This caldera is named Tvashtar Catena and was imaged in 2000. Earlier in 1999 the region appeared as seen at below-left. Clearly the progress made in a volcanic year on Io is incredible… just for reference, 
the region pictured here is larger tha the Grand Canyon here on Earth. Imagine something that large here on Earth changing that much in one year.
Io stands alone in our Solar System in terms of geological activity, but an interesting relationship can be drawn from what is seen on Io and what is seen in Europa’s internal ocean. The same stresses coming from Jupiter which heat and tear Io apart are the same ones, which at a safer distance, internally heat Europa’s oceans. Leading us to believe that had Io been even closer to Jupiter its very stability would come into question. Looking further out at Ganymede, evidence suggests that it may as well experience some of this internal heating and could also contain a vast water ocean much further below a thinker icy crust than Europa. The right 1/3 of this image was generated based upon textures in the main image to the left (hence the lack of any details). So only the left 2/3 of this image is actual. I added the rest simply to fill out the proportion for the wallpaper. There may for all I know be a vast mountain range that begins in that area, but alas… i have depicted it as flat. But the rest is the real deal my friend.