Volcanic eruptions: definition and types

A volcano is a cone-shaped geological formation with a hole or crater at its top. It is formed by the movement of the large plates that are under the surface of the earth, the tectonic plates . These always have movement, but when it is very strong, earthquakes , cracks appear and, when a couple or more of these plates collide, mountains, islands and volcanic formations also appear. This responds to how volcanoes are formed , that is, they appear when plates collide and cause the earth to rise, leaving channels and chimneys, through which the lava that forms from the magma inside the Earth then comes out.

The volcanic eruptions , are the result of the temperature rise in the core and movement of the Earth. As the usual temperature of magma increases greatly, it rises to the surface through channels and vents found in volcanoes.

The violence or force of the volcanic eruption is given by the temperature and acidity of the lava, by the gases emitted, by the level of silica in the lava, since the more silica it contains, the greater the explosion, and by the state of the chimney, because if it is obstructed the explosion will be more violent.

Simply explained, there are different types of volcanoes depending on their shape, composition and the way in which their eruptions, explosive or milder, occur. Thus, the different types of volcanoes and types of volcanic eruptions are known by the same name, for example, Hawaiian explosions correspond to Hawaiian-type volcanoes. These are the different types of volcanoes and eruptions:

• Hawaiian
• Strombolian
• Vulcanian
• Pliniana or vesuviana
• Fight
• Surtseyan or marina

Another way to classify these geological formations is to think about their state of activity, rather than their formation and their type of eruption. Thus, according to the activity of the volcanoes, we can classify them as follows:

• Active volcanoes: are those that can erupt at any time. Normally active volcanoes are young, but they don’t have to be.
• Dormant or dormant volcanoes: these are those that spend long periods without activity, but that can recover it, that is, wake up at any time, becoming active volcanoes.
• Extinct volcanoes: they are those that will never be active again, due to changes in the geological formation of their area. Therefore, its activity has completely ended and a large mountain with a crater remains.

Next, we explain each of the types of volcanic eruptions with its definition , to easily learn to differentiate them well:

Hawaiian eruptions

These are the most common types of volcanoes and eruptions in the world, and they are so named because Hawaii’s volcanoes are like that. Its lava is very fluid and there are no large explosions because they hardly contain explosive gases, therefore, the magmatic lava overflows through the crater forming rivers of lava down the slope, which can travel great distances before cooling and hardening. Due to this form of eruption, these formations have a very gentle slope, since the lava materials when descending in this way form a volcanic cone with little slope.

Strombolian eruptions

The name of these eruptions is due to Stromboli, the volcano found in Lipari, Italy. Its lava is fluid and contains explosive and toxic gases, which produce violent explosions , although no ash is produced, and which can last for years. When the lava materials fall down the slope, they descend forming the cone, but they do not travel as much distance as in the case of the Hawaiian eruptions, because it cools earlier.

Vulcan eruptions

This other type owes its name to Vulcano, another volcano that is in Italy. Its lava magma is viscous rather than fluid, so it hardens quickly. The eruption of this type of volcano occurs with rapid and very strong explosions , with many gases and ashes. They are some of the most spectacular eruptions and can last several days or even months.

Plinian eruptions

They are very violent eruptions and their name is in memory of Pliny the Elder, who died in one of them. They are similar to the Vulcanians, but the Plinians have more violent explosions, due to the pressure of the gases being much stronger, and they are usually shaped like a mushroom or mushroom. When the materials from the blast cool down, they form ash clouds that can completely cover entire cities. The volcano of Mount Vesuvius and what happened in Pompeii, which was buried by its ashes, are a clear example.

Fighting eruptions

In this eruption, the lava is very viscous, so much so that it forms a plug in the crater and the pressure of the gases expels it violently, even breaking part of the crater. It can also happen that before the cap is raised, some part of the slope gives way and the lava is thrown out of the side. Its name comes from Mount Pelée, a volcano in the Antilles.

Surtseyan or submarines

They tend to go unnoticed when underwater , but in reality they are more frequent than the others. Its name is due to the fact that an eruption of this very important type happened in Surtsey, Iceland. In these cases, a cloud of water vapor and ash usually rises, which can be seen or not depending on the depth of the point where the eruption occurs and its strength.

Volcanic eruptions can have serious consequences on a material, ecological and human level. That is why volcanic areas have to have planned the actions that must be carried out at the moment in which an eruption begins. Next, in AgroCorrn, we explain the series of measures to reduce the effects of volcanic eruptions :

• Establish escape routes.
• Identify the areas of influence of the volcano near our house.
• Cover the cracks in windows and doors with duct tape to keep ashes out.
• Cover the water tanks to avoid contamination.
• Have a kit with emergency supplies, such as a mask and an eye shield, ready.
• Stay informed and follow the instructions of the authorities and volcanologists.

One of the best ways for children to learn how volcanoes work and what volcanic eruptions look like is to do a fun and simple science experiment: make a volcano out of simple materials.

Material

• 1 tall, thin bottle or bottle with cap
• Earth or sand
• ¼ cup of water
• ¼ cup of baking soda
• ¼ cup vinegar

Steps to make a volcano

1. Find an area in your garden where you can make a small mountain of sand as tall as the bottle and shaped like a cone, leaving a hole in the center where the entire bottle should fit.
2. Aside, pour the water and bicarbonate into the bottle, mix well and close with the cap.
3. Place the bottle on the volcano-shaped sand mountain.
4. Open the bottle and pour in the vinegar little by little. Then you will see the reaction that simulates a volcanic eruption.