Fusion: Earthquakes and Volcanoes

When a big earthquake strikes, the ground shakes. It shakes so much that buildings fall down. Cracks appear in the roads. Bridges can break.
But earthquakes are not always dangerous. Sometimes the Earth only moves a little. This is called a tremor.
Volcanoes often erupt where earthquakes happen. Volcanoes are cone-shaped mountains or hills. A volcano can throw up liquid rock, or lava, from deep inside the Earth.