What is a Volcanic Eruption & How Does it Affect Us?

Introduction

We all would have heard about volcanoes. It is caused due to a rupture in the crust of the earth. This rupture allows the hot volcanic lava to flow out from its magma chamber which is situated deep below the crust.

The volcanic eruption involves a process by which lava and gases are expelled through the volcanic vent. According to some findings done by volcanologists, there are different types of eruptions. But in the case of some volcanoes, they only exhibit one type of eruption.

In this article, we are going to discuss volcanic eruptions, how it occurs, and types of volcanic eruptions. We will also get an idea about how it can affect us.

Different Types of Volcanic Eruptions

According to the research done by the volcanologists, there are majorly three types of volcanic eruptions.

Magmatic Eruptions

Phreatomagmatic Eruptions

Phreatic Eruption

Magmatic Eruptions

The occurrence of Magmatic eruption happens when explosive decompression gas releases and causes juvenile clasts. There are five different types of Magmatic eruptions.

Hawaiian Eruption

In this type of eruption, there is an occurrence of an effusive eruption in which fluid basalt type lavas are expelled with low amounts of gaseous content. The intensity of eruption from the Hawaiian eruption is less than half when compared to others. The occurrence of this eruption is not as centralized as other volcanic types.

Strombolian Eruption

This eruption is named after the volcano of Stromboli. Usually, in this eruption, there is an occurrence of gas bubbles bursting out with magma. The bubbles that occur during eruption accumulate the magma and turn into larger bubbles which are known as gas slugs. When these bubbles reach outside and due to the difference between air pressure they get burst with a loud sound of pop.

Vulcanian Eruption

This eruption is named after volcano Vulcano. In this type of volcanic eruption, the viscous magma in the volcano makes it difficult for gases to escape. This difficulty for gases to escape leads to an explosive eruption which is quite different when compared to other eruptions.

Peléan Eruption

This eruption has got its name from Mount Pelee, which is situated in Martinique. The Peléan eruption happened once in 1902 and it was a horrible disaster that happened in history. In this eruption, a large amount of dust, ash, gas and lava fragments were blown out of the volcano's central crater. It usually happens when the andesite lava dome, dacite, and rhyolite collapses and causes large eruptive columns.

Plinian Eruption

In this type of eruption, there are dissolved volatile gases stored in the magma. This gas gets accumulated with magma and produces bubbles. Once these bubbles reach a certain size they explode. The velocity of eruption is controlled by the gas content. The crust surface that has low strength surface rocks, commonly crack under the pressure of the Plinian eruption.

Phreatomagmatic Eruptions

This eruption happens due to the interaction between water and magma. It usually occurs due to thermal contraction. When there is a temperature difference that happens due to the interaction of lava and water, it causes this eruption. There are three types of phreatomagmatic eruptions.

Surtseyan

Submarine

Subglacial

3. Phreatic Eruption

This eruption occurs due to the expansion of steam. It happens when the cold ground or surface water comes in contact with molten rock or magma and gets superheated and explodes. There are some features of a phreatic eruption in which fragments of pre-existing solid rocks blast out through the volcanic conduit. The phreatic eruption can also cause the release of deadly toxic gases that can suffocate anyone within the range of eruption.

Problems Caused by Volcanic Eruption

You can find various types of effects happening during volcanic eruptions like an eruption of high silica lava, effusive eruption of low silica lava (basalt), Pyroclastic flows, Lahars, and various other effects.

1. Volcanic gases

There are differences in the concentration of volcanic gases and it can vary from one volcano to the next one. Usually, water vapour is the most abundant volcanic gas that consists of carbon dioxide and sulfur dioxide. Other volcanic gases are hydrogen sulfide, hydrogen chloride, and hydrogen fluoride.

Sometimes these volcanic gases can be poisonous in nature that can be hazardous to the life of those who live near the volcano.

2. Acid Rain

Acid rain is also one of the main outcomes of a volcanic eruption. It occurs due to complex reactions that take place due to sulfate aerosols that help in altering the chlorine and nitrogen chemical species in the stratosphere.

This increase in stratospheric chlorine level leads to chlorofluorocarbon pollution and generates chlorine monoxide which destroys ozone. Most of this hydrogen chloride (HCl) and hydrogen fluoride (HF) get dissolved in water droplets in the eruption cloud and fall to the ground as acid rain.

Affects the Environment

A volcanic eruption can be dangerous for the environment. The clouds of ashes, dust, and gas coming from the volcanic eruption can cause a reduction in the global temperature by several degrees.

According to research done on volcanic eruption, it is found that the sulphur dioxide emitted from the volcano can cause Acid rain which can be harmful. The pyroclastic material ejected from the volcano can be harmful to the environment.

Some Positive Effects of Volcanic Eruption1. Increase the Fertility of Soil

A volcanic eruption can be also beneficial for the environment. Volcanic soil is known to be very fertile. The volcanic soil is also known as laterite soil. This soil is very fertile as they are very rich in minerals. Some countries like Brazil and Southern Italy have benefited from the volcanic fertile soil.

2. Great for Tourism

There are so many daring tourists who are attracted towards dormant and active volcanoes. These volcanoes are a craze for thousands of tourists. There are some volcanoes that are very popular tourist spots like Mount Vesuvius in southern Italy and Mount Etna in Sicily. Some people also buy Volcano T-Shirts to flaunt them.

3. Great Source of Geothermal Energy

A volcanic eruption is a great source to generate geothermal energy. For example, around 80% of the electricity produced in Iceland is created with the help of geothermal energy. This energy is produced when the water turbines pushed by the water vapour that evaporates come to contact with superheated rocks (over 1000 degrees Celsius). The energy produced by turbines then changes into electricity.

Conclusion

As we know Volcanic eruption is a destructive force but sometimes it can also act as a constructive force for the environment. We are writing this article to explain this force of both constructive and destructive nature. We want you to know about the different types of volcanic eruptions. You can also teach your kids about Volcanoes with a model Volcano.

We have also mentioned its positive and negative effects in this article. The occurrence of volcanic eruptions happens due to nature's will for keeping the natural balance maintained. We should be aware that nature is the supreme power and we should not play against it.

The greatest threat to our planet is the belief that someone else will save it!