1. Group PRESENTATION
CREATED BY -:
 R.M.SANDUNI WATHSALA
RAMANAYAKE
 CHAMINI ISURIKA RAJENDRA
 THAKSHILA SEWWANDI
 GRADE 10
 HOLY FAMILY BALIKA
VIDYALAYA
 WENNAPPUWA
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2. Flash Point of Mother Earth...,
VOLCANOES
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3. OUT LINE…..
 What Is A Volcano…………?
 Why They Are Created……...?
 Peep into a Volcano……….
 World Map Of Volcanoes….
 Types Of Volcanoes
 World Most Active Volcanoes…
 Results Of Volcanoes………
 Unforgettable.........
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4. What is a Volcano?
Volcano is named after the Roman god of fire,
Vulcan. A volcano is a vent on the crust of the
Earth, through which hot and molten rock (also
known as lava or magma) comes out.
A volcanic eruption occurs when the pressure
created by the currents of
movement of tectonic plates,
reaches a point where it
needs to be released.
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5. WHY ARE THEY
CREATED?
World is created on plates which are flooring on
magma layer. Magma is in its’ flashpoint and
gives a great pressure. This pressure comes out
through weak points on the earth.
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6. Peep into A VOLCANO….
Magma has a highest
pressure from the inside
of the earth. They come
outside through vents.
The peak of volcano is
called cater . Ashe and
magma creates layers on
the volcano and magma
spread all over the area
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through cones.

7. World Map of Volcanoes
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8. TYPES OF VOLCANOES
 Composite Volcanoes
 Dome volcanoes
 Shield volcanoes
 Cinder Volcanoes
 Stratovolcanoes
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9. COMPOSITE VOLCANO
A composite volcano is a
tall, conical volcano built up
by many layers of hardened
lava, which solidify when
they cool. The volcano
grows taller each time it
erupts and is covered with
fresh lava.
Ex-:
Fuji- Japan , Vesuvius-Italy, St. Helens-USA
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10. Dome Volcano
A dome volcano is small and
often forms inside the caldera
of a stratovolcano. After a large
eruption when large amount of
magma has emptied out of the
magma chamber the summit of
the composite volcano
collapses forming a depression.
Inside the depression magma oozes out to begin
forming a small lava dome.
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11. Shield VOLCANO
Shield volcanoes are large
volcanoes that are built
almost entirely of fluid lava
flows. It has broad sloping
sides and is usually
surrounded by gently sloping
hills in a circular or fan
shaped pattern, that looks
like a warrior's shield.
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12. CINDER CONE
This is the simplest type
of volcano. They are
built from particles and
blobs of congealed lava
ejected from a single
vent.
Most cinder cones have a bowl-shaped crater at the
summit and rarely rise more than a thousand feet or
so above their surroundings.
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13. Stratovolcano
Stratovolcanoes have steep
sides with cones that stick out
like huge bumps. They are built
up when eruptions
of viscous lava, tephra, and
pyroclastic flows happen.
It takes thousands of years for the pressure to
build up enough in stratovolcanoes to cause an
eruption. 13

14. World Most Active
Volcanoes
Volcano Name Location Continuous Eruptions
Etna Italy 3500 years
Stromboli Italy 2000 years
Yasur Vanuatu 800 years
Ambrym Vanuatu 1935-
Tinakula Solomon Islands 1951?-
Erta Ale Ethiopia 1967-
Manam Papua New Guinea 1974-
Langila Papua New Guinea 1960-
Bagana Papua New Guinea 1972-
Semeru Indonesia 1967-
Merapi Indonesia 1967-
Dukono Indonesia 1933-
Sakura-jima Japan 1955-
Suwanose-jima Japan 1949-
Santa Maria Guatemala 1922-
Pacaya Guatemala 1965-
Arenal Costa Rica 1968-
Sangay Ecuador 1934-
Erebus Antarctica 1972-
Piton de la Fournaise Reunion 1920-
Kilauea Hawaii 1983-
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15. EFECTS OF VOLCANOES
NEGATIVE
 Ash fall
 Volcano gas
 Lahara
 Land slides
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16. EFECTS OF VOLCANOES
POSITIVE
 Nutrients to soil
 Natural beauty
landscapes
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17. The Destruction of Pompeii,
79 AD
On August 24, 79 Mount Vesuvius
literally blew its top, spewing tons
of molten ash, pumice and
sulfuric gas miles into the atmosphere. A
"firestorm" of poisonous vapors engulfed the
surrounding area suffocating the inhabitants of the
neighboring Roman resort cities of Pompeii,
Herculaneum and Stabiae. Tons of falling debris
filled the streets until nothing remained to be seen
of the once thriving communities.
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18. The cities remained buried and
undiscovered for almost 1700
years until excavation began in
1748. These excavations
continue today and provide
insight into life during the
Roman Empire.
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19. REFERENCES
 National Geographic Magazine
 Time Magazine
 Wikipedia.com
 Blog Sites
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