Transform Plate Boundaries

Transform Boundaries Transform Boundary - Place where two plates slide horizontally past each other Crust is not created or destroyed Earthquakes occur but NOT volcanoes

San Andreas Fault San Andreas Fault – Transform boundary that extends through California Runs right through San Francisco Reason why California has a lot of Earthquakes

Reasons for plate movements Plate movements are generally caused by 3 mechanisms: Convection Ridge Push Slab Pull

Convection Current A convection current is the reason for plate movements Hotter parts of the mantle rise while cooler parts sink Puts a force on the lithosphere which drives plate movement

Ridge Push Along mid-ocean ridges new oceanic crust is created as magma rises from the mantle As the magma rises this heats up the rocks around the ridge When the rocks cool they then become denser  This exerts a force on the lithospheric plate and pushes it away from the plate boundary

Slab Pull At subduction zones the denser, oceanic plate is being pulled down Because the plate has a high density it helps “pull” the rest of the plate down as well