Chapter 6 Earthquakes

Forces in the Earth’s Crust stress -a force that acts on a rock to change its shape or volume - “pushing” and “pulling” of rocks Rock deforms in 3 ways: -compression -tension -shearing

Kinds of Faults fault -a break or crack along which rocks move *location of earthquake movement Two areas of most faults: hanging wall -block of rock above the fault line foot wall -block of rock below the fault line

Forces in the Earth’s Crust compression squeezes the rocks of the crust until it folds or breaks -the rock becomes more dense -convergent boundary

Kinds of Faults reverse fault -a fault in which the hanging wall moves up the footwall *caused by compression* Hanging wall Footwall

Hanging wall Foot wall

Forces in the Earth’s Crust tension -pulls on the rocks of the crust, causing rocks to stretch out over a large area -rock becomes less dense -divergent boundary

Kinds of Faults normal fault – a fault in which the hanging wall moves down along the fault line above the footwall *caused by tension*

Hanging wall Foot wall

Forces in the Earth’s Crust shearing -pushes rock of the crust in two different directions -density does not change -transform boundary

Kinds of Faults strike slip fault -a fault in which the blocks of rock move past each other sideways. There is very little “up” and “down” motion. (thrust fault) *caused by shearing*

Name: Date: Class: 6.1 Pop Quiz

#1 #2 #3 What type of fault is this?

#4 #5 #6 What type of fault is this?

#7 What type of fault is this?

#9 #8 #10 What type of fault is this?

#11 #12 #13 What type of fault is this?

#14 What type of fault is this?

Changing Earth’s Surface Scientists use the terms anticline and syncline to describe upward and downward folds in rock. anticline – a fold in rock that bends upward syncline – a fold in rock that bends downward

Changing Earth’s Surface plateau – a large area of flat land raised high above sea level -formed when forces in the Earth’s crust push up large, flat blocks of rock