What is a super volcano?

Question

What distinguishes a super volcano from a regular one? Is it mainly the size of the eruption that the volcano has the potential to have?

Answer 1

There was a TV show on this topic just last night, very interesting. A regular volcano is a mountain, it is lava and ash piled up from eruptions over the years. A super volcano is a depression in the ground. The magma chamber does not vent for a long period of time so it gets an enormous amount of magma under an enormous amount of pressure and when it vents it is inevitably a very large eruption, the material is blasted far away so very little accumulates to form a mountain. The earth above the magma chamber commonly collapses into the chamber once the chamber has vented--thus the pit. The last super eruption was thought to be Toba, which is now a lake in Indonesia, about 74,000 years ago, and which came very close to exterminating the human race. Yellowstone is considered a super volcano, as well and has erupted 3 times in the last 2+ million years, the last estimated about 700,000 years ago. You can google Toba, it looks like a fairly ordinary lake. Appearances can be deceptive.

Answer 2

Super volcanoes are generally caldera volcanoes rather than cones. They are covered by lakes, which makes them deceptive. People play on the waters unaware of the potential for destruction there. The two which come to mind are Mount Whitney in California and Yellowstone Park. These volcanoes have erupted with a huge blast out of the ground and have spewed a huge amount of material into the atmosphere equal to many times an eruption of, say, Mount St. Helen's.

I thought I could easily find a site on volcanoes. Even Wikipedia has a lame site!
I cannot find on-line sites telling about the climate changing eruption of the above volcanoes. I remember the discussion of them in a college geology class.

Answer 3

It is the sheer size that denotes a super volcano. They are many, many times the size of Mt St Helens!!!

They must eject a minimum of 1000 cu km just to be called one!

Geologists in the US have found evidence suggesting volcanic activity in Yellowstone National Park will eventually lead to a colossal eruption. Half the US will be covered in ash up to 3 feet (1 meter) deep.

About 74,000 years ago, in what is now Sumatra, a volcano called Toba blew with a force estimated at 10,000 times that of Mount St. Helens. Ash darkened the sky all around the planet. This is thought to be the largest of the known super volcanoes.

Based on the latest evidence, eruptions the size of the giant Yellowstone and Toba events occur at least every 100,000 years, Sparks said, "and it could be as high as every 50,000 years. There are smaller but nevertheless huge eruptions which would have continental to global consequences every 5,000 years or so."

Yellowstone eruptions -

2.2 million years ago 2500 cubic kilometres
1.2 million years ago 280 cubic kilometres
0.6 million years ago 1000 cubic kilometres

Answer 4

A really enormous volcano, Yellow Stone park has one. If that blows we are screwed.