Looks like the Grimsvötn volcano in Iceland has awakened and is now erupting vigorously. This is the one they were worried about last year when Eyjafjallajökul popped. There is no telling if this will be a big problem, or just a burp, but already the ash cloud has reached jet altitude, and airliners are being diverted around a 120km radius.

This is another of those volcanos that erupt under a large glacier, in this case the Vatnajökel. Such eruptions often cause a sudden and massive flood of water known as a Jökelhlaup. Not to worry, the Icelanders are used to these events and usually they are anticipated and no one is injured. It will be interesting to see if one happens this time, and if so the Youtube videos should be entertaining.