The as-of-yet-unnamed eruption north of the Vatnajökull glacier has reached a higher category on the Volcanic Explosivity Index (VEI) and is now considered to be VEI 5 . Such eruptions are rare and on average tend to occur once every ten years or so.As a result the caldera under the Dyngjujökull glacier is now comparable to some of the most famous volcanic eruptions in human history, for example the Vesuvius eruption in 79 A.D. that destroyed the city of Pompeii and the eruption of St. Helens in 1980 in Washington State in the U.S. which killed 57 people.The VEI was made by the U.S. Geological Survey and is based on the volume of volcanic products from the eruption. In the next category above, VEI 6, we find the Krakatoa eruption of 1883 and the Pinatubo eruption of 1991. Above that, in VEI 7, we have the Tambora Eruption of 1815, the most destructive eruption in the recorded history of mankind. Mankind has yet to witness a VEI 8 eruption, the highest category there is, but among those is counted an eruption under Yellowstone Park which is believed to have occurred around 640 thousand years ago.In the next category below, VEI 4, we can find many known eruptions, among them the Eyjafjallajökull eruption of 2010.