Volcanoes

A volcano is a type of geophysical phenomenon that occurs when magma, gas, and pressure builds-up at the bottom of the earth’s surface and ultimately gets erupted on the surface of the earth. There will be a discussion on the formation of volcanoes and then explanation of different stages of volcanoes. In addition, it also includes the types of volcanoes that occur in the environment. By the end of the article, a comprehensive knowledge about reasons for the formation of volcanoes can be assessed.

Volcano 

A volcano forms at the edges of the tectonic plates that are present below the surface of the earth. It is a naturally occurring geophysical phenomenon that happens when molten rock particles and gases tend to escape from an aperture on the surface of earth. The formation of volcanoes primarily occurs at the boundaries between the tectonic plates. At present most of the active volcanoes are found along a belt called the “ring of fire” which is near the Pacific Ocean. This volcanic eruption occurs mainly in the form of magma, which is generated in the outermost layer of the earth as well as at varying depths in the upper mantle. 

Formation of volcano 

The volcano formation occurs in one of the three ways such as magma that originates in the hot spots, magma that originates in rift zone or subduction zone where one tectonic plate goes on the top of the other tectonic plate. The formation of a volcano occurs when water from the ocean or above ground finds a path and flows through the subduction zone and gets in touch with the mantle. Therefore, the liquids reacts with the mantle and this causes the melting of the hot solid rocks to form magma. Then the superheated magma gets evaporated and becomes the steam that is trapped inside. The more water flows into the volcano, the more steam is generated, which creates huge pressure inside the earth layers, and eventually, it comes out in the form of a volcano.

Different stages of volcano 

There are mainly three different stages of a volcano Active, Dormant and Extinct. 

• Active volcano: A volcano is active when it is erupting in current times or likely to erupt soon or has had at least one eruption in the past 1000 years. For example, “Kilauea volcano in Hawaii” is one of the most active volcanoes in the world followed by “Piton de la Fournaise on La Réunion Island” and “Etna in Italy”
• Dormant volcano: This type of volcano can be called a sleeping volcano, where an active volcano is supposed to erupt soon but at present, they are not erupting. Some examples of dormant volcanoes are Tanzania, Mount Fuji in Japan, Mount Kilimanjaro, and Africa 
• Extinct volcano: This type of volcano is one that has not erupted in past 10,000 years or will never erupt again. For example, “The tallest mountain in the United Kingdom Ben Nevis, in the northern Pacific Ocean Hawaiian–Emperor seamount chain, and the Philippine Sea Kyushu-Palau Ridge

Types of volcanoes

There are many types of volcanoes present but among them mainly three types of volcanoes are considered, that are cinder cones, composite volcanoes, and shield volcanoes. 

• Cinder volcano: This type of volcano is also called spatters cones that are typically less than 200 meters high and have straight sides. This type of volcano is made up of loose fragments of Scoria which is a vesicular rock from the basaltic lava and they have very little strength. Therefore, they can easily and quickly erode
• Composite volcano: The concerned type of volcano is also known as a strato volcano and they are composed of layers of lava alternating with layers of tephra. The mentioned type of volcano typically erupts rhyolitic and has higher viscosity siliceous lava. This type of lava does not travel much from the vent as blastic lava does
• Shield volcano: This type of volcano has a gentle hill-like shape and they are composed of the successive flow of low viscosity basaltic lava. Due to the low viscosity of lava, it can flow a long distance which results in the greater size of the volcano

Conclusion 

The discussion on the naturally occurring geophysical phenomenon that is a volcano is analysed. It can be concluded that plate tectonics play an important role in the formation of volcanoes. In addition, magma is one of the main components generated from the outermost layers of the earth’s mantle, and when it comes out it becomes lava. On the other hand, there are different stages of a volcano such as active, dormant, and extinct.