Super Volcanoes

Inspecting Rocks
I was reading about Supervolcanoes. This is just a term for really big volcanoes and was coined by the producers of the BBC program Horizon. And they mean so big that we do not recognise them as volcanos. When they erupt they do not form mountains of solid magma, but huge depressions where the land at the eruption site collapses. One of the largest super volcanoes in the world is in the US at the Yellowstone National Park. Geologists had observed that many of the rocks in the area were made of compacted ash, but they could find no extinct volcano or crater. It was only after NASA took some photos from the air of Yellowstone that the geologists were able to observe a massive caldera more than 2000 square kilometers wide. After analyzing the layers of ash, they determined that it had exploded 3 times in the last 2 million years. Each time was regularly spaced about 600,000 years apart. Just in case you are wondering, the last explosion was about 600,000 years ago. There are several other supervolcanoes in the world, notable among them Lake Toba in Sumatra and Kikai Caldera in Japan. What would happen if such a volcano exploded?

volcanoDisaster on a global scale. The supervolcano at Lake Toba exploded about 74,000 years ago and spewed out nearly 3,000 cubic kilometers of material, caused complete deforestation in South East Asia and triggered a volcanic winter that started an instant Ice Age. It also probably caused drastic population reduction worldwide. This explosive force would be about 10,000 times as violent as the Mt. St. Helens Eruption. If Yellowstone erupts it would probably cause death and destruction for hundreds of miles around it and also cover all of the United States with a layer of 2 meters of ash causing crops to vanish overnight. Who knows what the resulting volcanic winter will bring? but you can be sure that it will affect the whole world. It is really very humbling to realize how vulnerable mankind is to natural disasters.

2 Responses to “Super Volcanoes”

  1. hkaul Says:

    Good one Sameer.
    Although its old news ;-)

    Compare these to the scary Krakatoa eruption in 1883 -

    “The noise was heard over 4600 km away, throughout the Indian Ocean, from Rodriguez Island and Sri Lanka in the west, to Australia in the east …. generated mountainous tsunamis, up to 40 m tall …. Tephra from the eruption fell as far as 2,500 km downwind in the days following the eruption …. the finest fragments were propelled high into the stratosphere, spreading outward as a broad cloud across the entire equatorial belt in only two weeks. These particles would remain suspended in the atmosphere for years, propogating farther to the north and south before finally dissipating …. reflected enough sunlight to cause global temperatures to drop by several degrees. This aerosol-rich veil also generated spectacular optical effects over 70% of the earth’s surface. ”

    http://www.geology.sdsu.edu/how_volcanoes_work/Krakatau.html
    http://en.wikipedia.org/wiki/Krakatoa

    A supervolcano eruption would be hundreds of times stronger than this.

    p.s. Your link to “My Delicious” on the sidebar looks nice.

  2. Sameer Says:

    Yes, I know this is old news. The BBC program was made in the 20th century :) . However I just recently read about it, so I decided to blog it. I forgot about good old Krakatoa.

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