Article,
Habitability of Europa's crust: The role of tidal-tectonic processes
Journal of Geophysical Research-Planets, 105 (E7): 17551--17562 (2000)
Abstract
Jupiter's satellite Europa has been identified as one of the most
likely sites for life in the solar system. The tidal-tectonic processes
that appear to have governed Europa's geology seem to require interaction
with an ocean under only a very thin crust, providing a variety of
evolving environmental niches. The mutually dependent relationship
between orbital evolution and tidal processes in turn controls Europa's
rotation, heating, and stress. Surface lineaments are correlated
with global stress patterns, demonstrating that they form by crustal
cracking, but only if a substantial ocean is present to give adequate
tidal amplitude. Tidal driving of strike-slip faulting indicates
that cracks penetrate to a fluid layer, which is possible only with
a very thin ice crust. The characteristic ridge sets that cover tectonic
terrain are likely built by tidal pumping of fluid and slush to the
surface on a daily basis. Widespread tectonic dilation creates new
surface as material rises from below. Chaotic terrain has morphology
and other characteristics indicative of melt-through from below.
Surface colorants correlate with locations, such as along large-scale
ridge systems and around chaotic terrain, where ocean water reached
the surface. This model implies that as a result of tides, liquid
water regularly bathed crustal cracks and surfaces with heat and
whatever nutrients are included in the oceanic chemistry, creating
a variety of habitable environments. The processes were recent and
thus most likely continue today. Longer-term evolution of environmental
conditions provided the need for adaptation and opportunity for evolution.
Tags
- europa;
- evolution;
- features;
- galilean
- ganymede;
- ice
- jupiter
- moon
- nonsynchronous
- patterns;
- rotation;
- satellites;
- shell;
- stresses;
