Tectonic plates

tectonic plates

In the earth's crust it is divided into different tectonic plates that are in constant movement thanks to the flow of materials that takes place in the earth's mantle. The movement of the different tectonic plates are what generate earthquakes, seas and mountains. The current relief of the world is conditioned by tectonic plates. There are different types and each one has its characteristics.

For this reason, we are going to dedicate this article to telling you about the characteristics, origin and importance of tectonic plates.

What are they

plate boundaries

The tectonic plates, or lithospheric plates, are the different fragments in which the terrestrial lithosphere is divided, the outermost layers of the Earth, including the crust and upper mantle. Seismic, volcanic and orogenic activity is concentrated on its edges.

The latter is due to the constant movement of the tectonic plates on the asthenosphere, the more or less viscous region of the upper mantle, according to the theory of plate tectonics.

The properties of tectonic plates are currently poorly understood, except that they are rigid and their displacement produces geological phenomena such as earthquakes and volcanoes that we can measure and understand. They can even lead to the formation of mountains and sedimentary basins. This is an active phenomenon only on Earth. However, there is evidence that other planets have experienced similar tectonic events.

The theory of plate tectonics that explains these phenomena was formed between 1960 and 1970, as a result of more than two centuries of discoveries, often illegible, of geophysical and geochemical observations and fossil and geological records. Is based on the Theory of continental drift proposed by the German Alfred Wegener (1880-1930) in 1912.

Types of tectonic plates

tectonic plate map

There are two types of tectonic plates in the world: oceanic plates and continental plates.

  • ocean plate. Those are completely covered by oceanic crust, which is the bottom of the ocean, so they're completely submerged. They are thin and composed mainly of iron and magnesium.
  • continental plate. Plates covered by parts of the continental crust, the continents themselves, are the most dominant type of tectonic plate, usually with part continental and part submerged in seawater.

major tectonic plates of the world

plate movements

In total, our planet has 56 tectonic plates, 14 of which are the most important. These are:

  • African plate. It covers the entire African continent and extends into the ocean that surrounds it, except for its northern part.
  • Antarctic plate. It covers all of Antarctica and then the nearly 17 million square kilometers of surrounding ocean.
  • Arabian plate. Located under the Arabian Peninsula and part of the so-called Middle East, it comes from the fracking of the African plate and has 43% of the world's natural gas reserves and 48% of its oil reserves.
  • Coconut Plate. It is located under the Pacific Ocean on the western coast of Central America, next to the Caribbean plate, which forms the Mesoamerican volcanic arc under the Caribbean plate.
  • Nazca Plate. Beneath the eastern Pacific Ocean, the coasts of Peru, Ecuador, and Colombia, as well as north-central Chile, subduct under the South American plate to form the Andes.
  • Juan de Fuca Plaque. A small plate on the western side of the North American Plate, along the Pacific coast of California, Oregon, Washington, and British Columbia. This, along with the Cocos and Nazca plates, comes from the disintegration of the old Farallón plate about 28 million years ago.
  • Caribbean Plate. As its name indicates, it is found in the Caribbean, northern South America, and eastern Central America, covering an area of ​​more than 3,2 million square kilometers. It covers parts of the Central American continent (Guatemala, Belize, Honduras, Nicaragua, El Salvador, Costa Rica, Panama, and the Mexican state of Chiapas), as well as all the Caribbean islands.
  • Pacific Plate. It is one of the largest oceans on Earth, covering almost the entire ocean of the same name, and has many "hot spots" and seismic or volcanic belts, especially around Hawaii.
  • Eurasian plate. This gigantic plate covers an area of ​​67,8 million square kilometers and covers the entire Eurasian continent (all of Europe and Asia), except for parts of the Indian subcontinent, Arabia, and Siberia. It also extends several kilometers east of the North Atlantic.
  • Philippine plate. Located in the Pacific Ocean east of the Philippines, it is a subducting plate in the Mariana Trench region. Compared to its neighbors, it is very small.
  • Indo-Australian Plate. As its name suggests, this plate stretches from India's borders with China and Nepal, through the entire Indian subcontinent, the Indian Ocean, and all of Australia and Melanesia, finally reaching New Zealand. It is the result of the fusion of ancient Indian and Australian plates about 50 million years ago.
  • American plate. It contains all of North America, including Greenland, as well as the Cuban archipelago, the Bahamas, half of Iceland, and part of the North Atlantic, the Arctic glaciers, and the Siberian territories. It is the largest plate on Earth.
  • Scotia plate. It is found at the junction of the Pacific Ocean, the Atlantic Ocean, and the Antarctic glacial oceans in southern South America. It is a smaller and relatively new plate, born in the Cenozoic. It has strong earthquakes and volcanic activity.
  • South American Plate. Like its namesake continent, this plate underlies all of South America and also extends southeast into the South Atlantic.

Movement

The tectonic plates move over the asthenosphere, the fluid part of the mantle. They move at different speeds, usually slow but steady, so they are imperceptible unless they collide with other objects, and then we perceive the seismic waves that impact.

The reason for these motions is not well understood, but it may have something to do with Earth's rotation, hot magma moving up and cold magma moving down, or even the difference in gravity and gravity. density of the planet's crust.

However, these movements are part of the dynamics of the mantle, where there is convection and heat distribution, which keeps matter semi-solid and denser, heavier elements descend to make room for lighter elements.

I hope that with this information you can learn more about tectonic plates and their characteristics.


Leave a Comment

Your email address will not be published. Required fields are marked with *

*

*

  1. Responsible for the data: Miguel Ángel Gatón
  2. Purpose of the data: Control SPAM, comment management.
  3. Legitimation: Your consent
  4. Communication of the data: The data will not be communicated to third parties except by legal obligation.
  5. Data storage: Database hosted by Occentus Networks (EU)
  6. Rights: At any time you can limit, recover and delete your information.