Major Plates of the Lithosphere: Earth's Tectonic Plates

Mid-Atlantic Ridge

A large underwater mountain range on the floor of the Atlantic Ocean is caused by diverging (going in different directions) tectonic plates. As the two ridges spread apart they allow magma from deeper layers to seep up on the ocean floor to form new layers of oceanic crust ... a ridge.

North American Plate

Extends from the middle of the Atlantic Ocean to the west coast of North America.

South American Plate

Extends from the middle of the Atlantic Ocean to the west coast of South America.

African Plate

Includes Africa and surrounding oceanic crust ... both Atlantic and Pacific.

Eurasian Plate

Includes most of Europe and Asia and nearby oceanic crust.

Indo-Australian Plate

Includes the Indian subcontinent, Australia, and the surrounding oceanic crust.

Antarctic Plate

Includes the continent of Antarctica and the surrounding oceanic crust.

Pacific Plate

It is the largest plate and the only one mainly underwater ... in the Pacific Ocean.

Tectonic Plates are also called Lithospheric Plates

Remember, the Lithosphere is the outermost shell of the Earth, made up by the upper part of the mantle and the crust.

Composition of Tectonic Plates

Some contain land, some water, and some contain both.

Asthenosphere

The hotter and more fluid layer below the Lithosphere is the Asthenosphere. It is what the tectonic plates float on.

Major Tectonic Plate Names

There are seven (7) large tectonic plates that slowly move around on the surface of our planet ... along with some minor one. Six (6) of the seven (7) major plates are named after the continents they contain. The exception is the Pacific Plate.

Tectonic Activity

What occurs when two tectonic plates meet? When they meet they could be moving towards each other, sliding past each other, or pulling apart. These cause mountain building, earthquakes, tremors, and volcanoes.