Question

How does volcano form and erupt?

Answer 1

magma is sometimes pushed up toward the surface, notably during volcanic eruptions. As it cools, the magma solidifies in the form of magmatic rocks such as basalt. So the rocks of Earth's crust are constantly being transformed as part of the geological cycle that lasts millions of years.

Answer 2

Formed-
Volcanoes are formed when magma from within the Earth's upper mantle works its way to the surface. At the surface, it erupts to form lava flows and ash deposits. Over time as the volcano continues to erupt, it will get bigger and bigger.

Erupts-
When it's underneath the surface, the molten rock is called magma. When it reaches the surface, it erupts as lava, ash and volcanic rocks. With each eruption, rocks, lava and ash build up around the volcanic vent where the material blasts out of.