The continents are large areas of land that dominate against the background of nearby archipelagos and islands. Of course, this is a general definition. If we consider the continents from the point of view of science, then this is not only land areas, but also the sea shelf, which is one with the mainland, but has long been hidden under water as a result of flooding. Often, children have questions, for example, why do continents move? Let's see if this is actually so.
Liquid magma and solid land
To understand why the continents move, you should study the structure of the planet. So what is solid land? First of all, it is part of the earth's crust. Solid land is just a thin layer of various rocks that hide hot magma beneath them. The thickness of the earth's crust can vary greatly. For example, under the ocean, the depth of solid rocks can range from 13 to 350 kilometers, and the depth of liquid magma can be almost 5,000 kilometers. The difference, of course, is significant.
Why is magma liquid? The main reason is the high temperature, which is released as a result of thermonuclear reactions that occur in the core of the planet. The substance is very hot. In this case, magma moves from the center to the earth's crust, where its cooling processes take place. Convection is constantly observed in the liquid layer, which are recorded by satellite magnetometers. This phenomenon allows us to answer the question of why the continents move. A brief description of such processes allows you to fully imagine the picture of what is happening.
The main reason for the movement of the continents
So why are the continents moving? The answer to this question is quite simple. Convection inside the magma is chaotic. Very often, less activity is shown in certain areas than in others. It is worth noting that the rise of magma proceeds under great pressure and very slowly. However, when such phenomena occur, a large amount of kinetic energy is released. All this has a definite effect on solid land.
Magma performs cyclic movements. It pushes surface fragments exactly in the direction where the impulse is present. That is why the continents move. In other words, the surface displacement of solid land is associated with the processes that occur inside our planet right down to its core.
How do continents move
The reason why the continents move has been established for a long time. Experts note that the displacement of solid land is negligible. In a year, continents can shift by only one centimeter. However, the energy that is released during the course of such processes is much more than the network of power plants can generate.
It was found that glaciers also influence the movement of continents. In some places, the ice shell of Antarctica is able to push the surface of the earth's crust up to two and a half kilometers inland. As a result of this, the displacement of the continents slows down significantly.
Have continents always moved
The movement of the earth's crust did not begin immediately, because at first our planet was a liquid molten ball. Gradually, the Earth cooled, its surface was covered with a hard crust, and only after 500 million years did continents form. The resulting land cracked under the pressure of hot magma. So the future surface elements were formed. Those located higher began to form land. Part of the plates, due to a sufficiently large weight, plunged deep into the planet and became oceanic. Under the influence of magma, the earth's crust moved. These processes lasted about 3 and a half billion years. Plates collided, lifted and squeezed. As a result, the oceans, seas and continents that currently exist are formed.