Fact 1: Faulting of rock in Earth 's crust causes earthquakes.

Fact 2: Earthquakes tremors both mild and moderate are frequent occurrences in the park and preserve.

Given the two facts above, answer the question "What causes tremors?" with the following options: 
- thunder
 - Electrical energy
 - fire
 - faulting of rocks
 - sensory neurons
 - energy of moving objects
 - tornadoes
 - electromagnetic energy


 

    faulting of rocks     