Earth Science Yellowstone's Super Sisters - A look at other calderas

Discussion in 'Earth Science' started by Bleys, Mar 17, 2005.

  1. Bleys

    Bleys Phoenix Takes Flight Staff Member

    Yellowstone\'s Super Sisters - A look at other calderas

    Interesting read from Quayle's site taken from the







    This is just a sampling of what is currently out there being studied, but there are also calderas that no one knows much about. For example: Ethiopia's 460-square-mile Awasa caldera and the 1,000-square-mile Pastos Grandes caldera of Bolivia. The Bolivian caldera rivals Toba if you can believe it.

  2. mscbkc070904

    mscbkc070904 Premium Member

    Very interesting read Bleys. What is the explosion equivalent in realtive terms when it says 50x Mt St Helens? I remember reading that one Mt St Helens explosion was equivalent to like 10 nukes or 50 atom bombs, something of that nature. The reason I ask this is some people, not from the US are not sure what Mt St Helens explosion is like, so the relevancy is sort of hard to imagine.
  3. mscbkc070904

    mscbkc070904 Premium Member

    Oh and yeah define a caldera, what is that exactly, like a concave land mass or formation of lava dried up or ash sediment?
  4. Bleys

    Bleys Phoenix Takes Flight Staff Member

    What exactly is a caldera or a super volcano?

    A large, basin-shaped volcanic depression that is more or less circular in form. Most volcanic calderas are produced by collapse of the roof of a magma chamber due to removal of magma by voluminous eruptions or subterranean withdrawal of the magma, although some calderas may be formed by explosive removal of the upper part of a volcano.

    edit to include link to usgs site with photos of various calderas - Link
  5. mscbkc070904

    mscbkc070904 Premium Member

    Oh OK, got it, the caldera is the top of hte volcanoe after it blows, I was thinking it was down below or where a volcanoe has exploded at lower elevations, like out the side, due to compression expansion, like a vent and the result was a caldera. Thanks.
  6. mscbkc070904

    mscbkc070904 Premium Member

    What are the different types of volcanoes? Heard of one called a stratovolcanoe, does that mean its bigger, or do they go by size or age IOW, how do you classify one?
  7. Bleys

    Bleys Phoenix Takes Flight Staff Member

    From another really good site

    Several classifications:

    Rhyolite Caldera Complexes

    Shield Volcanoes

    Strato Volcanoes

    Flood Basalts

    Monogenetic Fields

    Mid-ocean ridges
    More on each type can be found - here