Volcanic Eruptions

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How Do Volcanic Eruptions Occur?

Trees, houses, fields, roads, and factories can be damaged by volcanic eruptions. There may even be casualties. So how does this natural disaster, which has rendered many places uninhabitable since history, take place?

Trees, houses, fields, roads, and factories can be damaged by volcanic eruptions. There may even be casualties. To understand how this natural disaster, which has made many places uninhabitable since the past, we need to have information about the internal structure of the Earth.

We can directly obtain information about the parts of the world close to the surface, but different methods are used to obtain information about the structure and composition of the deeper layers.

The information obtained so far shows that the earth is made up of different layers. There is the earth’s crust at the outermost, the mantle under the earth’s crust, and the outer core under the mantle. The innermost is the inner core. The temperature of these layers increases as one goes from the earth towards the center. According to researches, the temperature of the inner core is thought to be around 6000 ° C.

The mantle just below the earth’s crust makes up about 84% of the Earth’s volume. It is estimated that the temperature increases as one goes deeper between the mantle layers and reaches approximately 4000 ° C at the outer core boundary. Although determining the composition of the mantle, especially the lower layers, is one of the important difficulties in earth science researches, it is estimated that the mantle consists mainly of rocks consisting of elements such as silicon, magnesium, iron, oxygen, and also dissolved gases and water vapor in the mantle.

The high temperature in the center of the earth causes convection. While the regions close to the center with a temperature of about 6000 ° C move towards the surface with the effect of heat, the regions close to the surface sink towards the center. As a result of convection, tectonic movements occur as the plates in the earth’s crust move. Cracks occur in the earth’s crust as a result of the movements of these plates.
Rocks in the parts of the mantle close to the surface (approximately 100-200 km deep) can be found in a molten state due to high temperature and pressure. Since molten rocks (called magma) are less dense than surrounding solid rocks, magma rises through these cracks to the surface. If the fluidity of the magma is high, the dissolved gases in it easily escape and when the magma reaches the surface, it moves in the form of a lava flow. However, if the fluidity of magma is low, the gases inside cannot escape and magma bursts to the surface with the effect of increasing pressure.