Volcanoes form when magma rises from the Earth's mantle and upper mantle and erupts from a vent on the Earth's surface. There are several types of volcanoes that differ in shape and composition based on the type of boundary they are located at and the viscosity of the lava they emit. The largest volcanoes are called supervolcanoes and have the potential to cause catastrophic global consequences when they erupt due to the massive amounts of material they can eject.
Z Score,T Score, Percential Rank and Box Plot Graph
Volcano
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4. 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
5.
6. Volcanoes are
formed when
magma from
within the
Earth's upper
mantle works
its way to the
surface.
Reporter: Mylene S.Pilongo
8. Reporter: Mylene S.Pilongo
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.
11. 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.
Reporter: Mylene S.Pilongo
12. 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
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13. 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.
Reporter: Mylene S.Pilongo
14. Reporter: Mylene S.Pilongo
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
15. Reporter: Mylene S.Pilongo
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.
16. Reporter: Mylene S.Pilongo
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.
17. Reporter: Mylene S.Pilongo
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.
18. Reporter: Mylene S.Pilongo
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.
19. Reporter: Mylene S.Pilongo
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.
22. 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.
Reporter: Mylene S.Pilongo
(Composite Volcano)
24. 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.
Reporter: Mylene S.Pilongo
26. Characteristics:
Shield volcanoes are usually found
at constructive or tensional
boundaries.
They are low, with gently sloping sides.
Reporter: Mylene S.Pilongo
30. Characteristics:
it erupts at least 1,000 km3 of material (a
large volcano erupts around 1 km3)
it forms a depression, called a caldera
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32. Reporter: Mylene S.Pilongo
An 'uplifted bulge' begins to form under the lower
crust as the magma chamber enlarges.
Thestagesinthecreationofasupervolcanocaldera:
33. Reporter: Mylene S.Pilongo
Cracks appear on the surface. Gas and ash erupt
from the magma chamber through these cracks.
Thestagesinthecreationofasupervolcanocaldera:
34. Reporter: Mylene S.Pilongo
The magma chamber collapses and a
depression is formed. This is called a caldera.
Thestagesinthecreationofasupervolcanocaldera:
35. 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.
Reporter: Mylene S.Pilongo
36. Reporter: Mylene S.Pilongo
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.
38. • 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.
Reporter: Mylene S.Pilongo
39. • 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.
Reporter: Mylene S.Pilongo
We will be talking about the hottest and yet coolest thing on the face of the Earth.
Pool of magma – magma chamber
Magma – molten rocks
We learned that the surface of our planet is not one big piece – it is broken into what we call as tectonic plates which fit together like a jigsaw puzzle. These tectonic plates “float” on a hotter, softer layer in the Earth’s mantle. When that very hot and viscous layer comes up towards the surface, we call it “magma”.
Volcanoes on Earth are generally located in areas where the tectonic plates diverge (split) or converge (compress) with each other. Usually happened in the plate boundaries.
1. The magma rises up to fill in the space. When this happens underwater volcanoes can form.
2. When this happens, part of Earth's crust can be forced deep into its interior. The high heat and pressure cause the crust to melt and rise as magma.
3. areas where underlying mantle is extremely hot, much hotter than in other areas. These areas heat up magma. The magma becomes less dense. When it is less dense it rises.
The stages of volcano is classified into 3:
An active volcano is one which has recently erupted and there is a possibility that it may erupt soon.
A dormant volcano is one which has not erupted in a long time but there is a possibility it can erupt in the future.
An extinct volcano is one which has erupted thousands of years ago and there’s no possibility of eruption.
The characteristics of a volcano differs base on its type
When most people think about a volcano, they just imagine a conical mountain with ash and/or lava going out from its mouth. But that’s just one type of volcano – the stratovolcano (or composite volcano).
Alternating layers (strata)
destructive or compressional boundaries – boundary of 2 plates which are moving toward each other
The eruptions from these volcanoes may be a pyroclastic flow rather than a lava flow. A pyroclastic flow is a mixture of hot steam, ash, rock and dust.
A pyroclastic flow can roll down the sides of a volcano at very high speeds and with temperatures of over 400°C.
constructive or tensional boundaries – areas between 2 crustal plates that are moving away from each other
They are formed by eruptions of thin, runny lava.
Eruptions tend to be frequent but relatively gentle.
Caldera – a cauldron / depression shaped tectonic feature usually formed from the collapsed of a magma chamber
a supervolcano often has a ridge of higher land around it
a supervolcano erupts less frequently - eruptions are hundreds of thousands of years apart
Pyroclastic flow These awesome features are heavier-than-air emulsions that move much like a snow avalanche, except that they are fiercely hot, contain toxic gases, and move at phenomenal, hurricane-force speeds.
Lahar is very dangerous because it's consistency and the way it acts is very much like cement.
Pumice - all types of magma (basalt, andesite, dacite, and rhyolite) will form pumice.