Types of Faults

Rocks Move Along Faults break in Earth’s lithosphere, where blocks of rock move past each other At some parts of a fault, the rock slides slowly or constantly. At others it sticks or locks together. Rock bends and stretches as stress is put on it ( think of a rubber band or popsicle stick)

Earthquake Earthquake Strength of an earthquake depends on shaking of the ground caused by the sudden movement of large blocks of rock along a fault Occurs when there is a sudden release of stress in the lithosphere. when the rocks break free from being stuck Strength of an earthquake depends on The amount of stress built up The distance the rocks move along the fault

The rocks that move Most faults are along tectonic plate boundaries Most earthquakes occur here The rocks that move during an earthquake are smaller than tectonic plates Rarely do earthquakes happen in the middle of the plate.

Types of faults Faults are classified by how they move This is determined by the kind of stress the rocks are under More than one type of fault can happen at a plate boundary

Normal Fault Occurs when stress pulls the rocks apart One chunk goes down the other shifts up. Earthquakes happen where chunks of rock are moving apart The Great Rift Valley of Africa. force force Movement of rocks

Reverse Fault Occurs when stress presses rocks together One chunk ends up on top of the other. Occurs near convergent collision-zone boundaries between plates force force Movement of rocks

Strike Slip Faults Occurs when stress pushes rocks horizontally Blocks of rock move sideways on either side of the fault plane. Happens when plates scrape past each other force force Movement of rocks