Zusammenfassung der Ressource
Volcanic Case Study
Mount St Helens
- Causes of the Eruption
- An eruption is caused by plates moving
- Volcanoes are formed at either constructive or destructive plate boundaries
- Convection currents in the
magma cause the plates to move
- Primary and secondary effects
- Primary- death
- Secondary death
- Primary- destroys wildlife
- Primary- Fires
- Primary- Evacuation
- Primary- Building ruined
- Secondary- Part of the area
becomes 'out of bounds'
- Secondary- lack of food and water
- Positive and Negative impacts
- Positive- increased fertility in soil
- Negative- destroys wildlife
- Positive- becomes a better-known
area. Increases tourism (long term)
- Negative- destroys houses and buildings
- Negative- kills people both directly (hit by
rocks) and indirectly (contaminates water)
- Negative- costs a lot of money to recover
- Positive- other countries come together to
help that country
- Immediate and Long-Term responses
- immediate response- sending out helicopters
to search for those who need help
- Immediate response-emergency treatmemt
- Immediate response- finding shelter for
survivors who houses had become inhabitable
- Immediate response- clearing the ash
- Long term response- re-building
houses and buildings
- Long term responses- re-planting forests
- Long term response- re-build roads to bring back tourism
- Monitoring and Predicting erruptions
- Earthquakes are a frequent sign of
an impending eruption
- Their frequency and strength
can be recorded
- Tiltmeters can identify small subtle
changes in the landscape
- GPS is used to
identify changes as
little as 1mm
- Digital cameras on the crater's edge
can photograph any changes
- Gases are emitted before an
eruption which contains a large
amount of sulphur dioxide