Anybody with headsets or a good sound system hear that periodic rumble? I wonder how long until that area blows. Skyrim could look very different in that part of the map in the future.
That area is also in kind of a hole. Almost like a crater. There is going to be a huge eruption at some point. The same reason the USGS has their eye on Yellowstone National Park.
It's possible, the Mage at the College of Winterhold claim that 'we' could blow up half of Eastmarch and people would still come to him for enchanting services. But I don't think it's going to happen.