1 results
7 - Tectonics of the outer planet satellites
-
- By Geoffrey C. Collins, Wheaton College, Norton, William B. McKinnon, Washington University, Saint Louis, Jeffrey M. Moore, NASA Ames Research Center, Moffett Field, Francis Nimmo, University of California, Santa Cruz, Robert T. Pappalardo, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, Louise M. Prockter, Applied Physics Laboratory, Laurel, Paul M. Schenk, Lunar and Planetary Institute, Houston
- Edited by Thomas R. Watters, Smithsonian Institution, Washington DC, Richard A. Schultz, University of Nevada, Reno
-
- Book:
- Planetary Tectonics
- Published online:
- 30 March 2010
- Print publication:
- 17 December 2009, pp 264-350
-
- Chapter
- Export citation
-
Summary
Summary
Tectonic features on the satellites of the outer planets range from the familiar, such as clearly recognizable graben on many satellites, to the bizarre, such as the ubiquitous double ridges on Europa, the twisting sets of ridges on Triton, or the isolated giant mountains rising from Io's surface. All of the large and middle-sized outer planet satellites except Io are dominated by water ice near their surfaces. Though ice is a brittle material at the cold temperatures found in the outer solar system, the amount of energy it takes to bring it close to its melting point is lower than for a rocky body. Therefore, some unique features of icy satellite tectonics may be influenced by a near-surface ductile layer beneath the brittle surface material, and several of the icy satellites may possess subsurface oceans. Sources of stress to drive tectonism are commonly dominated by the tides that deform these satellites as they orbit their primary giant planets. On several satellites, the observed tectonic features may be the result of changes in their tidal figures, or motions of their solid surfaces with respect to their tidal figures. Other driving mechanisms for tectonics include volume changes due to ice or water phase changes in the interior, thermoelastic stress, deformation of the surface above rising diapirs of warm ice, and motion of subsurface material toward large impact basins as they fill in and relax.