What is a fault?• A fault is a crack in the Earth’s surface.
Types of fault movement:• Normal Fault: Are faults in which the hanging wall moves down relative to the footwall. This is caused by movement of the fault blocks away from each other. (tension type of stress)• Reverse Fault: The reverse fault is a where the hanging wall moves up relative to the foot wall. This kind of fault is caused by movement of the fault blocks is toward each other(compression type of stress), not away from each other like in the normal fault.• Strike-Slip Fault (Transverse): Movement on a strike strip fault is horizontal, the blocks rub past each other. (caused by shear type of stress)
What’s the big deal?• Why do you think faults are important?
They are important because…• They can be CONSTRUCTIVE!!• They create mountains? – How do you think the movement of faults can create a mountain?• http://www.youtube.com/watch?v=x_WYpKNf snY
But…• They can also be destructive …• Earthquakes occur when there is a sudden movement of rock around a fault.• Discussion: How is an earthquake destructive?