Volcanoes Flashcards
What did the explosive nature of the Montserrat volcano cause?
30% of volcano destroyed due to the high silica levels at a destructive boundary
What is the location of Montserrat?
It is in North America, specifically the Carribean and is 10km wide and 16km long
- Montserrat
When the Carribean plate (continental) moved towards the Atlantic plate (oceanic), the Atlantic plate subducts due to convection currents
- Monserrat
Friction and magma builds up underneath a fissure in the earth’s crust at the convergent (destructive) plate
- Montserrat
As the viscious magma rises through the fissure, it creates a volcano therefore the island is made up of cooled lava
- Montserrat
The volcanoes found here are explosive due to the high silica levels
What happened to the population of Montserrat?
It fell by over 75% due to the risk - many people have permanently left
How many fatalities and injuries occured in Montserrat?
19 deaths, 7 injuries
What were some primary effects of the Montserrat eruption?
- Large areas including Plymouth, the capital, were destroyed by 12m of ash and mud
- Over 20 villages and 2/3 of buildings were destroyed
- Vegetation was destroyed by ash
- Schools and hospitals were destroyed
What are some secondary effects of the Montserrat eruption?
- Volcanic ash has improved soil fertility; yields have increased
- Many people suffer from silicosis, a respiratory disease, caused by volcanic ash
- GDP is 15% less than it was in 1997
- Damaged resorts led to a loss of income and reputation
- National Geographic rated it “Top new trip of 2010”
What is a hazard?
Something that has a potential to cause harm to people, environment or economies
Why are lava explosions found in destructive volcanoes?
Due to their high silica level
How are pyroclastic flows caused?
When magma pushes up a volcano very slowly and solidifies into lava fragments, which causes lava domes that crack and fall down the mountain
How is volcanic ash a hazard?
The blast out of the lava dome breaks up fragments of lava and lifts them high into the atmosphere which can cause damage to buildings, crops and can start fires
What has happened to the lava dome?
It has grown significantly
