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					            VoLcAnO’s

            Hello, my name is Jo
This presentation is to see how volcano’s are
structured and the understanding of eruptions
     and environments around volcano’s.
White Island

       The map opposite shows an
        island near New Zealand called
        White Island. No body lives
        there even though it is
        beautiful this is because it has
        its very own volcano. This
        volcano is one of New
        Zealand's most active
        volcanoes. It has killed many
        people that worked there doing
        jobs such as men at sulphur
        works. It caused a landslide.
    White Island’s Volcano active!


This is the earths structure
–


There is a thin layer of
crust, this is just below us.
The mantle contains maga
and is extremely hot and
has a thickness of 2900
kilometres.


The core has two parts, the
inner and outer core. The
heat is hotter than the
anywhere else in the inner
core and the outer core is
only a little less.
                Volcanoes
 Volcanoes are caused by tectonic plates,
  that have moved as the millions of years
  have gone by. Thousands of years ago the
  earth would not have looked like it does
  now, this is the cause of the plates moving
  which can separate countries as results of
  volcanoes and earthquakes.

                               Mount St Helens
                                 history -

 Shaken by an earthquake measuring 5.1 on the Richter
  scale, the north face of this tall symmetrical mountain
  collapsed in a massive rock debris avalanche. Nearly 230
  square miles of forest was blown over or left dead and
  standing. At the same time a mushroom-shaped column of
  ash rose thousands of feet skyward and drifted downwind,
  turning day into night as dark, grey ash fell over eastern
  Washington and beyond. The eruption lasted 9 hours, but
  Mount St. Helens and the surrounding landscape were
  dramatically changed within moments.
    Eyewitness account of mount St
   Helens eruption on May 18th 1980
 Many individuals who were in the vicinity of Mount St. Helens on May 18 were
  interviewed to gain information on phenomena associated with the eruption. The
  observed phenomena include an earthquake, a massive avalanche of the volcano's
  north flank, a directed blast, development of the vertical eruption, a mudflow in the
  South Fork Tousle River valley, and the fall of early eruptive products.
 "As the avalanche reached the halfway point on the mountain, the summit
   eruption began with a dense black cloud followed by lighter grey material. A
   second eruption halfway down the slope occurred moments later * * *." At this
   time the avalanche appeared to consist of upper and lower parts. The flank
   eruption was between the two. Seconds later the upper slide overrode the flank
   eruption and material was hurled far down slope onto the lower slide. About 45
   s after the landslide began, the eruptive centres merged and the rapidly
   expanding cloud overtook the avalanche.”
What happened on the 18th of May

This is what Mount St Helens looked like
 before May the 18th. I will now show you the
 picture of the volcano and the changes that
 was made to it!
                   May 18th
 One side of the volcano collapsed in a landslide
  and the eruption was mainly pyroclastic flow.
  These are effect of the pyroclastic flow.
 Diagram of Mount St Helens
This is a diagram of
Mount St Helens
 Thank you you for listening to my proect on
  volcanos I hope you have learned a little ore
  abou them and understand the eruptions
  more too.

				
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