Fact 1: An earthquake causes the ground to shake.

Fact 2: Earthquakes are movements in the Earth's crust.

Given the two facts above, answer the question "what causes the ground to shake?" with the following options: 
- high temperature
 - movements in the earth's crust
 - human migration
 - exposure to cold
 - cloud formation
 - energy of moving objects
 - soil
 - degrees Celsius


 

  movements in the earth's crust       