1. Heat from the Earth's Core: The Earth's core is incredibly hot, and this heat is constantly transferred outward towards the mantle.
2. Mantle Convection: The mantle is a semi-solid layer of rock that behaves like a very viscous fluid over long periods. The heat from the core causes the mantle to heat up and become less dense. This less dense material rises, creating convection currents. Cooler, denser material sinks back down to be reheated, creating a continuous cycle.
3. Plate Movement: The Earth's tectonic plates sit on top of the mantle. The convection currents within the mantle exert a force on the plates, causing them to move.
4. Divergent Plate Boundaries: Where convection currents rise, they pull the plates apart, creating divergent plate boundaries. Here, magma from the mantle rises to the surface, forming new crust.
5. Convergent Plate Boundaries: Where convection currents sink, they push the plates together, creating convergent plate boundaries. Here, one plate may slide under the other (subduction) or the two plates may collide and buckle, forming mountains.
6. Transform Plate Boundaries: Along transform plate boundaries, plates slide past each other horizontally. This movement is often triggered by the pressure of the convection currents.
In summary: The heat from the Earth's core drives convection currents in the mantle, which in turn cause the movement of tectonic plates. This movement leads to the formation of mountains, volcanoes, earthquakes, and ocean basins, shaping the Earth's surface over millions of years.
