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What happens when two plates collide or separate?
When two plates collide or separate magma can rise from the mantle to fill the gap in the crust.
Through what does magma rise from the mantle?
The magma rises from the mantle through a vent.
What is magma called when it reaches the Earth's surface?
When the magma reaches the earth’s surface it is known as lava.
What does lava form when it cools and hardens?
The lava cools and hardens to form igneous rock.
How is a cone-shaped volcanic mountain formed?
After many eruptions, layers of lava and ash build up around the vent, creating a cone-shaped mountain.
What is an active volcano?
A volcano that has erupted in the past 10’000 years.
What is a dormant volcano?
A volcano that has not erupted in the last 10’000 years but may erupt again.
What is an extinct volcano?
A volcano that is never expected to erupt again.
How are mid-ocean ridges created?
Mid-ocean ridges are created just like volcanoes only they occur in the ocean.
How is the Mid-Atlantic Ridge formed?
The Mid-Atlantic Ridge is created when the North American and South American plates separate from the Eurasian and African plates respectively.
At what rate are the plates at the Mid-Atlantic Ridge moving?
They are moving at a rate of 2cm a year.
What happens when mid-ocean ridges emerge on land?
When they emerge on land they can form Islands. An example of a volcanic island that has formed is Iceland.
What percentage of the world’s active volcanoes are in the Pacific Ring of Fire?
Contains 75% of the world's active volcanoes.
Why do 90% of earthquakes occur in the Pacific Ring of Fire?
Due to many plate movements in this region, 90% of earthquakes also occur here.
Where is the Pacific Ring of Fire located and what is its shape?
Located in the Pacific Ocean and is a horseshoe shape.
How can volcanoes help reduce unemployment?
Tourism: Reduces unemployment and increases the population of an area.
