Top of Volcano Blown Off In Blast! 18/04/82
60 people were killed today when Mt. St Helens blew its top
Mt. St Helens erupted two years ago today in a blast that caused the volcano to be
reduced by 451 metres (1313 feet). The volcano is south-western Washington and is part of
the Cascade Range.
Mt. St Helens had been dormant since 1859 and has let off its first blast since then
today. The volcano killed all life in an area of 180 sq. cm(70 sq. miles) including at
least 60 people! The ash and dust spread much farther than this, of course. Today it is
continuing to emit to emit dust and ash at intervals. Today a monument has been erected
called the National Volcano Monument, in memory of this tragedy.
How A Volcano is Formed
A volcano is formed in this way:
1)Magma starts off below the crust.
2)Magma collects in chamber.
3) Pressure rises.
4) The pressure rises so high that the magma breaks through the crust and volcano
erupts.
Often volcanoes are cone shaped. You might ask: "How do they get like that?"
This is the answer:
When a volcano erupts many minerals and fragments are blown up, many falling in a circle
around the volcano. As lava flows onto this it builds up around the volcano, so the
volcano gets higher still. Each time the volcano erupts, more lava, minerals and
fragments are emitted. Therefore every time a volcano erupts it erupts it gets taller,
and some like Mt. St. Helens have even become tall enough to be classed a mountain.
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