Mount St. Helens

Question 1

What happened when St. Helens erupted on 18th May 1980?

Answer 1

North face of the volcano collapsed
It was a lateral (sideways) eruption
Very violent
Triggered by a minor earthquake
30km blast zone to the north + west of the volcano

Question 2

Short term responses to the eruption

Answer 2

Red/blue exclusion zones set up (red zone for state troopers and USGS scientists only) (blue zone for local authorities (police) and loggers)
Evacuation within a 11km radius
St. Helens was constantly monitored for signs of eruption
Coordination centre set up in Vancouver, Canada

Question 3

Long term responses to the eruption

Answer 3

People became more cautious about volcanic eruptions
Became one of the most studied volcanoes worldwide
David Johnston Memorial Observatory was set up
St. Helens was studied by volcanologists

Question 4

Primary effects of the eruption

Answer 4

57 people killed
Forestry and tourist industries destroyed
230km blast zone
Spirit Lake was buried by a mud flow
Ash fell on nearby cities such as Portland

Question 5

Secondary effects of the eruption

Answer 5

People were treated for burns
Long term respiratory problems (asthma and bronchitis)
Jobs lost
Tourists visited to see the damage (dark tourism)
Ash was mixed into soil (soil became fertile)
Trees and landscape destroyed

Question 6

What were the warning signs of the 1980 eruption?

Answer 6

Smoke and ash
Newly formed crater
Magmatic activity
Sulphuric gas