The Earth's continents are formed by the movement of tectonic plates. Tectonic plates are large pieces of the Earth's crust that move around on the Earth's mantle. When two tectonic plates collide, one plate may be forced beneath the other, a process called subduction. Subduction can cause the formation of mountains and volcanoes. The continents are made up of less dense rocks, such as granite, that float on the denser rocks of the mantle.

Mountains

Mountains are formed by the movement of tectonic plates. When two tectonic plates collide, the rocks on the edges of the plates can be pushed upwards, forming mountains. The highest mountains in the world, the Himalayas, were formed by the collision of the Indian Plate and the Eurasian Plate.

Ocean Basins

Ocean basins are formed by the spreading of tectonic plates. When two tectonic plates move apart, new crust is created in the gap between them. This new crust is called oceanic crust and it is made up of denser rocks, such as basalt. The ocean basins are filled with water.

The internal structure of the earth influences the creation of continents, oceans and mountain ranges in a number of ways.

- The movement of tectonic plates creates new crust, which can form continents and ocean basins.

- The collision of tectonic plates can cause the formation of mountains and volcanoes.

- The density of the rocks that make up the Earth's crust and mantle also plays a role in the formation of these features.