Thursday, October 18, 2012

Top of Volcano Blown of in Blast!

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.

NB: This article originally contained pictures, elongating it and making it better presented.

(c)Aron Cohen,1991

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