What is a Super Volcano

Super volcanoes are a potential threat that would dwarf anything our civilization has ever faced. While the world frets over global warming, and movies are made about asteroids hitting the Earth, an eruption of a super volcano has barely been faced. But, then again, even if such were to occur there is likely nothing that we could do about it either in the way of prevention or preparation.

The difference between a super volcano and other volcanoes is one of scale. Most commonly known volcanoes have magma chambers, underground pools of molten rock, around .01 cubic kilometers. Super volcanoes, on the other hand, can have magma chambers many times that amount, as much as 1 cubic kilometer or more. While the term super volcano has no scientific meaning at this time there are a number of regions of the Earth that have the characteristics to merit the use of the term, and geological and paleontological evidence of prehistoric eruptions justify its use. The modern regions that may qualify as super volcanoes include Yellowstone in the Northwestern United States, Lake Taupo in New Zealand and Lake Toba in Indonesia.

The eruption of the Tambora Volcano in Indonesia, climaxing in 1815, was estimated to have caused as many as 82,000 deaths. Around 12,000 of those deaths were caused directly by the eruption while the majority were caused by climate change from the massive clouds of gas and dust introduced into the atmosphere. The year 1816 was known as the “Year Without Summer” resulting in extensive crop failures and starvation. The only worse death toll from a volcano in recorded history was due to the eruption of Nevado del Ruiz in Columbia in 1985. And the reason for that enormous death toll was due to the sudden destruction of a city of 28,000 people, not due to climate effects.

The eruption of Tambora ejected 100 cubic kilometers of lava and ash. When the magma chamber was emptied it resulted in a caldera, or collapse crater, about six kilometers in diameter. In comparison, the Yellowstone Caldera in the United States is approximately sixty kilometers in diameter.

With a magma chamber estimated to be 15,000 cubic kilometers, Yellowstone National Park is over an enormous super volcano. This could result in an eruption as much as one million times more devastating than the eruption of Tambora.

Geologic evidence indicates that Yellowstone last erupted six hundred thousand years ago and archaeological and anthropological evidence hints towards the last eruption nearly driving the human race to extinction. Geologists have determined that this super volcano has, on average, erupted every six hundred thousand years. While there is no immediate evidence of an eruption occurring anytime soon there is nothing to guarantee that it couldn’t happen tomorrow.

The direct impact of such an eruption would result in millions of human deaths in the surrounding areas. The evidence is that past eruptions have wiped out all life within a couple hundred kilometers of the event. Today this would include the cities of Billings, MT and Idaho Falls, ID. Depending on the direction of the winds at the time Boise, ID, Casper, WY or Sheridan, WY would be destroyed as well. This destruction would mean the complete elimination of all life within that area.

Such an eruption would result in climate change of the likes of which those obsessed with global warming could never imagine. At the very least the Earth would experience several years of far below average temperatures. The eruption of Tambora resulted in an estimated drop of average global temperatures of 5 degrees over the next year. The likely result of an eruption of Yellowstone would be a drop of tens of degrees over several years. Mass starvation due to crop failures would probably be the minimum consequence of such an event.

Even worse, however, would be the longer term climate changes that would result from such an eruption. It has been theorized that just such eruptions have influenced the advance of glaciers into the temperate regions of the world. An eruption of a super volcano could result in the return of ice covering virtually all of Canada, Europe and Northern Asia, for thousands of years. If that were to occur, life as we know it would be restricted to a narrow band in the tropics, land that is currently predominately rainforest and desert.

Why has such an event been largely ignored by those that are always shouting about the dangers we face? Most likely because, if it were to occur, there would be absolutely nothing we could do to prevent it, or even to prepare for it. It is believed that global warming caused by man’s activities can be ameliorated by restricting those activities. And, we just might have the technology to prevent an asteroid impact given enough warning. The eruption of a super volcano would be a completely different situation. It would be the ultimate disaster scenario and one that it may be easier not to think about.