Are volcanoes scary? You can see their power from their formation, but don't worry about destroying the world!

A nighttime eruption of Mount Etna in Sicily, Italy. The ejected lava was almost 100 metres high and the ash column was almost 5000 metres high. The eruption continued throughout the night and did not end until the morning of the 14th. People in a small village near Mount Etna woke up in the morning and began to clean up the volcanic rock from the eruption. Experts say the eruption was relatively mild, although it lasted.

I was a bit confused when I saw the news. An eruption of this magnitude would only be considered a moderate eruption. But when you think about it, there were no casualties or other significant effects. In retrospect, it seems that I have paid less attention to news about volcanic eruptions. I usually learn about volcanoes by watching disaster-themed TV dramas.

These are the types of dramas that show the power of Conan the Destroyer and seem to tell us that whenever a volcano erupts, we have nowhere to go. In particular, we have the real historical case of Pompeii. So whenever you mention volcanic eruptions, your mind is filled with those terrifying images.

The truth is that most people are scared because they are ignorant. So let me get to know a volcano well and see how scary it is.

Volcanoes are also mountains. Although it is a mountain, it is not like other mountains. Because the volcano is hollow in the middle, it is a passage. This passage leads directly to the upper mantle and the deeper part of the earth's crust, 100 ~ 150 km from the surface. Here there is molten silicate liquid material at high temperature and pressure and magma with gaseous volatile components.

Volcanoes do not form because of mountains, but because of magma eruptions. The magma eruption precedes the formation of the volcano. Volcanoes have the shape of mountains and are formed by the accumulation of underground magma and its solid debris washing out of the ground. The basic components of a volcano are a crater, a magma channel and a volcanic cone.

Volcanoes are usually located at the junction of plates. When one plate moves near another, the two plates squeeze against each other, creating pressure that causes the rock beneath to melt and form magma, and causes the magma to rise. When the pressure is high enough, it breaks out of the ground and spews out magma, forming a volcano.

Volcanoes are also found at non-plate junctions. These volcanoes are caused by the decay of radioactive material inside the Earth, releasing heat that melts the rock, and then as the rock melts or reacts with other materials, it may produce substances such as water and gas, so the magma moves towards the outside of the Earth and builds up to a point where it bursts out of the ground, forming a volcano.

Magma also has the power to move. The Earth can be roughly divided into three layers, the innermost solid material, the middle liquid layer of magma, and the outermost crust. Because the specific gravity of the Earth's innermost solids is greater than that of the magma-liquid layer and the crust, the innermost solids are always tilted in the opposite direction of gravity, away from the centre of the Earth, as the Earth rotates. This creates an inward-to-outward squeezing pressure on the magma-liquid layer, causing gas and liquid material such as magma to move outward from the Earth's interior or erupt to the surface.

They can be divided into active, extinct and dormant volcanoes according to their level of activity. Active volcanoes are those that erupt magma periodically or are expected to erupt again. An extinct volcano erupted in prehistoric times but has never been active or has not erupted for a long period in human history. Dormant volcanoes are volcanoes that have erupted historically but have remained relatively dormant for a long period.

It should be clear, however, that both extinct and dormant volcanoes have the potential to erupt again. Just because they have not erupted since the beginning of human history does not mean that they will never erupt again. It may just be that volcanoes have a longer eruption cycle than humans. Humans are only 5,000 to 6,000 years old. As long as the eruption cycle of volcanoes is longer than five or six thousand years, it is unlikely that we will have any record of relevant eruptions.

Here I would like to give you an example of Pompeii and Herculaneum, which were destroyed and covered with volcanic ash. Pompeii and Herculaneum were built at the foot of Mount Vesuvius in Italy. Before the beginning of the A.D., the famous geographer Strabo concluded that Vesuvius was an extinct volcano based on topographical features. At the time people were fully convinced by his argument and naturally saw nothing wrong with it. However, by the time the volcano erupted, it was too late. Both cities were instantly covered in ash and everything was left intact as it was at the time. Archaeologists are still excavating Pompeii today.

