Volcanoes form when magma rises up from below the earth's crust and emerges at the surface. A volcano has a vent where magma and molten rock, called lava, escape. The lava accumulates to form a volcanic mountain over time. There are three main types of volcanoes: active volcanoes that frequently erupt like Mount Etna in Italy; dormant volcanoes that were once active but have not erupted recently, though could again, like Mount Vesuvius; and extinct volcanoes that were active in the past but will not erupt again, like Mount Kilimanjaro.

1. VOLCANOES

2. VOLCANO
•Volcano is a vent or opening in the
earth’s crust from which magma or
molten rock materials emerges out.

3. STRUCTURE OF A VOLCANO

4. • Magma:
Molten rock materials found within the
earth’s interior
• Lava:
When the magma reaches the earth’s surface
it loses water vapour, some gases , ash, dust
etc. and then it is called Lava.

5. • Fissure:
Through which the magma comes out
• Vent:
The magma comes out from the aesthenosphere
on to the crust of the earth is known as Vent.

6. • Crater:
The Funnel shaped depression that can be
seen on the summit of a volcanoe.
Volcanic mountain:
The rocks and other materials which come on
to the surface of the earth from the interior of
the earth accumulates to develop volcanic
mountains.

7. World Map of Volcanoes

8. TYPES OF VOLCANOES
Volcanoes
Active Dormant Extinct

9. • Active Volcanoe:
Those that frequently errupt
Eg: Mt. Etna (Italy), Mt. Fujiyama (Japan)
Mt. Etna which recently errupted
in December 2013

10. • Dormant volcanoe
• Those that have errupted earlier and not
active in the recent past, but can become
active.
Eg: Mt. Vesuvius (Italy)
Mt, vesuvius lastly erupted in 1944

11. • Extinct volcanoe
• Active at a time but will not errupt again
Eg: Mt. Kilimanjaro (Africa)
The last major eruption has been dated to
between 150,000 and 200,000 years ago

12. PACIFIC RING OF FIRE