New eruption of the subglacial Grímsvötn volcano began around 18-19 GMT on 21. May 2011. The eruption plume reached up to 17 km, higher maybe than in any eruption in Iceland since the 1947 eruption of Hekla. Video clip of the eruption here, and photograph from Þórdís Högnadóttir from afar. See our institute’s homepage for information.
Recent National Geographic Channel documentary describes research on interior of Icelandic volcanoes, including an expedition into the crater cave of Thrihnukagigur, a 200 m deep cave right into the topmost part of an active volcano plumbing system. Me and Haraldur Sigurðsson joined to explore the geology. See photos and videos here. May 3 coverage and more photos in Daily Mail: Here
A paper entitled “Intrusion triggering of the Eyjafjallajökull explosive eruption” was published in Nature last november. Magmatic movements of the volcano have been measured in details with GPS geodesy and satellite radar interferometry and interpreted in terms of magma movements in a complicated plumbing system under the volcano. Nature podcast interview here with Freysteinn.