What are Tectonic Plates?

Tectonic plates are large plates of rock that make up the foundation of the Earth's crust and the shape of the continents. The tectonic plates comprise the bottom of the crust and the top of the Earth's mantle. There are ten major plates on Earth and many more minor ones. They float on a plastic-like part of the Earth's mantle called the asthenosphere. The plates are most famously known for being the source of earthquakes.

The tectonic plates are about 100 km (60 miles) in thickness, with continental plates tending to be thicker than oceanic ones. The composure of the two types of plate is also quite different. Oceanic plates consist of thicker basaltic rocks, compressed by the pressure of kilometers of water. Contintental plates have a lower average density, containing granitic rocks with a heavy composition of aluminum and silica.

The mantle underneath the tectonic plates is constantly recirculating, causing the plates to float around slowly in a process called tectonic drift. This process was described well by the theory of plate tectonics, which solved several scientific dilemmas about the distribution of species when it was introduced. When plates push up against each other, they create mountain ranges and volcanoes. Mt. Everest was created in this way.

Because the plates are so large, each wraps over a considerable portion of the Earth's surface, making them curved. This is a different shape than the flatness the word "plate" suggests.

Over time, plate tectonics has caused the world's continents to be reshaped. Every continent on Earth was once part of an ancient supercontinent known as Pangaea, and Antarctica was once located in a temperate climate. Marine fossils can be found on the peaks of the world's tallest mountains. The tectonic plates continue to move slowly, but it is unlikely that their movement will cause the world's face to change more rapidly than the growing technological influence of mankind will. One day the plates' great momentum and pressure might even be used as a source of geological energy.

You might also Like


Discuss this Article

Post 66

How come the continental shelf floats on top?

Post 56

I am Alicia. I am reporting from a devastating earthquake that just happened in Kyrgyzstan. I love that place because my uncle lives there, but he died by jumping out of the window from a two-story high building.

Post 55

Wow. This is very good. I used some info and it was totally understandable!

Post 54

what do tectonic plates have to do with earthquakes?

what role in an earthquake do tectonic plates have?

Post 53

how do tectonic plates move?

Post 49

tectonic plates have nothing to do with oil so don't panic they slide on molten rock and all they have to do with oil is plate movement can cause fold rock which can trap oil as in the persian gulf or near the caspian sea near baku in Azerbaijan.

And they move in any direction, mainly horizontal, but as far up and down as Mt. Everest and the Marianas trench.

Post 48

why did they call them tectonic plates?

Post 44

Does the rubbing together of tectonic plates cause a Tsunami? What other things does it cause?

Post 41

What is the evidence of the theory of Tectonic Plates?

Post 40

If they keep raping this planet of its oil these plates will certainly reorganise this planet after major eruptions. It's the oil in the earth and oceans that keeps them slowly moving so as not to seize up, creating disasters!

Post 39

What are the main major tectonic plates?

Post 38

How are the tectonic plates related to the formation of the Hawaiian Island chain?

Post 35

Thanks you so much this will help my test!

Post 33

did you know that tectonic plates only move a few centimeters prayers? it grows as fast as your fingernail grows.

Post 32

There are three types of tectonic plates :




Constructive plates: When two plates move towards each other, the gap left between two is then filled with

magma, rising up from the hot interior of earth. Finally, the lava flows on earth's surface, forming up volcanoes and new land, hence named a constructive plate boundary.

Destructive plates: When two plates move towards each other, one comes under other and is destroyed. Hence, they are named destructive boundaries.

Conservative plates: When two plates move against each other at different speeds and the stress is built up,

which releases occasionally as sudden movements of the surface, creating faults in the surface and causing earthquakes.

Hope you all will understand. It's very easy.

Post 30

thank you for giving me information.

Post 29

thank you very much. it really helped me a lot. wonderful site.

Post 28

this is a great site. it has everything you need to know. well, almost everything.

Post 27

How do the tectonic plates form the continental shapes? Doesn't mention it there.

Post 24

Tectonic plates move in all sorts of directions, that is why mountains are created. The tectonic plates crash into one another and the rock is pushed upwards.

Post 21

how many inches do the tectonics move in 20 years?

Post 20

thanks a lot. it really helped.

Post 19

Thank you, author, for this fact-filled article. It was very helpful.

Post 16

What ways can they interact?

Post 13

Thanks for all the information. This information really helped me out a lot. --jalisa1232

Post 12

how do tectonic plates move? Please explain, or tell me about the source from where i can get the answer. thanks.

Post 11

Giving that plates are moving in either direction, at a known distance, would we be able to harness this energy.

Post 9

They move side to side, back and forward, all various ways. Slightly. This is called tectonic flow or something like that (forgotten). Each tectonic plate moves in their own direction.

Which part are the tectonic plates in? It isn't in anything, it is on top of the earth crust.

And a Tectonic plate doesn't move very fast, actually depends on various things.

Fact: Mount Everest was made by tectonic plates.

Post 7

what part of the earth are the plates in? the crust?

Post 5

How fast does a tectonic plates move and which way does a tectonic plate move?

Post 2

They move in different directions.

Post 1

Which Direction do tectonic plates move in? Do they move in all different directions?

Post your comments

Post Anonymously


forgot password?