mt st helens Flashcards
where is it?
washington state
when did it happen?
18th may 1980n
what mountain range is it part of?
cascade
what is significant about it?
worst eruption in US history
what two plates was it caused by?
Juan de Fuca plate subducting beneath N america
when were minor earthquakes felt?
march 1980
what did scientists do
they predicted an earthquake due to the change in shape of volcano and earthwaues so an evacuation was done
why did not many people evacuated?
they did but because nothing happened for two months they moved back
what mistake did scientists make?
they did not predict that the volcano would erupt laterally
safe zones were in these areas
what % of people that died were outside the exclusion zones?
90%
how many people died?
57
how many animals died?
7000
how far did damage to plants and animals extent?
any animals within 25km north died
how many homes destroyed?
250
how many bridges destroyed?
47
how much ash fell?
15 cm
why was it economically devastating?
it destroyed the timber industry
how much did damage cost?
1.1 billion
what was the damage to crops?
$100 million
what was the short term responses?
national guard flown in to save people using helicopters saved 198 people
gas masks given
how many gas masks were given
2 million
how much was given to farmers as compensation?
70 million
why were new tourist facilities made?
as tourists stopped coming as thought they were in danger
what happened to bridges as LTR/
they were widened and made stronger
who is it now monitored by?
USGS
how long did the removal of ash take?
10 weeks
