviews, Volume 153, Numbers 1-4, June 2010 , pp. 485-510(26)
Abstract:The state of knowledge about the structure and composition of icy satellite interiors has been significantly extended by combining direct measurements from spacecraft, laboratory experiments, and theoretical modeling. The existence of potentially habitable liquid water reservoirs on icy satellites is dependent on the radiogenic heating of the rock component, additional contributions such as the dissipation of tidal energy, the efficiency of heat transfer to the surface, and the presence of substances that deplete the freezing point of liquid water. This review summarizes the chemical evolution of subsurface liquid water oceans, taking into account a number of chemical processes occuring in aqueous environments and partly related to material exchange with the deep interior. Of interest are processes occuring at the transitions from the liquid water layer to the ice layers above and below, involving the possible formation of clathrate hydrates and high-pressure ices on large icy satellites. In contrast, water-rock exchange is important for the chemical evolution of the liquid water layer if the latter is in contact with ocean floor rock on small satellites. The composition of oceanic floor deposits depends on ambient physical conditions and ocean chemistry, and their evolutions through time. In turn, physical properties of the ocean floor affect the circulation of oceanic water and related thermal effects due to tidally-induced porous flow and aqueous alteration of ocean floor rock.
Keywords: Callisto; Chemical evolution; Clathrate hydrates; Enceladus; Europa; Ganymede; High-pressure ices; Hydrothermal activity; Oceanic composition; Organic compounds; Outer solar system; Porous rock; Serpentinization; Titan; Water oceans
Document Type: Research Article
Affiliations: 1: Institute of Planetary Research, German Aerospace Center (DLR), Rutherfordstr. 2, 12489, Berlin, Germany, Email: email@example.com 2: Jet Propulsion Laboratory, Caltech, MS 79-24, 4800 Oak Grove Drive, Pasadena, CA, 91106, USA, Email: firstname.lastname@example.org 3: Department of Hydrology, University of Arizona, Tuscon, AZ, 85721, USA, Email: email@example.com 4: Department of Cosmosciences, Hokkaido University, Nishi 8, Kita 10, Kita-Ku, Sapporo, 060-0810, Japan, Email: firstname.lastname@example.org 5: Jet Propulsion Laboratory, Caltech, MS 79-24, 4800 Oak Grove Drive, Pasadena, CA, 91106, USA, Email: email@example.com 6: Jet Propulsion Laboratory, Caltech, MS 79-24, 4800 Oak Grove Drive, Pasadena, CA, 91106, USA, Email: firstname.lastname@example.org 7: School of Earth and Space Exploration, Arizona State University, Tempe, AZ, 85287-1404, USA, Email: email@example.com
Publication date: June 1, 2010