Shapes of Volcano
- Created by: HannahColbs
- Created on: 26-04-16 08:31
View mindmap
- Shapes of Volcano
- Fissure Eruptions
- Occur when an elongated crack in the crust allows lava to spill out over a large area
- Location: rifts/early constructive (divergent) margins
- Example: Iceland
- Eurasian and North American plates are pulled apart
- Lava: Basaltic
- Eruptions: gentle, persistent
- Shield Volcanoes
- Lava: Basaltic
- Locations: Hot spots and where oceanic crust meets oceanic crust
- Eruptions: gentle, predictable
- Shape: gently sloping cones
- Example: Mauna Loa in Hawaii
- Stands 4,170m above sea level with a volume of 40,000km2
- Created by layers of less viscous lava
- Composite Volcanoes
- Lava: Andesitic
- Location: Destructive (convergent) margins
- Shape: Cone shape
- Most common type found on land
- Created by layers of ash from initial explosive phases of eruptions and subsequent layers of lava from main eruption phases
- Eruptions: Explosive, unpredictable
- Example: Mount Etna
- Acid or Dome Volcanoes
- Shape: Steep-sided volcanoes . Convex cone-shaped
- Lava: Rhyolitic
- Formed from very viscous lava - as the lava cannot flow far, it builds up
- Location: Continental crust
- Eruptions: Explosive, unpredictable
- Examples: Puy de Domes, France
- Calderas
- Lava: Andesitic
- Location: Destructive margins
- Eruptions: Very explosive, unpredictable
- Form when gases that have built up beneath a blocked volcanic vent result in a catastrophic eruption that destroys the volcanic summit
- Leaves an enormous crater where later eruptions may form smaller cones
- Example: Crater Lake in the US, The caldera has filled with water
- Example: Krakatoa in Indonesia
- Fissure Eruptions
Comments
No comments have yet been made