Case Study - Mount St Helens

Mount St. Helens is in the Washington state, USA. It's the cascade range on the mountains. The whole effects started are in the table below.

20th March 1980 - There was an earthquake under the mountain caused by magma beginning to move.
25th March - 47 earthquakes occur
26th March - Because of this, warnings were issued to locals saying they may need to evacuate.
27th March - Gas and steam came out of the top of the mountain
3rd April - A bulge started to appear on the side of the mountain.
30th April - Scientists issued another warning and authorities put a 30km danger zone around the volcano.
10th May - There were several earthquakes under the mountain. The bulge grew around 1.5m a day.
18th May - The volcano erupted.

Some instant effects were

- The mountain had shrunk by 365m
- It flattened and burnt trees over 360 squared kilometers
- 12 million salmon were killed
- The smoke, dust and ash went up and made a cloud 24km in the sky.
- The cost of the damage by the ash alone was £8.5 million
- 61 people died, mainly scientists and photographers
- The flow was 30km/hour

Short term effects

- 61 died
- Flattened and burnt trees over 360 squared kilometers
- Planes diverted

Long term effects

- US government gave $951 to help rebuild the place
- The area is now a tourist attraction, making it more wealthy.
- Increased risk of flooding