This is
interesting! Looks like the "fast" upwelling zones would be the best place
to search the surface ice for clues to the ocean composition. The center
fault of a "slow" rift might be the best place to punch through the
crust.
It's a little
disconcerting that Europa seems to be slowly solidifying. This may mean
any internal heating mechanisms, like volcanism, have ceased long ago. But
at least some surface compounds may be slowly, but consistently, reintroduced
due to subduction?