So many hazards are caused by volcanic eruptions. The lava can turn into molten rock and erupt or form lava flows that flow down from the crater and can burn everywhere you go. But the lava flows don't flow too far. When lava comes into contact with seawater, it also produces hot and corrosive gases, lava fog. Lava fog is an irritating mixture of hydrochloric acid gas, steam and volcanic glass particles that is harmful to humans.

Even more dangerous is the volcanic debris flow, which is not a liquid substance, but a dense, hot, high-speed gas stream containing rock debris. Not only is it extremely destructive and deadly, but it is also difficult to escape. The widespread and deadly pyroclastic flows have become the most important destructive force in volcanic eruptions.

In addition, there is volcanic ash. Large amounts of ash are ejected into the sky, covering the sky and spreading with the wind, expanding the area of contamination. The disaster is exacerbated by the assumption of a storm at this time. The rain will turn the ash into mudslides, which form and destroy everything in the vicinity.

Now, these disasters can get bigger as the eruption gets bigger, and the bigger the extent, the more damage it can do. So a small to medium-sized eruption would not be a serious disaster. It's like the news I mentioned at the beginning of my article. The people nearby are not afraid of volcanic eruptions. They get up in the morning to clean up the ash, so they go on with their normal lives. Volcanic eruptions don't seem to concern them. As long as we don't get too close to the volcano, we rarely see an eruption.

It's the big eruptions that can do a lot of damage to humans. But so far we haven't seen an eruption as terrible as the ones in disaster films and TV shows. We don't know if we'll see one in the future, but I believe it's largely unlikely. Under the present environmental conditions, it is unlikely that magma will accumulate so much energy to erupt unless there is a major change. Even if that day does come, all I can say is that there will be nowhere for humans in Conan the Destroyer to escape to then, so don't worry.

I think it's a summary of the main points:

1. volcanoes are formed not because there were originally mountains, but because of magma eruptions. The eruption of magma came before the volcano was formed. Volcanoes have the shape of mountains and are formed when magma and its solid debris rush out of the ground and accumulate. The basic components of a volcano are a crater, a magma channel and a volcanic cone.

2. Volcanoes are generally found at plate junctions. When one plate moves near another, the two plates squeeze against each other, creating pressure that causes the rocks below to melt and form magma, and causes the magma to rise. When the pressure is high enough, it breaks out of the ground and spews out magma, forming a volcano.

3. Volcanoes at non-plate junctions are caused by the decay of radioactive material within the Earth, releasing heat that melts the rock and then turns it. Because the rocks melt or react with other materials, which may also produce water, gases and other substances, the magma moves towards the outside of the Earth and builds up to a point where it bursts out of the ground and forms a volcano.

4. Magma has another power to move. Because the specific gravity of the solid material in the innermost part of the Earth is greater than that of the magma-liquid layer and the Earth's crust, when the Earth rotates, the solid material in the innermost part always tilts in the opposite direction to gravity and is not in the centre of the Earth. This creates an inward-to-outward squeezing pressure on the magma-liquid layer, causing gaseous and liquid materials such as magma to move outward from the Earth's interior or erupt to the surface.

5. Volcanoes can be divided into active, extinct and dormant volcanoes according to their level of activity. However, it should be clear that both extinct and dormant volcanoes have the potential to erupt again.

6. There are still many hazards associated with volcanic eruptions. Lava can turn into lava eruptions or form lava flows. When it comes into contact with seawater, it also produces hot and corrosive gases, lava fog.

7. Even more dangerous are the volcanic debris flows, which are not only extremely destructive and deadly but also difficult to avoid. The widespread and deadly pyroclastic flows have become the most important destructive force in volcanic eruptions.

8. Large amounts of ash are ejected into the sky and dispersed by the wind, continuously expanding the area of contamination. During storms, rain turns the ash into mudflows, creating debris flows that destroy everything in the vicinity.

9. There is no need to worry that a volcanic eruption will destroy the world. Under present environmental conditions, it is unlikely that magma would accumulate so much energy to explode unless there was a major change. Even if there were such a day, Conan the Destroyer, there would be nowhere for humans to escape.