Plate Tectonics

Introduction

We know very well that the location of the landmass on earth is changing since it was created. In the beginning, there was a huge single landmass on the earth. But by some natural activities, this huge landmass was split into several parts and also move away from its previous location. At present, there are seven huge land masses known as continents. However, these are also drifting from the location. To define this movement of land masses, scientists proposed a theory known as Plate Tectonics.

According to the scientific hypothesis of plate tectonics, the underground activities of the Earth form the main landscapes. The hypothesis, which became firmly established in the 1960s, revolutionised earth sciences by addressing a wide range of phenomena, such as the separation of continents, mountain-building processes, volcanic eruptions, and earthquakes.

What is Plate Tectonics?

We can say that Plate Tectonics as a theory that aims to define and explain how the earth's surface shifts.

On the behalf of the hypothesis of plate tectonics, we can say that Earth's crust is built of huge solid rocky pieces known as plates that plates displace on the mantle. Here, the mantle is a hard layer formed by rocks that lies between the outermost layer and the earth's central core. The upper layer called crust and topmost mantle contributes to developing another layer called lithosphere which is the solid external layer of the earth. Its width is 100 kilometres. The asthenosphere, which is a lubricating layer underneath the lithosphere layer is very flexible due to the heat of the central high-temperature core of the Earth. This flexibility of the asthenosphere causes the motion of the lithosphere by greasing the lower sides of the tectonic plates of the Earth.

Formation of Plate Tectonics

One of the famous scientists explained the formation of Plate Tectonics in his theory. He created a computer prototype of Earth's crust which could have occurred naturally billions of years ago. He proposed his clue, how plates are formed based on mineral grains found in mantle rocks. The model displayed conditions that existed at beginning of Earth's history. He stated that a minimal-pressure zone at the crust's base promoted a section of the earth's crust to fall into the viscus upper mantle.

As this process repeated continuously over ages results in the formation of a huge tectonic plate with a subduction zone. This is the principle of formation of tectonic plates and a huge number of tectonic plates are created the world history.

Types of Plate Tectonics

There are several types of Plate Tectonics.

• Major Tectonic Plates

• Minor Tectonic Plates

• Micro Tectonic Plates

Here, the major tectonic plates are more significant in the study of the movement of the earth’s surface. The major tectonic plates

• African Plate

• Eurasian Plate

• Antarctic Plate

• Indo-Australian Plate

• Pacific Plate

• North-American Plate

• South-American Plate

The largest tectonic plate is Pacific Tectonic Plate which is submerged under the water and extends up to 103,000,000 square kilometres.

Also, Tectonic Plates are classified according to boundaries. There are 3 types of tectonic plate boundaries.

Convergent Boundaries

When two tectonic plates meet at a point or zone known as subduction zones and both press against one another results in the convergent boundary. Here, the ocean plate slips underneath a meeting continental plate and bends downward as a result of the collision.

Divergent Boundaries

When two plates are splitting away from one another, these types of separation at any place are known as divergent Boundaries. The separation creates a space, to fill this space, the molten rock goes up from the centre of the Earth.

Transform Boundaries

When two tectonic plates of the Earth approach each other and slide by side, it forms a transform border. These two plates interact as they pass one another, which may result in the generation of a Transform Boundary at that place.

Facts about Plate Tectonics

Let’s have a look at some interesting facts related to Plate Tectonics.

• On the earth, there are a total of 7 major tectonic plates and a huge number of minor and micro tectonic plates.

• The largest tectonic plate is the Pacific and the smallest one is Juan De Fuca.

• Tsunamis, volcanoes, earthquakes and some other geographical phenomena are caused by the tectonic plates.

• The layer of the mantle on which the Earth's tectonic plates slide and move is called Asthenosphere.

• Every year, plates move by a very small distance hardly more than a few inches.

• In general, tectonic plates are classified into two types; Continental Plate and Ocean Plate. The continental plates are composite of Silica and Aluminium, so these are referred SIAL. On the other hand, Ocean Plate known as SIMA stands for Silica and Magnesium.

• To represent the meeting point of these plates we use a hypothesis area visualization known as Ring of Fire which shows the points on the map where these plates meet.

• The Volcanoes are caused by plates when a heavy plate slips under a light plate and lifts the light plate.

• The cause of the earthquake is the running of plates to each other by the side and sudden snapping produces high-frequency vibrations.

• The Himalayan Range was caused by a head-on collision between two plates; Indian Plate and Eurasian Plate.

• The deepest point on earth is Marian Trench was a caused by convergent boundary formed by the separation of the Pacific Plate and The Mariana plate.

Conclusion

Plate Tectonics are the reason for various natural phenomena, such as volcanoes, earthquakes, continents formation, tsunamis, etc. However, these are very important for the balanced ecosystem on earth because we can see lots of availability like ocean biodiversity, mountains flora, plateau region, etc. Moreover, Plates are in continuous motion.

FAQs

1. Who discovered Plate Tectonics

Alfred Wegener was the first who discovered plates. He introduced his discovery in 1915.

2. What is the average speed of plate tectonics

Plate tectonics are moving at a very slow rate. By historic evidence, we have found that plates are moving at a speed of 100 cm per year. Every plate has the same speed but in different directions.

3. Where is the latest separation of plates tectonics taking place

The latest example of the separation of two plates took place in Ethiopia which was observed in 2005 and this separation continues.

4. Which forces are responsible for the motion of plate tectonics

The motion of plate tectonics is driven by the forces, the force due to gravity at the subduction zone and separation point, heat and pressure in the mantle cause convection.

5. How plate tectonics are responsible for volcanoes

The formation of Divergent boundaries is the cause and the point of origin of volcanoes. This cause was only explained after the discovery of plates.