Page 252 - New Medley 5 Semester 2

VOLCANOES

e word volcano comes from the name Vulcan, the

Roman God of Fire. A volcano is an opening on the
earth’s surface which allows hot, molten rocks, ash

and gases to escape from below the surface. ese
burst out of the crust through a vertical tunnel called

vent. e hot molten rocks that come out on the

ground is called lava. e lava spreads over the land Volcano
sometimes covering an entire region. When lava is
below the earth’s surface, it is called magma. Some
volcanoes are formed under the sea. When the lava

cools down, the area so formed looks like a new island.

Based on the nature of eruption, volcanoes can be
active, dormant or extinct.
Hot lava flowing on the ground
 Volcanoes that have erupted in recent years
and may erupt again any time are called active

volcanoes. Many active volcanoes can be found

in the Paci c area. Famous active volcanoes are
Mount Vesuvius, Mount Etna, Mount Erebus and
Mount Fuji. e Barren Island is the only active

volcano in the Indian subcontinent in Andaman
and Nicobar Islands. Barren Island volcano in
Andaman Islands
 Volcanoes that have not erupted in recent years but may erupt in the future
are called dormant volcanoes.

 Volcanoes which have stopped erupting permanently are called extinct

volcanoes.

TSUNAMI

Tsunami (pronounced as su-nami) waves are also

known as tidal waves or storm waves. A tsunami
is caused by an undersea earthquake or by a severe

hurricane or cyclone. ese waves from the sea come

rolling towards the shore. ey cause destruction on

the seashore within seconds. Tsunami

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