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Howcome Volcanoes?

  1. Jan 27, 2006 #1
    Howcome VOlcanoes don't destroy more stuff? I've noticed that volcanoes can be tens of thousands of times more powerful than the nuke on Hiroshima ,take Mt.St.Helens. Helens was close to 27,000 times more powerful that that bomb dropped but didn't do nearly as much damage. A 20 megaton nuke can be felt up to 40 miles away but from the looks of it The Mt.St.Eruption didn't go out more than 3 miles or so. With that kind of power I'd expect a huge crate about 7 miles from center to edge. But all that happen was the trees in the surrounded forest got leveled, the wildlife burned and around 60 people died. I know not alot of people were not around the immediate vacinity but that's not alot of casualties. With many many thousands of megatons in kinetic power I'd think that the person whom took those pictures while it was erupting would have just fried to death. I don't know that it was a person now but a camera shouldn't stand that force.

    And then there's Mt.Penatubo......Mt.St.Helens big grandpa..........could knock a whole island off the map.
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  3. Jan 27, 2006 #2


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    (Krakatoa, when it get go last century, blew the top third of the mountain off. The sound was heard 4000 miles away and the shock wave travelled around the Earth twice. It is the largest eruption in recorded history.)

    But volcanic eruptions aren't like nuclear bombs. Unlike bombs, don't vent their force upon the ground, they vent it into the atmosphere. Unlike nuclear bombs they don't happen 570 metres from densely populated areas. They're just not designed to destroy.
  4. Jan 28, 2006 #3


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    Dearly Missed

    Of course, another reason why volcanoes don't tend to do a lot of damage on the human population is that most humans would be reluctant to settle down in the vicinity of a smoking and fire-belching mountain..:rolleyes:
  5. Jan 28, 2006 #4


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    I have flown right over the top of what's left of Mt. St. Helens (when I was stationed in Washington). If you were to see for yourself the size and depth of the chunk that is now missing, you would be asking how anyone near could survive it. Then again, you could also ask the people of Pompei...
  6. Jan 28, 2006 #5


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    If you saw the craters produced by the underground nuclear tests in Nevada you would recognize that, as large as they are, they pale in comparison with volcanic craters such as Mt. St. Helens or Krakatoa.
  7. Jan 28, 2006 #6


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    From here I think you way understate the damage done
  8. Jan 28, 2006 #7
    Wouldn't it be cool if we could somehow harness the power of a volcano?
    27 thousand times the energyof Hiroshima could power a nice sized town for a considerablee amount of time. ALway wondered why we don't harness the destructive power of the Earth.....that and lightning.
  9. Jan 28, 2006 #8


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    Keep in mind that the energy release in a nuclear explosion occurs on a μs to ms time scale, and that the volcanic "explosion" is generally going on over hours.
  10. Jan 29, 2006 #9


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    There are two main reasons we don't normally try to harnass the power of natural disasters.
    1- How to collect the energy. I don't know about you, but I'm pretty stumped on how to convert an explosive eruption into electricity. Similarly, it would be more trouble than its worth to make a turbine strong enough to survive and operate during a hurrican or tornado.

    2- The more powerful the event, the rarer they are. With most phenomena like this, the big events put out a lot of energy, but the sum of all the smaller and more frequent events put out more in the long run. I've often heard hurricanes expressed in x hiroshimas of energy too, but if a hurricane has a return period of say 20-30 years in a certain area, in the long haul it is much more worthwhile to build smaller turbines to collect the normal winds in the time in between the storms.
  11. Jan 29, 2006 #10
    Well take a volcano. We could put some kind of pressure converter in it while the intense pressure is building electric current is being generated.

    And then there's lightning.....somethat occurs often. If we could have some lightning rods out in a field or allong the highways that would produce alotof energy. Even if there's not a storm,there's alway lighting somwhere.
  12. Jan 31, 2006 #11
    There was a news camera guy right at Mt.St.Helen's when she blew. He was from KIRO NEWS Seattle. He thought he was going to die but he kept on commentating and shooting footage.

    He caught the moment when the actual mountain was blown wide open by the heartiest of blasts the mountain produced during its eruption.

    At first it was a calm day and he's out there investigating the geological reports of the possibility of an eruption. He was about 5 miles from the crater itself.

    Then it blew and he was thrown around, soon to be in shock. The sky started getting black with this growing black cloud of smoke and debris coming from St.Helens, his vid.camera capturing the advancing menace of darkness. He was on the side of the volcano where the liquifaction of the soil and sand and loose rocks began to move down the mountainside. On the other side is where the devistation is today evident to the trees... for miles and miles around... blown over by the blast.

    This guy is so in shock by now that he's talking about his car... he wonders why its not there... or is he lost... he's wandering and kind of praying for his life at the same time.

    Then he gets a shot of his car being carried away in a river of mud moving at about 60 miles per hour... down the mountain some more.

    And all I heard of the whole eruption was what sounded like someone's chimney exploding... across the street... since it was saturday @ 9:00am after a friday night out.:uhh:

    PS. The news guy actually got out ok. He had been broadcasting live so they had a fix on him. I'd like to recommend him for a geology reporting medal of honour or something.
  13. Feb 5, 2006 #12


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    The problem is the POWER - too much energy in too short a period of time.

    It would useful to harness the "energy", i.e. geothermal energy, at a much slower rate. This being done in some areas, e.g. Iceland, NZ, and parts of the US, and others.
  14. Feb 16, 2006 #13
    volcanoes are of different kinds. the ordinary volcanoes at the edge of oceanic plates and the shield volcanoes. can you tell me what are shield volcanoes and why do they occur? they seem to have had an effect on life- the Deccan shield and the Siberian shield eruptions were contemporary to two major mass extinction events. also what role did volcanoes play in gradual accretion of continents during earth's history.
  15. Feb 17, 2006 #14
  16. Feb 17, 2006 #15
    I found this while searching for information about the volcanic eruption from between 400 - 600 ad... thought to be the first Krakatoa eruption before it blew again in the 1800s.


    This article suggests that global warming would be much further along today if it wasn't for this eruption.

    The first eruption was of a much more massive scale and dumped earth in to a nuclear winter for a number of years... as is seen in tree rings and from litrature from the "dark ages". Reports of crop failure and other unearthly occurances abound from that period including the Black Plague. This illustrates the effects that major eruptions could have on the climate and life on earth.

    From: http://volcano.und.nodak.edu/vwdocs/current_volcs/krakatau/krakatau.html [Broken]
    Last edited by a moderator: May 2, 2017
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