Magma is below the surface. It becomes lava when it reaches the surface.
100
Where do most earthquakes occur?
Along plate boundaries/coastlines.
100
What is an active volcano, dormant volcano and extinct volcano?
Active: Has erupted recently.
Dormant: "Sleeping" volcano. Has erupted int he last 500 years.
Extinct: Has never erupted in history.
100
What is Pangea?
The moving and spreading apart of the continents. Also known as continental drift.
100
What are divergent boundaries?
Where plates move apart.
200
What is the focus of an earthquake? The epicenter?
Focus: The point at which an earthquake starts.
Epicenter: The point at which you can feel the earthquake.
200
Why do earthquakes occur?
Plates are shifting. They are either colliding, sliding past each other, or pulling apart.
200
How are volcanos formed?
Magma cracks through the surface and hardens. This cycle continues until a volcano is formed.
and
Plates slide past one another causing the magma to push through the crack.
200
What is sea floor spreading?
Volcanoes on the sea floor erupt causing breaks on the surface. This causes the spreading of the sea floor.
200
What are convergent boundaries?
When plates collide.
300
What is a crater?
The top opening in a volcano.
300
What is a magnitude of an earthquake and how is it measured?
Magnitude is the amount of energy released from an earthquake. It is measured by a seismograph.
300
What are transform boundaries?
When plates slide past one another.
400
What is the difference between the Earth's crust and the mantle of the Earth?
Crust is the outer layer of the Earth. Mantle is below the crust.