Causes and effects of Montserrat volcanic eruption
- Created by: Lina
- Created on: 12-04-14 16:49
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- Montserrat Eruption
- Effects
- Some parts of the island suffered blackout conditions- the sun was obstructed by the ash cloud
- The ash cooled-> fell back on to some parts of the island
- Ash deposits- 2-3 mm thick
- A total of 4 km2 was covered by deposits
- Ash deposits- 2-3 mm thick
- The eruption of the volcano shouldn't have had a major impact on people
- The affected areas were in the Exclusion Zone set up after an eruption in 1995
- 25 June, 1997- authorised people were in the zone to carry out essential tasks+ monitor the volcanic activity.
- An eruption looked likely-> the workers evacuated safely by responsing to the emergency sirens
- Unauthorised people in the Exclusion Zone were too far away to hear the sirens
- Thought they would receive audible warning from the volcano as it was going to erupt-> didn't happen-> were caught unawares
- Unauthorised people in the Exclusion Zone were too far away to hear the sirens
- An eruption looked likely-> the workers evacuated safely by responsing to the emergency sirens
- 25 June, 1997- authorised people were in the zone to carry out essential tasks+ monitor the volcanic activity.
- The affected areas were in the Exclusion Zone set up after an eruption in 1995
- 7 people killed by the surge in Streatham+ Windy Hill area
- Villages affected by deposits:
- Dyer
- Farrell's Yard
- Windy Hill
- Streatham
- Harris
- Farm and Trant
- Houses in the Exclusion Zone- destroyed by the impact of rock, up to 5m in size
- Should have been empty
- 15 people were living there
- Mostly farmers, who produced crops to feed evacuees
- 15 people were living there
- Should have been empty
- Causes
- Destructive plate boundary- towards
- The North American Plate subducted under the Carribean plate
- Oceanic North American plate- denser than the Carribean continental plate
- Convection currents pulled NA plate into the mantle
- Heat+ friction-> the rock melted
- Lighter than the surrounding rock
- Rose through cracks towards the Earth's surface
- Formed the volcanic island
- Produced thick sticky lava
- Andesite
- The lava builded up at the top of the volcano in a dome
- Too heavy-> collapsed
- A huge ash cloud formed
- Rose rapidly
- A height of 10km
- Strong winds blew the clouds of ash westwards over the island
- Rose rapidly
- Hot rocks, ash+ gas ejected from the volcano
- Pyroclastic flows
- Fast moving
- Destroy everything in their path
- Killed 19 people
- Spread out+ flattened treed on the ridge surrounding
- Farrell's Yard
- No vegetation left, just bare vegetable beds+ the soil was baked hard
- Farrell's Yard
- Pyroclastic flows
- A huge ash cloud formed
- Too heavy-> collapsed
- Produced thick sticky lava
- Formed the volcanic island
- Rose through cracks towards the Earth's surface
- Lighter than the surrounding rock
- Heat+ friction-> the rock melted
- 25 June, 1997
- Chances Peak Volcano
- Produced thick sticky lava
- Andesite
- The lava builded up at the top of the volcano in a dome
- Too heavy-> collapsed
- A huge ash cloud formed
- Rose rapidly
- A height of 10km
- Strong winds blew the clouds of ash westwards over the island
- Rose rapidly
- Hot rocks, ash+ gas ejected from the volcano
- Pyroclastic flows
- Fast moving
- Destroy everything in their path
- Killed 19 people
- Spread out+ flattened treed on the ridge surrounding
- Farrell's Yard
- No vegetation left, just bare vegetable beds+ the soil was baked hard
- Farrell's Yard
- Pyroclastic flows
- A huge ash cloud formed
- Too heavy-> collapsed
- Produced thick sticky lava
- Chances Peak Volcano
- Effects
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