USA, Alaska:

The Biggest Bang of the 20th Century: The 1912 Eruption of Novarupta in Alaska (Wired.com)

A schematic of the magmatic plumbing for the 1912 Novarupta 
eruption. Figure 158 from Hildreth and Fierstein (2012). 
(Courtesy Wired.com)

Today (June 6) marks the 100th anniversary of the largest eruption of the 20th century, yet many people have never ever 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!

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