Novarupta, meaning "new eruption", is a volcano

Volcano

2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...

 located on the Alaska Peninsula

Alaska Peninsula

The Alaska Peninsula is a peninsula extending about to the southwest from the mainland of Alaska and ending in the Aleutian Islands. The peninsula separates the Pacific Ocean from Bristol Bay, an arm of the Bering Sea....

 in Katmai National Park and Preserve

Katmai National Park and Preserve

Katmai National Park and Preserve is a United States National Park in southern Alaska, notable for the Valley of Ten Thousand Smokes and for its brown bears. The park covers , being roughly the size of Wales. Most of this is a designated wilderness area, including of the park...

, about 290 miles (466.7 km) southwest of Anchorage

Anchorage, Alaska

Anchorage is a unified home rule municipality in the southcentral part of the U.S. state of Alaska. It is the northernmost major city in the United States...

. Formed in 1912 during the largest volcanic eruption of the 20th century, Novarupta released 30 times the volume of magma

Magma

Magma is a mixture of molten rock, volatiles and solids that is found beneath the surface of the Earth, and is expected to exist on other terrestrial planets. Besides molten rock, magma may also contain suspended crystals and dissolved gas and sometimes also gas bubbles. Magma often collects in...

 as the 1980 eruption of Mount St. Helens

1980 eruption of Mount St. Helens

The 1980 eruption of Mount St. Helens, a stratovolcano located in Washington state, in the United States, was a major volcanic eruption. The eruption was the only significant one to occur in the contiguous 48 U.S. states since the 1915 eruption of Lassen Peak in California...

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The largest eruption of the 20th century occurred in 1912, from June 6 to June 8, to form Novarupta. Rated a 6 on the volcanic explosivity index

Volcanic Explosivity Index

The Volcanic Explosivity Index was devised by Chris Newhall of the U.S. Geological Survey and Stephen Self at the University of Hawaii in 1982 to provide a relative measure of the explosiveness of volcanic eruptions....

, the 60 hour long eruption expelled 13 to 15 km³ (3.1 to 3.6 cumi) of magma, 30 times as much as the 1980 eruption of Mount St. Helens

1980 eruption of Mount St. Helens

The 1980 eruption of Mount St. Helens, a stratovolcano located in Washington state, in the United States, was a major volcanic eruption. The eruption was the only significant one to occur in the contiguous 48 U.S. states since the 1915 eruption of Lassen Peak in California...

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