Volcano Case Study: Mt St Helens Flashcards
There were no warnings that a major eruption would eventually happen. (T/F)
False
From _____ ____ onwards there had been ____ ________ which were recorded and monitored using ____________. These increased in _____ and _________ which indicated that the volcano was preparing to _____.
March, 1980, minor, earthquakes, seismographs, size, frequency, erupt
What method was used to predict danger zones?
Hazard mapping
What is hazard mapping?
Using past eruptions of the volcano to identify which areas would be a part of the “danger zone” and therefore need to be evacuated.
As a measure taken before the volcano erupted, an emergency response plan was made, this included… [3]
[1]Emergency helicopters & planes on hand
[2] Roads were closed
[3] Reservoirs drained
Experts did not predict the eruption blast would occur on the north side of the volcano, this meant that…
Exclusion zones were set up in the wrong place, leading to people dying in areas outside the exclusion zone in what they were lead to believe were safe areas.
What were some immediate responses to the eruption? [3]
[1] Rescuing stranded people
[2] Providing shelter for the newly homeless
[3] Giving medical attention
How many people were rescued in the immediate rescue operation?
198
After the eruption, the landscape changed so much that…
The maps were no longer accurate, this slowed down rescue efforts.
What were some primary impacts of the eruption? [3]
[1] Farms destroyed due to being covered in ash
[2] 200 homes were destroyed
[3] 57 People died - most from outside of the evacuated zones
What were some secondary impacts of the eruption? [3]
[1] Columbia River shipping channel was closed, costing $3 million per month in lost trade
[2] Water produced from melting ice & snow on the top of the volcano created mudflows which choked rivers & killed waterlife
[3] Tourists no longer visited the area causing a reduction in the local economy
What were some long term responses to the eruption? [3]
[1] New tourist facilities built to bring visitors back into the area
[2] Money given to rebuild houses, compensate farmers & redevelop salmon hatcheries after 12 million young salmon were killed
[3] Millions of trees replanted due to the huge loss of timber
When did Mt St Helens erupt?
March 27, 1980 the eruptions began, the most explosive of which occurred May 18
