Earth Science Megaplumes

Discussion in 'Earth Science' started by Zsandmann, Oct 19, 2004.

  1. Zsandmann

    Zsandmann Premium Member

    A little know oceanic feature is the megaplume. I learned about them first in Dan Brown's Deception Point and wanted to know more. Sometimes the crust under the ocean can thin, for what ever reason. Ocean crust is basaltic in composition and much thinner than terrestrial crust. When a thnning happens a magma plume may form underneath creating a hot spot on the ocean floor.

    This plume will heat up the ocean crust and the sediments above until it begins to heat the ocean water in contact with the floor. When ocean water heats it becomes less dense than the deep cold ocean water and rises. Cold ocean water rushes in to fill the void. This begins an upwelling of water from deep and a sinking of surface water. A convection cell is created.

    This convection cell is in fact a large whirlpool, vortex, or what-have-you. They can last for a very long time. Most often they go unnoticed unless some wayward ship or remote device is surked in. They are not usually that strong though.

    In a normal megaplume the ocean water is continuosly cooling the magmabody until it crystalizes, but in rare occasions the dome may rupture creating a waterspout. This occurs when the magma contacts ocean water instantly vaporizing the water. The steam rises, expanding as it depressurizes, until it reaches the surface. A resulting vortex could easily submerge a ship without any warning. The sea would in fact just drop out from underneath.

    This is a probable cause for some of the disappearances of ships in the Burmuda Triangle. No little green men needed. There are records of megaplumes in the equatorial Atlantic.

    For more info try these links:
    http://oceanexplorer.noaa.gov/explorations/02fire/background/education/media/ring_mystery_9_12.pdf
    http://www.pmel.noaa.gov/pubs/outstand/bake1050/figs.shtml
     
  2. oddtodd

    oddtodd Premium Member

    That's cool !! I also like the chunks of methane that can float to the surface and go boom .... It would be strange if the ocean turned into a natural mine field with occasional sink holes ...

    <ZS> You mean gas hydrates. Im planning a post on that also.
     
  3. bodebliss

    bodebliss The Zoc-La of Kromm-B Premium Member

    They don't know the full extent of gas hydrate deposits around the world, but they believe the total might be 100 times the oil and natural reserves
     
  4. junior_smith

    junior_smith Premium Member

    The second I saw the word megaplume I thought of Dan Brown's book as well.

    By far though the most interesting oceanic feature is Blue Hole discovered by Jaque Cousteau, I will probably do a new thread on it, lol.

    Edit: mizar - spelling
     
  5. bodebliss

    bodebliss The Zoc-La of Kromm-B Premium Member

    junior,

    You mean the places in the crust where the plates pull apart , but no magma wells up and fills gap.
     
  6. mscbkc070904

    mscbkc070904 Premium Member

    I watched a show back some time ago on the Bermuda triangle about gas that pretruded the ocean floor and rose into the air. They tested this with the old WWII planes that kept disappearing along with ships, saying the gas is so strong at times that it can kill the engine of a plane (not so much now) and powerful enough to sink a ship at the snap of a finger.

    It had to do with the ocean floor opening little holes, possibly megaplumes forming in a prerequisite stage.

    Thanks for the info, exciting to read about.
     
  7. Zsandmann

    Zsandmann Premium Member

    you are refurring to gas hydrates.
    I think I made a post a while back about those.
    i saw the program also, it was very good.
     
  8. mscbkc070904

    mscbkc070904 Premium Member

    Yes gas hydrates forming from the ocean floor. There was several actual documentaries on that, one on the Bermude Triangle, the other on the WWII aircraft and one on lost ships of the triangle.