Mount St Helens Assessment

Question 1

List some background information of the eruption

Answer 1

• volcano is in Southwestern Washington State, Portland
• May 18th 1980
• 8:32am

Question 2

List 3 causes of the eruption

Answer 2

• a large bulge appeared on the side of the mountain. This was because the main vent was blocked and so the magma had to go through the second vent leading to a large visible build up of magma.
• a magnitude 5 earthquake triggered the eruption and a massive landslide on the North face
• the mountain was on a destructive plate boundary (the oceanic Juan de Fuca and the continental North American).

Question 3

list 3 economic effects

Answer 3

economic:

• damage to crops costed $175 million
• communication routes were threatened e.g. railways
• $860 million-$1.1 billion damage worth in total

Question 4

list 3 environmental effects

Answer 4

environmental:

• 2 million birds, animals and fish were killed
• mudflows blocked and diverted rivers
• 230 square miles of forest was destroyed
• superheated gas was shot 12 miles into the air

Question 5

list 3 social effects

Answer 5

social:
- a medical unit was set up at a nearby school
- 60 people dead
- 72 missing

Question 6

list short term responses

Answer 6

short term:

• red zone was set up 3-8 miles across area
• people were evacuated
• a spotter plane was sent out to look for survivors and see the extent of the damage

Question 7

list long term responses

Answer 7

long term:

• 5 million trees were planted over 3 years
• a new highway was built
• a foundation was set up
• there was a large increase in tourism for the area