The Earth is producing new crust where two plates are diverging or spreading apart.

The Earth is a dynamic or constantly changing planet. Plates are in constint motion causing earthquakes, mountains, volcano building, and the procces of new crust and destruction of old crust.

A subduction zone is a place where a contenental plate and a oceanic plate collide which makes the ocecanic plate go down which forms islands.

The earth is composed of four different layers. Many geologists belive that the Earth cooled and the dence matirials sunk and the light matirial went to the top. The Earth's crust has been compared to an apple skin because it is very thin compared to the other layers. the mantle is the largest layer on the earth 1800 miles thick.