I'm not intending to poach on the great job Rei is doing keeping us updated on Bárðarbunga, but I just ran across an article by Jared Keller at World.Mic with some NASA imaging from space (and some ground shots) that are worth a look. (Vox has a write up as well.)
The NASA Earth Observatory page has more, including links to quite a few more images towards the bottom of the page.
And for a literal "Blast from the Past", NASA has a recap of Landsat's imaging of Mount St. Helens. Here's a montage over time showing the changes.
http://youtu.be/...
One of the biggest tools humanity has at its disposal is the ability to look at our world from space. We could be doing a far better trying to keep this planet livable if we'd pay more attention to what NASA and the ESA have to show us.