Remember back in 1980 when Mount St Helens blew up and all that ash…what a mess. Well according to vulcanologists that was sort of sneeze compared to the 1912 explosion of Novarupta up in Alaska.  That was the largest eruption of the 20th century.  Lots of ash and smoke spread over a large area. The land shook with at least fourteen earthquakes of magnitude 6 or higher. More than 13.5 cubic kilometers (3 cubic miles) of molten rock, or magma, blasted out of the Earth. Another 17 cubic kilometers of ash and volcanic debris spewed into the air or rolled across the hillside in pyroclastic flows. And it all happened in a matter of 60 hours.

“That is a rate of nearly 220 million cubic meters per hour, which is roughly 520 million tons per hour,” wrote volcanologist and blogger Erik Klemetti. “Or to put it another way, that is about 5,300 Nimitz-class aircraft carriers per hour. Now that is an eruption!”

Earlier this week a lack of snow and high winds stirred up that ash from 100 years ago and created a haze over Katmai National Park and Preserve. The haze was so thick aircraft were warned to avoid the area.