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Mount St Helens

1/5 in cascade range Washington state USA

March 1980 signs of impending erruption

1st earthquake occurred then steam filled with ash exploded over the white glacier on top of the mountain

residents told to leave and there was a 8km exclusion zone around the creater

a composite volcano (steep sided volcano found on a destructive plate margin between the Juan de Fuca plate and teh north american plate

DATE : 8:32am 18 May

eruption occurred and there was an earthquake of 5.1 on the Richter Scale that triggered a landslide

Short term effects

on man

on the natural world

loss of life

#deaths were reduced due to 8 km exclusion zone

57 people killed - mostly due to the release of poisonous gasses from the eruption

some were killed to due to the force and due to mudflow

few settlement in the area but several logging camps were destroyed

floodwater from snow melt an infilled lakes etc. washed away roads and bridges.so transport links disrupted. falling ash blocked roads and caused probles

crops and livestock lost on valley floors due to the flooding. causing financial lost for farmers in the area.settling dust ruined 12% of the total crops

services were disrupted.electrical supplies were interrupted and telephone wires cut.

forestry and fishing industries affected. 250 km sq. of forest total destroyed by the blast leading to loss of revenue for the logging industry. a fishery with a hatchery for trout and salmon was destroyed alone 250 km of rivers which

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