Effect Of Volcanism

Introduction

When a volcano erupts, it discharges molten rock (lava), gases, rock fragments, ash and other volcanic matter onto the land’s surface. The phenomenon of the discharge of the items mentioned above onto the land’s surface is known as ‘Volcanism.’ Volcanism has destructive as well as constructive effects.

Constructive effects

Fertile soil: During volcanism, ash is emitted from the volcanoes onto the Earth’s surface near the eruption site. Depending on the volcano and the kind of Magma that was dispersed, the ash contains different soil nutrients. The most commonly found nutrients are Silica and Oxygen. This ash ends up working as a fertiliser for the soil and enriches it. Volcanism also leads to the emission of certain volcanic rocks onto the Earth’s surface. These rocks are usually rich in Magnesium, Potassium and Iron, further enriching the fertility of the soil.

Contact Metamorphism: Metamorphism in geology refers to the change in the structure of a body of rock from which it had initially been formed. When Magma, emitted as a result of volcanism, comes into contact with an existing body of rocks, it increases the temperature of those rocks. This leads to them being infiltrated with the fluid from Magma. This phenomenon is known as contact metamorphism. It gives rise to rocks such as Marbles, Hornfels, etc.

Land formation: A volcanic eruption through volcanism leads to new materials being pushed onto the Earth’s surface. This gives rise to new landforms. For example, repeated volcanic eruptions over the same spot gave birth to the Hawaiian Islands. Many other islands, such as the Aleutian Islands, the Mariana Islands, the Ryukyu Islands, etc., were all formed after volcanic eruptions.

Emission of gases: When volcanism occurs, many gases are emitted. One of the most important amongst them is sulphur dioxide. Once in the stratosphere, this gas turns into sulphuric acid aerosols. An aerosol is a discharge of fine particles in the atmosphere, such as fog, where the fine particles are essentially water. These aerosols quickly cover the atmosphere and stay in it for years at length. This gives rise to a cooling effect and brings the temperature down.

Volcanic lakes: Due to significant volcanic eruptions, sometimes a large crater is formed on the Earth’s surface. Once the volcano is inactive, these craters are often filled with water. This may occur through rain or groundwater circulation, or any other method. These are commonly known as crater lakes.

Destructive effects

Earthquakes: The movement of Magma, that lies beneath the surface of a volcano, can often lead to earthquakes. During a volcanic eruption, the Magma starts moving towards cracks in the Earth so that the material inside the volcano can be dispersed onto the land’s surface. This movement can lead to large earthquakes. This makes the area surrounding volcanoes extremely volatile to live in and puts people’s lives near the eruption site at considerable risk. The earthquakes can cause large cracks in the ground, leading to large-scale loss of life and significant damage to property.

Effects on climate: Volcanic eruptions have drastic effects on the planet’s climate due to the eruption of gases that occur during volcanism. The gases once in the atmosphere greatly influence the planet and lead to unpredictable weather conditions.

Pyroclastic Flows: When a volcanic eruption occurs, it often gives rise to clouds of hot gas known as ‘pyroclastic flows’. It consists of small volcanic rocks, debris, etc. They travel at extremely high speed and are of exceptionally high temperature. Any person caught in them or that comes in contact with them is instantly killed.

Volcanic Ash: Volcanic Ash contains many tiny fragments of Rocks and Minerals and often also contain volcanic glass. These are extremely harmful to human and animal life if breathed in.

Conclusion

Volcanism refers to the process by which a volcano erupts and emits substances onto the Earth’s surface. It is a significant geological phenomenon with enormous positive and negative impacts. A volcanic eruption in its wake leads to large-scale destruction of property and loss of life. It takes several years for its effects to subside and for life to go back to normal for the people living near the eruption site. Furthermore, it gives rise to large-scale earthquakes, pyroclastic flows, and many aerosols that are harmful to humans. However, over the years, volcanic eruptions have positively affected the planet by creating new landforms, giving rise to more fertile soils, creating new lakes, etc. Hence, while volcanoes seem extremely destructive at first, in reality, they also have a lot of positive and beneficial effects on the planet.