1. what causes the earth to shake?

1. what causes the earth to shake?
Answer
Brief Explanations:
Earthquakes are mainly caused by the sudden release of energy in the Earth's crust, which occurs when tectonic plates move and interact. Volcanic eruptions can also cause the Earth to shake as magma movement and explosions release force.
Answer:
Earthquakes (due to tectonic - plate activity) and volcanic eruptions are main causes.