2. What is volcano
• -A volcano is a rupture in the crust of a planetary-mass object, such as
Earth, that allows hot lava, volcanic ash, and gases to escape from a
magma chamber below the surface. On Earth, volcanoes are most often
found where tectonic plates are diverging or converging, and most are
found underwater
• The word ‘volcano’ comes from the island ‘Vulcano’, which is a volcanic
island in Italy. Vulcano, Italy. The island actually gets its name from the
Roman God of fire – Vulcan. Roman mythology says that Vulcan lived in a
volcano.
• According to the United States Geologic Survey, there are approximately
1,500 potentially active volcanoes worldwide. Most are located around the
Pacific Ocean in what is commonly called the Ring of Fire.About 500 of
those 1,500 volcanoes have erupted in historical time.
3. The Three Types of Volcano
• Active volcanoes have a recent history of eruptions; they are likely to
erupt again.
• Dormant volcanoes have not erupted for a very long time but may
erupt at a future time.
• Extinct volcanoes are not expected to erupt in the future.
5. • The Three Classification of Volcanoes
1. Cinder Cone Volcanoes.
• Cinder cones are also
known as ash cones.
Cinder cones are the
type of volcano that is
formed by pyroclastic
fragments like volcanic
ashes, solidified lava
pieces, volcanic clinkers,
pumice and hot gases.
These volcanoes are
formed around the
volcanic vent and are
known to be the simplest
form of a volcano.
6. 2. Shield Volcano
• Shield volcanoes are
one type of volcano.
These volcanoes are
built mainly out of lava
that is very fluid. This
lava flows out, cools and
hardens, adding to
layers of cooled and
hardened lava
underneath it.
7. 2.Composite Volcanoes (Stratovolcanoes)
• Stratovolcanoes have
relatively steep sides
and are more cone-
shaped than shield
volcanoes. They are
formed from viscous,
sticky lava that does
not flow easily. The
lava therefore builds
up around the vent
forming a volcano
with steep sides.
8. History of Mount Tambora
• The most destructive explosion on earth in the past 10,000 years was the
eruption of an obscure volcano in Indonesia called MountTambora. More than
13,000 feet high, Tambora blew up in 1815 and blasted 12 cubic miles of gases,
dust and rock into the atmosphere and onto the island of Sumbawa and the
surrounding area. Rivers of incandescent ash poured down the mountain’s flanks
and burned grasslands and forests. The ground shook, sending tsunamis racing
across the JavaSea. An estimated 10,000 of the island’s inhabitants died instantly.
• It’s the eruption’s far-flung consequences, however, that have most intrigued
scholars and scientists. They have studied how debris from the volcano shrouded
and chilled parts of the planet for many months, contributing to crop failure and
famine in North America and epidemics in Europe. Climate experts believe that
Tambora was partly responsible for the unseasonable chill that afflicted much of
the Northern Hemisphere in 1816, known as the “year without a summer.”
Tamboran gloom may have even played a part in the creation of one of the 19th
century’s most enduring fictional characters, Dr. Frankenstein’s monster.
