Volcano

 A volcano is a mountain that extends down
to a pool of magma between
the crust and mantle.
 It's basically a hole in the Earth from
which magma can erupt.
 The word volcano is derived from the name
of Vulcano, a volcanic island in the Aeolian
Islands of Italy whose name in turn comes
from Vulcan, the god of fire in Roman
mythology.
Reporter: Mylene S.Pilongo

 Volcanoes are
formed when
magma from
within the
Earth's upper
mantle works
its way to the
surface.

 Magma can rise when pieces of Earth's crust called
tectonic plates slowly move away from each other.
 Magma also rises when these tectonic plates move toward
each other.
 A final way that magma rises is over hot spots. Hot spots
are exactly what they sound like--hot areas inside of Earth.

Mount Pinatubo, Philippines is an active stratovolcano in the Cabusilan
Mountains on the island of Luzon, near the tripoint of the Philippine
provinces of Zambales, Tarlac, and Pampanga.

Taal Volcano, Philippines – The second most active volcano in the Philippines
with 33 historical eruptions. All of these eruptions are concentrated on Volcano
Island, an island near the middle of Taal Lake. Taal Volcano and Lake presents
one of the most picturesque and attractive views in the Philippines

Mayon Volcano, Philippines - An active volcano in the province of Albay, on the
island of Luzon in the Philippines. Renowned as the "perfect cone" because of its
almost symmetric conical shape, the mountain and its surrounding landscape was
declared a national park on July 20, 1938, the first in the country.

Mauna Loa, Hawaii – One of five volcanoes that form the Island of Hawaii and
the largest on Earth in terms of volume and area covered. The Hawaiian name
“Mauna Loa” means “Long Mountain”. Lava eruptions from Mauna Loa are very
fluid; eruptions tend to be non-explosive and the volcano has relatively shallow
slopes

Mount Nyiragongo, D.R of Congo – An active volcano located inside Virunga National
Park, in the Democratic Republic of the Congo. The main crater is about two km wide and
usually contains a lava lake. Nyiragongo’s lava lake has at times been the most voluminous
known lava lake in recent history. Nyiragongo and nearby Nyamuragira are together
responsible for 40% of Africa’s historical volcanic eruptions.

Mount Vesuvius, Italy – Located just 9 km (5.6 mi) east of Naples, making it the most
densely populated volcanic region in the entire world. Mount Vesuvius has a history of
activity that makes it one of the world’s most dangerous volcanoes. It last erupted was in
1944, but the most memorable eruption was the massive eruption of 79 AD, when it buried
the cities of Herculaneum and Pompeii.

Mauna Kea, Hawaii - one of the five volcanoes that make up the Big Island of
Hawaii. The peak of Mauna Kea is 4,207 meters above sea level, but 10,203
meters above the base of the floor of the Pacific Ocean.

Mount Ararat, Turkey - Its biggest claim to fame is that it's the biblical site
where Noah's Ark came to rest. But it's also a major volcano—at just under
17,000 feet, the tallest in Turkey. Mount Ararat has erupted once within the last
10,000 years, in 1840.

Mount Fuji, Japan - Rises almost 20,000 feet from a flat plain. It's one of the most famous
volcanoes in the world, along with a few others, like Vesuvius in Italy. Fuji, however, has had
no eruptions on the scale of Vesuvius' in 79 CE, which buried the nearby towns of Pompeii
and Herculaneum, and killed about 16,000 people. Fuji has been dormant since 1707, and
no one died in that eruption.

• Mount Kilimanjaro (Tanzania, Africa)
• Hawaiian–Emperor seamount
chain (Northern Pacific Ocean)
• Mount Kulal (Kenya, Africa)
• Huascarán (Peru)
• Kyushu-Palau Ridge (Philippine Sea)
• Mount Buninyong (Australia)

Characteristics:
 Composite volcanoes are made up of
alternating layers of lava and ash (other
volcanoes just consist of lava).
 They are usually found at destructive or
compressional boundaries.
(Composite Volcano)

Plumes of steam, gas, and ash often occurred at Mount St. Helens, a
stratovolcano, in the early 1980s. On clear days they could be seen from
Portland, Oregon, 50 mi (80 km) to the south. The plume photographed here
rose nearly 3,000 ft (910 m) above the volcano’s rim.

Spectacular eruption from the Puyehue volcano in Chile.

Characteristics:
Shield volcanoes are usually found
at constructive or tensional
boundaries.
They are low, with gently sloping sides.

The “gentle” flow of a shield volcano in Hawaii .

Lava tunnel in Madeira, Portugal.

Characteristics:
it erupts at least 1,000 km3 of material (a
large volcano erupts around 1 km3)
it forms a depression, called a caldera

Thestagesinthecreationofasupervolcanocaldera:
Magma cannot escape to the surface and collects
under the lower crust.

An 'uplifted bulge' begins to form under the lower
crust as the magma chamber enlarges.

Cracks appear on the surface. Gas and ash erupt
from the magma chamber through these cracks.

The magma chamber collapses and a
depression is formed. This is called a caldera.

Yellowstone is one example of a supervolcano. Three huge eruptions
have happened in the last 3 million years. the last eruption was 630,000
years ago, and was 1,000 times bigger than the Mount St Helens eruption
in 1980. The large volume of material from the last Yellowstone eruption
caused the ground to collapse, creating a depression called a caldera.
The caldera is 55 km by 80 km wide.

The supervolcano at Yellowstone is formed because of a volcanic hotspot.
Every year millions of visitors come to see the related features, such
as geysers and hot springs. Old Faithful is one example of a geyser.

• Magma is liquid rock inside a volcano.
• Lava is liquid rock (magma) that flows out of a
volcano. Fresh lava glows red hot to white hot as
it flows.
• Pyroclastic flow is a fluidized mixture of solid to
semi-solid fragments and hot, expanding gases
that flows down the sides of a volcano. This is the
most deadly of all volcanic phenomena.

• Lahar is a type of mudflow or debris flow composed
of pyroclastic material, rocky debris, and water. It is
liquid when it's moving, but when it stops, it
solidifies.
• Pumice is a light, porous volcanic rock that forms
during explosive eruptions. It resembles a sponge
because it consists of a network of gas bubbles
frozen amidst fragile volcanic glass and minerals.

Volcano

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