stressface:

The Biggest Bang of the 20th Century: The 1912 Eruption of Novarupta in Alaska

[June 6, 2012 marked] the 100th anniversary of the largest eruption of the 20th century, yet many people have never even heard its name. In fact, the name was wrong for almost half a century! What is known as the Novarupta or Katmai eruption of 1912 was huge – ejecting almost 30 cubic kilometers of ash and debris into the atmosphere or along the ground as pyroclastic flows. That represents ~13 cubic kilometers of magma (once you correct for all the air in ash) erupted over the course of ~60 hours. That is a rate of nearly 220 million cubic meters per hour, which is roughly 520 million tonnes per hour – or to put it another way, that is ~5,300 Nimitz-class aircraft carriers per hour. Now that is an eruption!

Read the blow-by-blow of the eruption here.