SCIENCE: Supervolcanoes

[M. Wolfe]

I found myself helping a friends younger brother with a school science project about Supervolcanoes and learnt some very interesting things. Thought I might share. :tongue:

Some of you will be aware of Yellowstone's Volcanism and that Yellowstone National Park is set on a Caldera making it a Supervolcano rating a VEI (Volcanic Explosivity Index (http://upload.wikimedia.org/wikipedia/commons/0/01/VEIfigure_en.svg)) 8, as big as they get. 8 is defined by an eruption event spewing 1000 cubic kilometres of ejecta or more. To put that in perspective the 1980 Mount st Helens (http://en.wikipedia.org/wiki/1980_Mount_St._Helens_eruption) eruption, hitting a 5 (http://upload.wikimedia.org/wikipedia/commons/2/21/MSH80_eruption_mount_st_helens_plume_05-18-80.jpg), had 180 cubic kilometres.
The Mount Vesuvius (http://en.wikipedia.org/wiki/Mount_Vesuvius#Eruption_of_AD_79) eruption of 79 which decimated Pompeii (http://upload.wikimedia.org/wikipedia/commons/5/5c/Pompeii_the_last_day_1.jpg) was also VEI 5 but with only 4 cubic kilometres of ejecta.

The greatest volcanic explosion was 27.8mya, La Garita Caldera (http://en.wikipedia.org/wiki/La_Garita_Caldera). This event spewed ~5000km^3.

By contrast, the most powerful human-made explosive device ever detonated, the Tsar Bomba or Emperor Bomb, had a yield of 50 megatons, whereas the eruption at La Garita was approximately 10^5 times more powerful. It is possibly the most energetic event on Earth since the Chicxulub impact, which was 50 times more powerful.http://en.wikipedia.org/wiki/La_Garita_Caldera#Size_of_Eruption

Closer to home, in the North Island of New Zealand we have our own Supervolcano named Lake Taupo. In 180 CE (http://en.wikipedia.org/wiki/Hatepe_eruption), Taupo erupted hitting 7 VEI with 120km^3 of ejecta. This event sent ash up into the atmosphere turning the sky over Rome and China red.
Going back further to 24,500 BCE (http://en.wikipedia.org/wiki/Oruanui_eruption) there was another eruption, this time VEI 8 with 1700km^3 of ejecta.

There are 10 Supervolcanoes (http://en.wikipedia.org/wiki/Category:VEI-8_volcanoes) around the globe.Scientists (http://www.springerlink.com/content/v17amvu0unn4v7v4/) predict that there is a 75% chance of a Supervolcano eruption in the next Million years but only a 1% chance of one in the next 450-7000 years.

It's interesting to consider the probable effects on humanity that one of these eruptions have. Specific effects would change depending of where abouts the eruption would occur but it would still affect the entire globe regardless. It's possible that it would invoke a small ice age for blocking out sunlight - how that would affect us, I have no idea.


So I dunno what you guys think or even care but I found this truly interesting.

[FalconAngel]

I saw a thing on that on the History Channel. Very interesting show. We have one of those super volcano under Old Faithful.

[lookin2tryit]

if the yellowstone area blows, the area within something like 500 miles is going to be radically affected.........theyve been watching it, and the dome has risen something like 8 inches in the last decade?

[M. Wolfe]

if the yellowstone area blows, the area within something like 500 miles is going to be radically affected.........theyve been watching it, and the dome has risen something like 8 inches in the last decade?

The whole whole would be significantly effected, the whole of the Americas would be severely effected but yes the 500 miles might probably be uninhabitable. The whole of Yellowstone will be wiped of the map.
I remember the news story that the Caldera was bulging and the lake was starting to run out at one end. Some tremors about the same time late last year..