Essay, Paragraph or Speech on “Volcanoes” Complete English Essay, Speech for Class 10, Class 12 and Graduation and other classes.

Volcanoes

Volcano is a natural occurrence that takes place from a mountain with a large opening at the top. Volcanic eruptions have always sat life-threatening situations and death traps for civilizations all over the world. The study of volcanoes is known as ‘volcanology’.

A volcano is an opening in the surface of the earth. This opening allows hot magma, volcanic ash and gases to escape from below the surface. Magma is a very hot liquid rock found below the earth’s surface. When this happens, we say that the volcano has erupted.

When molten rock is below the surface of the earth, it is called ‘magma’. After it erupts from an opening, it is called lava’. Lava is red-hot when it fires out. The rising lava contains crystals, dissolved gases and solid pieces of rocks. Mostly this liquid is made up it oxygen, silicon, aluminium, iron, magnesium, calcium, sodium, potassium and manganese.

When an eruption takes place, it explodes into the air and the molten rock forces its way out. The lava starts flowing, destroying everything that comes in its path. Thick, dark clouds of smoke rise high from the opening and spread in the sky. Even finer dust particles, mud and ash are thrown high into the air. As the lava cools, it slowly becomes solid. Its colour changes into a black, dark grey or even red.

Volcanoes are popularly classified into three categories. They are active volcanoes, dormant volcanoes and extinct volcanoes. Those volcanoes that erupt frequently are called ‘active volcanoes’. Krakatoa is an active volcano in the island in the Sunda Strait between Java and Sumatra in Indonesia. It has erupted several times causing tremendous disasters. The worst of the eruption took place in 1883. Those volcanoes that have erupted in early times but are now quiet are called ‘dormant volcanoes’. They are also called as ‘sleeping volcanoes’. They stay silent for long time and abruptly erupt violently causing massive destruction to life and property. Vesuvius in Italy and Katmai in Alaska are the examples of dormant volcanoes. Information about the eruption of such volcanoes is found in history. Volcanoes that have not erupted for thousands of years are considered as ‘extinct volcanoes’. As they do not show any indication of future eruption, they are also known as ‘dead volcanoes’. Mount Kilimanjaro in Tanzania in the continent of Africa is an example of extinct volcano. By looking at the formation of the rock, geographers can guess that they erupted long ago. However, there is no record of it in history.

Scientists usually, expect a volcanic erupting if the signs of unrest such as earthquakes are seen. The life of a volcano can vary from months to several million years. Many volcanoes have erupted in past few thousand years but are currently not showing any signs of eruption.

( 460 Words )

Volcanoes

A volcano is an opening, in the planet’s surface which allows hot, molten rock, ash and gases to escape from below the surface. The name, “volcano” originates from the name Vulcan, a god of fire in Roman mythology. Volcanoes are like giant safety valves that release the pressure that builds up inside the Earth. The Hawaii islands were formed by 5 volcanoes. Classified by the extent of their activity volcanoes are of four types. An ‘active’ volcano is one that erupts regularly. There are about 500 known active volcanoes on Earth, not counting those that lie beneath the sea. A ‘dormant’ volcano is one that has not erupted for many years, although there is still some activity deep inside it. An ‘extinct’ volcano is one which has ceased to be active.

A volcanic eruption occurs when hot rocks and lava burst from a volcano; and geysers and springs are actually just volcanoes that throw boiling water high in the air. They are caused by volcanic heat warming trapped ground water. The liquid rocks inside a volcano are called magma and when it flows out it is called as lava. Fresh lava has temperatures from 700 degrees C to 1200’C and glows red-hot to white hot as it flows. The most dangerous volcanic eruption recorded is the eruption of Mount St. Helens in Washington. The tallest volcano in the world is the Ojos del Salado, a volcano in Chile. The world’s largest volcano is the Muano Loa in Hawaii.

Volcanoes are generally concentrated on the edge of continents, along the island chain, or beneath the sea forming long mountain ranges. A major part of the world’s active volcanoes above sea level encircle the Pacific Ocean forming the “Ring of Fire.” Volcanoes can have serious effects on the lands and people around them when they erupt. The destruction they leave in their wake accounts for the total annihilation of the surrounding landscape. Around 2,00,000 people have lost their lives to volcanic eruptions in the past five hundred years. Buildings are destroyed, people are rendered homeless, people are killed, plant and animal life are both destroyed and the poisonous gases that emanate from the volcanoes can cause death and diseases like pneumonia in the people who survive it.

However not everything associated with the volcanoes is negative. The crust of the earth exists due to the large volumes of magma that did not erupt but instead cooled below the surface. It results in rich soil which is good for cultivation. The volcanic ash that blows out of the volcano increases soil fertility by adding nutrients to the soil. Ground water heated by magma can be tapped for geothermal energy. Most of the metallic minerals like copper, gold, silver, lead and zinc are mined from the magmas found deep within the roots of extinct volcanoes.

With the increasing studies done by scientists on volcanoes it is becoming possible to gauge the activity level of a volcano. With this information although it might not be possible to prevent the erupting of a volcano at least the massive destruction of lives can be avoided by getting people evacuated in time.

( 600 Words )