View from the north rim of Katmai Caldera, a collapse feature
that formed during the catastrophic eruption in June of 1912.
Katmai Caldera is partially filled by a blue-green lake that is
more than 800 feet deep. Credit: R. McGimsey, U.S. Geological
Survey, Alaska Volcano Observatory and the
U.S. Geological Survey.
This column is provided as a public service by the Geophysical Institute, University of Alaska Fairbanks, in cooperation with the UAF research community. Ned Rozell is a science writer at the institute.
Super eruptions are disasters like none other.
Earth is pocked with giant craters that are reminders of a natural hazard that has happened before, and hopefully won’t happen again any time soon — the “super eruption.”
Stephen Self, a volcano researcher from Open University in England, was in Fairbanks recently to lecture on super eruptions. The last super eruption happened in 1815, when a tropical volcano named Tambora exploded for two days, leaving behind a giant caldera and pumping so much ash and sulfur dioxide into the atmosphere that 100,000 people died the year after the eruption. The ash and gases didn’t kill them, but the volcano’s affect on the atmosphere did. In many areas of Europe, crops failed to grow that year in the low light conditions.
Temperatures in London were 5-to-8 °Celsius cooler in 1816, Self said. “It was the ‘Year Without a Summer’ in the northeastern U.S., a year that inspired people to move West.”
Super eruptions don’t happen often, but they have been much larger than the Tambora eruption. An eruption in about AD 1452 was twice the size of Tambora, and both Long Valley Caldera (California) and Yellowstone (Wyoming and Idaho) are the earthly scars of super eruptions that affected large areas with their ashfall and lingering effects on the atmosphere.
“Yellowstone covered a large portion of the Lower 48,” Self said. “If another of these should occur, an entire country could be covered by ash.”
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