GEOLOGY

Detailed explanation-1: -Main Vent: A volcano’s main vent is the weak point in the Earth’s crust where hot magma has been able to rise from the magma chamber and reach the surface.

Detailed explanation-2: -Magma that has erupted is called lava. Some volcanic eruptions are explosive and others are not. The explosivity of an eruption depends on the composition of the magma. If magma is thin and runny, gases can escape easily from it.

Detailed explanation-3: -When the magma reaches the surface of the Earth it is then called lava. The lava leaving the side vent causes the volcano to add a layer of lava and usually a layer of ash with each eruption. These eruptions build the volcano higher and wider.