Evidence for the origin of ridges on Europa by means of photoclinometric data from E4 Galileo orbit

Abstract

The most commonly observable structures on the surface of the Jovian satellite Europa are the ridges. Geological evidences show that the ridges have been formed continuously for the last 10 million years. Understanding the mechanism that is originating the ridges is fundamental in order to know the geological history of the satellite, and in the search for liquid water under the icysurface of Europa. In this work, we show some evidence suggesting that the terrain adjacent to a crack was upwarped due to the formation of ridges. We conclude that neither the volcanic nor the tidal squeezing mechanisms seem to form ridges; however, it is very probable that diapirism or a similar process can form ridges.