What are Tectonic Plates?

Michael Anissimov
Michael Anissimov

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.

Mountains, such as Mt. Everest, are created when tectonic plates push against each other.
Mountains, such as Mt. Everest, are created when tectonic plates push against each other.

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.

Continental drift, a forerunner of plate tectonics, explained how the current continents once likely fit together.
Continental drift, a forerunner of plate tectonics, explained how the current continents once likely fit together.

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.

Volcanic islands have been formed due to plate tectonic movement.
Volcanic islands have been formed due to plate tectonic movement.

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.

The Earth's tectonic plates may rise together, drop downward, shear, or overlap at their point of contact.
The Earth's tectonic plates may rise together, drop downward, shear, or overlap at their point of contact.

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.

Now inhospitably cold, Antarctica was once a temperate continent with forests.
Now inhospitably cold, Antarctica was once a temperate continent with forests.
Michael Anissimov
Michael Anissimov

Michael is a longtime wiseGEEK contributor who specializes in topics relating to paleontology, physics, biology, astronomy, chemistry, and futurism. In addition to being an avid blogger, Michael is particularly passionate about stem cell research, regenerative medicine, and life extension therapies. He has also worked for the Methuselah Foundation, the Singularity Institute for Artificial Intelligence, and the Lifeboat Foundation.

You might also Like

Readers Also Love

Discussion Comments

anon327430

How come the continental shelf floats on top?

anon255704

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.

anon242674

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

dwyerbr

what do tectonic plates have to do with earthquakes?

what role in an earthquake do tectonic plates have?

anon191971

how do tectonic plates move?

anon167462

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.

anon161988

why did they call them tectonic plates?

anon158372

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

anon147158

What is the evidence of the theory of Tectonic Plates?

anon146682

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!

anon127259

What are the main major tectonic plates?

anon127214

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

anon113452

Thanks you so much this will help my test!

anon106515

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

anon103819

There are three types of tectonic plates :

1.constructive

2.destructive

3.conservative

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.

anon100234

thank you for giving me information.

anon94097

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

anon89422

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

anon88615

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

anon87416

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.

anon83725

how many inches do the tectonics move in 20 years?

anon83045

thanks a lot. it really helped.

anon82608

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

anon80482

What ways can they interact?

anon76161

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

anon72094

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

anon65943

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

anon62924

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.

anon61353

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

anon60333

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

AnissimovM

They move in different directions.

anon12808

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

Post your comments
Login:
Forgot password?
Register: