Why tectonic plates move?

Human life would be meaningless if Earth did not exist. The planet we live on has unique characteristics that make it a very special planet. One of these qualities is that it is "alive." The Earth's surface is a puzzle of different plates, which move, transforming the landscape of our planet. Due to the importance of these plates, today in this lesson from a PROFESSOR we are going to talk about “Why tectonic plates move?”.

A tectonic plate it is a fragment of lithosphere that moves as a relatively rigid block on the upper mantle of the Earth. Plate tectonics is what explains the dynamic character of the Earth's surface. The lithosphere is made up of several tectonic plates, which are in continuous motion.

The movement and collision of tectonic plates can lead to different phenomena, such as earthquakes, the formation of volcanoes or the formation of mountains. This dynamism is also responsible for the Earth being a habitable place, since if the planet were a cold and inert rock, without movement, it would surely not be suitable for human life.

Currently we can know exactly the tectonic plates of which the earth's surface is formed. They are 15 major or major tectonic plates and some 42 secondary or minor tectonic plates.

The movement of tectonic plates can be due to two fundamental causes, which are:

• Convection currents
• The gravity

Convection currents

They are produced by temperature and density difference between tectonic plates. Warmer materials weigh less and therefore rise, while cooler materials descend because they are denser and weigh more.

The mantle is solid, but it behaves like a kind of plastic material, deforming and stretching without breaking. This may be due to the high temperature they get. When the part of the mantle warms up, and when it cools it sinks, repeating this process several times generates a movement, which is the cause of the displacement of the tectonic plates.

In the deepest parts of the mantle, close to the core, the heat is very intense, which causes large masses of rocks to partially melt and then slowly rise, this causes warm updrafts that contribute to the fragmentation of the continents. On the other hand, we find that large fragments of cold lithosphere sink into the mantle, causing a series of downdrafts that reach the base of the mantle. The updrafts and downdrafts of the mantle are the cause of the movement of the tectonic plates.

The gravity

The other fundamental cause of plate movement is gravity. Some geologists consider that convection currents is not enough to move tectonic plates, especially considering that warm updrafts are sporadic. That is why some experts consider that gravity is the main cause of the movement of tectonic plates.

It is considered that in subduction zones, When the oceanic lithosphere sinks, it carries the rest of the plate with it. According to this, the magma hardly influences the movement, but its function would only be to fill a hole.

Continuing with the lesson of "why do plate tectonics move?" we should talk about the area of ​​greatest movement incident. The greatest tectonic movement of the plates takes place at their limits, so it is important to know the different types of limits that the squares have. There are three types of limits:

• Divergent boundaries or construction edges: Lithospheric plate separation zones, and where a new oceanic lithosphere is generated.
• Converging boundaries or destructive edges: Where the plates approach and push, therefore is where the oceanic lithosphere is destroyed. It is situated near the edges of the continents.
• Transforming boundaries or passive edges: They are neutral limits, where neither lithosphere is created nor destroyed.

Due to the movement of tectonic plates, the continents have suffered movements that has forced them to separate from each other, this is called continental drift. The fact that the continents have separated has had a series of consequences, among which we must highlight:

• The sea level: Sea level changes depending on whether the continents are together or apart.
• The weather: The united continents stage has always been colder than when the continents have been separated.
• The distribution of living things: Depending on when the continents separated, the animal species of each have more or less similarities with those of other continents.

For all this it is important to know the movement of the tectonic plates. Since if this movement did not exist, our world would be very different from the one we currently live in.