2 PlateTectonicsThe theory that states that pieces of Earth’s lithosphere are in constant, slow motion, driven by convection currents in the mantle.
3 The theory of plate tectonics explains the formation, movement, and subduction of Earth’s plates.
4 Forces that causes Earth’s plates to move. The plates of the lithosphere float on top of the Asthenosphere.Convection currents rise in the Asthenosphere and spread out beneath the lithosphere.Convection current forces drag the overlying plates along. The currents cools and sinks deeper into the mantle.Scientist think that the downward movement may provide the force that causes the subduction of plates carrying oceanic crust.
6 Slab Push HypothesisMagma rising along the mid oceanic ridge exerts a force that pushes an oceanic plate away from the ridge.The force of gravity causes plate movement by pulling cooler, denser oceanic plates down toward the mantle.Slab push and pull work together with convection currents to move the plates.
7 The earth’s surface is made up of about nine large plates & several smaller plates.