Volcanoes form when magma rises up through the crust via a vent or fissure. There are three types of volcanoes: active volcanoes have erupted recently and could erupt again soon, dormant volcanoes have not erupted in a long time but could still erupt, and extinct volcanoes erupted thousands of years ago with no possibility of future eruptions. Volcano formation occurs as tectonic plates move around on the semi-fluid asthenosphere, causing magma to rise up at the boundaries where plates meet.

2. • Definition of volcanoes
• Formation of volcanoes:
• Stages of volcanoes
• Steps of formation

3. Volcano is a mountain that opens downward
to a pool of molten rock below the surface of
the earth. When pressure builds up, eruptions
occur. Gases and rock shoot up through the
opening and spill over or fill the air with lava
fragments. mudflows and rockfalls.

4. Stages of volcanoes:
Scientists have categorized volcanoes into
three main categories: active, dormant and
extinct.
• Active volcano: is one which has recently
erupted and there is a possibility that it may
erupt soon.

5. • Dormant volcano: is one which has not
erupted in a long time but there is a
possibility it can erupt in the future.
• Extinct volcano: is one which has erupted
thousands of years ago and there’s no
possibility of eruption.

6. Steps of formation:
Volcano is formed when magma, present in the
Earth's interior, manages to rise up to the
surface via a vent or a fissure. Hot ash and
gases also escape from the interior of the Earth,
along with magma. While the gases get thrown
into the air, the magma and ash cool down
forming distinctive volcanic landforms.

7. To understand in detail, the process of formation of
volcanoes, one has to understand what lies beneath
the surface of the Earth.
• The Earth is essentially
made up of five different
layers viz., the solid inner
core, the liquid outer core,
the liquid inner mantle, the
upper mantle, and the crust.

8. • The upper mantle comprises two distinct
layers. The lower layer is the asthenosphere,
which is semi-fluid in form, and the upper
layer is that of the uppermost mantle, a.k.a
rigid mantle, which is a solid layer of rock,
just below the Earth's crust.
• The Earth's crust and the uppermost solid
mantle together form the lithosphere.

9. • The Earth's lithosphere is like a huge
jigsaw puzzle, with pieces of different
shapes and sizes fitting into each other
perfectly. These pieces are known as
tectonic plates.

10. • The lithosphere (and hence the tectonic
plates) rests on the asthenosphere (the
lower layer of the upper mantle), which is
the center of most volcanic activity that
takesplace underneath the Earth.The
asthenosphere is highly vicious and
ductile.

11. • Since the asthenosphere is semi-fluid, it is
obviously not stationery. Hence, the
tectonic plates that rest on it are always in
motion. However, this motion is too slow
to be perceived by human senses.

12. • The tectonic plates display three kinds of
movements. They either move towards
each other (convergent boundaries) or
away from each other (divergent
boundaries) or just slide past each other
(transform boundaries) in a horizontal
manner.