Is There Evidence for Polar Wander on Europa?

Computer Science

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

66

Scientific paper

The orientations of the albedo lineaments, bands, and lineations on Europa's surface have been compared in previous studies with the global stress fields set up by orbital eccentricity, orbital recession, and nonsynchronous rotation. Of these orbital and rotational effects, nonsynchronous rotation, combined with an offsetting of the tidal bulge, comes closest to providing agreement between the stress field generated and the lineation orientations, if the lineations trace tension or extension fractures (McEwen 1986. Nature 321, 49-51). However, inferred minimum principal stress directions for a broad region of wedge-shaped bands near the anti-Jove point cannot satisfactorily be accounted for by any of the stress fields above, but are consistent with the stresses resulting from a rotation of Europa's ice shell about an axis through the sub- and anti-Jove points, clockwise as seen from the anti-Jove hemisphere (P. M. Schenk and W. B. McKinnon 1989. Icarus 79, 75-100). Calculations by Ojakangas and Stevenson (1989. Icarus 81, 220-241) of the thermal state of Europa's ice shell indicate that spatial variations in the thickness of the shell may cause it to undergo such a reorientation. We have investigated whether any reorientation of the shell about an axis through the sub- and anti-Jove points produces a stress field consistent with the full, global set of prominent lineations on Europa's surface. We find that no such reorientation provides a good fit between the lineations and plausible fracture orientations derived from the principal stress trajectories. Topographic ridges, identified in a limited zone south of the anti-Jove point, are roughly consistent with compression due to clockwise polar wander, but the orientations of these ridges may be strongly biased by illumination direction. Within the limitations of the presently available imagery, nonsynchronous rotation is still the most likely cause of the prominant fractures on Europa's surface, and the best specific, albeit regionally limited, tectonic evidence consistent with recent polar wander remains the wedge-shaped bands.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Is There Evidence for Polar Wander on Europa? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Is There Evidence for Polar Wander on Europa?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Is There Evidence for Polar Wander on Europa? will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1336899

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.