1. Athletic field in Taiwan

2. 6.1 Forces in Earth’s Crust
Stress: a force that acts on rock to change its shape or volume. (This may take millions of years)
3 Types of Stress:
1. Tension: pulls on the crust stretching rock so that it becomes thinner in the middle

3. 2. Compression: squeezes rock until it folds or breaks 3
2. Compression: squeezes rock until it folds or breaks 3. Shearing: pushes a mass of rock in 2 opposite directions

4. Faults: occur along plate boundaries, where the forces of plate motion push or pull the crust so much that the crust breaks 3 types of faults 1. Normal fault: tension in Earth’s crust pull rocks apart; hanging wall slides downward
footwall
hanging wall

5. 2. Reverse fault caused by compression in the crust, the hanging wall slides upward 3. Strike-slip fault rocks on either side move past each other sideways with little up –or –down motion

6. Normal Fault
Reverse Fault
Strike-Slip fault

7. Changing Earth’s surface: over millions of years, the forces of plate movement can change a flat plain into land forms such as *anticline- upward fold in rock formed by compression *syncline- downward fold in rock formed by compression *plateau- large area of flat land elevated high above sea level
Anticline
Syncline

8. *Folded mountains- where 2 plates collide Alps in Europe and Himalayas in Asia *Fault-Block mountains – where 2 faults parallel to each other pull apart, each side slides down Part of the Rockies