Why are there volcanoes on Earth

One of the most dangerous events on our planet is volcanoes. The Volcanic eruptions they are violent emissions capable of destroying civilizations completely, although they are also precious natural events seen from afar. To better understand the causes of volcanoes and their origin, in this lesson from a PROFESSOR we are going to talk about why are there volcanoes on Earth.

The volcanoesthey are geological structures from which magma can arise. Magma arises in violent situations called eruptions, which can be mild and leave no damage or extremely strong and destroy everything around them.

The term "volcano" was coined by the Romans, coming from the word of the Roman god Vulcan, god of fire and patron of furnace trades. The Romans related lava to the red hot iron of Vulcan's works, and the volcano to the fire that Vulcan represented. The Roman influence is such in our culture that the name has been maintained throughout the centuries, currently there is a relationship with the Roman god.

It should be taken into account that volcanoes do not exist only on our planet, since they also can be found on other planets and satellites. A curiosity is that the colder climate of other planets causes cryovolcanoes to exist, with ice instead of rock, an example being those found in Europa, satellite of the giant Jupiter.

To continue with this lesson about why there are volcanoes on Earth, we must talk about the reasons volcanoes exist and how they arise.

Volcanoes are geological structures and therefore have a great relationship with the interior of our planet. The Earth has a solid central core, surrounded by a semi-solid outer layer and then a mantle, the latter being where the lava is found. This mantle is divided into two, the lower mantle that is the one that arises directly from the outer layer and the upper mantle that goes to the crust.

The Cortex It is formed by the tectonic layers, therefore it is not totally uniform. The movement of the plates is called continental drift and is carried out on the basaltic mantle, this being the place from which the lava that emerges from the volcanoes comes.

Continental drift has fissures, that is, separations between tectonic plates, which when they occur on land form volcanoes. In turn, the crust is being destroyed, as some plates sink below others, causing the phenomenon called subduction. The areas where these subductions occur have great pressures, and that causes volcanoes to form.

Where volcanoes originate

For all this we can say that the older generation place of volcanoes is the boundary between tectonic plates, since it is the fissures and subductions of these plates that cause the appearance of volcanoes. As an example of this type of zone we must speak of the Pacific Ring of Fire, a place with a lot of subduction, which causes it to have a great activity of volcanoes.

Although most volcanoes appear on the border between tectonic plates, there are other types of volcanoes that do not have to appear at those points. These volcanoes appear in so-called hot spots, places with high volcanic activity that can appear in places far from the limits of the plates. Examples of hot spots would be Hawaii and the Canaries.

Not all volcanoes on Earth are the same, there are several types that can vary depending on the type of eruption they have. Some of the types of volcanoes according to their eruption are the following:

• Hawaiian: Characterized by a fluid lava and hardly any gaseous explosions.
• Strombolian: Fluid lava with an abundance of violent gases. Its name comes from Stromboli, a Sicilian volcano.
• Vulcanian: It is characterized by not very fluid lava, with a large amount of gases and a lot of ash.
• Pliniana: Very violent explosions that expel a huge amount of ash. Such is the amount of expelled ash that it can even bury cities like Pompeii.
• Fight: Washes very viscous that consolidates with great speed. In this eruption a plug is created that prevents the exit of gases and magma, causing a large explosion.