More information on the May 21 eruption of Grímsvötn in Iceland

As many of you know, today we saw a new eruption at Grímsvötn under Vatnajökull in Iceland - its first eruption since 2004 … and boy, it was a doozy. Reports have the ash plume reaching upwards of 15 (possibly 20) km / 50-65,000 feet (see below or top left), making it possibly the tallest eruption plume in Iceland since the 1947 eruption of Hekla. The eruption seems to be centered under the Grímsfjall Crater, where magma reaching the surface would have access to a lot of water, adding to the explosively of the eruption itself - which is typical for Grímsvötn based on its previous activity. However, this eruption appears to be larger than the 2004 eruption. Of course, after Eyjafjallajökull last year, everyone is watching the ash very closely, but there are at least some second hand reports that the ash is much coarser than the Eyjafjallajökull ash, so much less of a threat to stay in the air and disrupt air traffic over Europe. Even the no-fly zone around the volcano is relatively small compared to the 2010 Eyjafjallajökull eruption (so far). The latest London VAAC ash models show the ash mostly around Iceland and in the North Atlantic. However, there has been heavy ash fall reported in many places in Iceland itself.