Volcanic eruptions

A volcano is an opening or rupture in the earth’s surface that allows magma (hot liquid and semi-liquid rock), volcanic ash and gases to escape. They are generally found where tectonic plates come together or separate but they can also occur in the middle of plates due to volcanic hotspots. 

A volcanic eruption is when lava and gas are released from a volcano—sometimes explosively. The most dangerous type of eruption is called a 'glowing avalanche' which is when freshly erupted magma flows down the sides of a volcano. They can travel quickly and reach temperatures of up to 1,200 degrees Fahrenheit. Other hazards include ash fall, and lahars (mud or debris flows). Volcanoes often cause population displacement and food shortages.

Ongoing volcanic activity around the world is not only about dramatic news on disruptions to daily life. Volcanoes also help provide us with fertile soils and comfortable atmospheric conditions for daily living. 

How Do Volcanoes Erupt?

It is so hot deep within the earth that some rocks slowly melt and turn into a thick flowing matter known as magma. Since it is lighter than solid rock, the magma rises and collects in magma chambers. Eventually, some magma pushes through fissures and vents on the earth’s surface. Hence, a volcanic eruption occurs, and the erupted magma is known as lava.

We need to understand the Earth’s structure to know how volcanoes erupt. At the top lies the lithosphere, the outermost layer that consists of the upper crust and mantle. The thickness of the crust ranges from 10km to 100km in mountainous locations and mainly consists of silicate rock.

We know that the mantle of the Earth is too hot, and the temperature ranges from 1000° Celsius to 3000° Celsius. The rocks present inside melt due to high pressure and temperature. The melted substance is light in weight. This thin lava comes up to the crust since it can float easily.

Volcanoes can be either active, dormant or extinct. While active volcanoes erupt regularly, dormant volcanoes erupted in the past, but do not now; and extinct volcanoes have never erupted and scientists do not expect that they will..