Spotted in advance by Jon Frimann over at his blog. He flagged up the tremor harmonics in advance of the Icelandic Met Office confirmation. Well spotted that man.
Ash plume has been confirmed at 2-3000 Metres and rising, although Grímsvötn has a history of short lived eruptions, the last one to get through the ice was in 2004. Constantly updated details, and perhaps webcams can be found via the excellent ‘Eruptions’ blog. Icelandic air traffic is being disrupted, although the plume seems to be heading North on the satellite images available. The plume is also said to be not likely to interrupt European air traffic like the April 2010 eruption of Mt Unpronounceable.
Volcano and seismic links will have their own sidebar shortly.