Flashcards in Mount St Helens Volcano Case Study Deck (22):
1
How many people were killed?
57
2
How many homes were destroyed?
250
3
What did it measure on the Richter scale?
5.1
4
What were three other short term effects?
Electricity and phone lines cut
Every tree with in 250km destroyed
Spirit lake filled
5
When did the small eruptions continue until?
1986
6
What did the cost of repairs reach?
$2.64 billion dollars
7
What are three other long term effects?
Loss of farming income as 12% of crops destroyed
Tourism badly effected
Access to area difficult
8
When did the eruption take place?
18th may 1980 in the state of Washington
9
When is mount st Helens located?
On a destructive plate boundary where the Juan de Fuca and North American plate meet
10
Why did the eruption happen?
Plate movement due to convection currents in the mantle = plates collide =sub-ducting of denser plate =magma rise and pressure builds
11
What were the short term responses?
Search and rescue of survivors by helicopter
Emergency medical treatment
Masks provided to filter dust
Roads cleared of ash
Shelters found for stranded tourists and the homeless
12
What were the long term responses?
Rebuild homes buildings and roads
Attract tourists back to area by building new tourist attractions to improve economy
Clear drainage channels to prevent flooding
Removal of fallen trees
13
Was the area prepared beforehand?
5km exclusion zone was in place as well as evacuation
No fly zone
14
How deep was the Ash in certain places?
1M deep
15
Which animals suffered from the loss of vegetation?
Dear elk bear
16
What three other things were destroyed?
Salmon hatchery
Logging camps
Bridges
17
Why did the mudslide take place?
Lava mixed with ice and snow from mountains caused slide
18
What type of volcano is Mount St. Helens?
Composite
19
What are the physical affects?
Rivers were flooded and silted for up to 24km
400 square km of forests were flattened
20
What happened to the river Columbia?
It was dredged to remove logs and levees were built to reduce
Floods
21
Who was compensated as a long term response?
Farmers because their produce was destroyed
22