Yes, I was aware of it, thanks though. That is why I mentioned the novel in the first place. Was going to mention the jökulls too, as sibling comment does. One of them was Vatna or some such, need to check - it was long back that I read it :)

Update: Checked, that's the name:

https://en.wikipedia.org/wiki/Vatnaj%C3%B6kull

Update 2: There are some interesting points in that Wikipedia article.