Volcano

1.  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

2.  Volcanoes are formed when magma from within the Earth's upper mantle works its way to the surface. Reporter: Mylene S.Pilongo

3. Reporter: Mylene S.Pilongo

4. 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.

7. 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

8. 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 Reporter: Mylene S.Pilongo

9. 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

10. 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

11. 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.

12. 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.

13. 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.

14. 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.

15. 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.

16. • 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) Reporter: Mylene S.Pilongo

18. 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)

20. 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

21. Spectacular eruption from the Puyehue volcano in Chile. Reporter: Mylene S.Pilongo

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

24. The “gentle” flow of a shield volcano in Hawaii . Reporter: Mylene S.Pilongo

25. Reporter: Mylene S.Pilongo Lava tunnel in Madeira, Portugal.

26. Characteristics: it erupts at least 1,000 km3 of material (a large volcano erupts around 1 km3) it forms a depression, called a caldera Reporter: Mylene S.Pilongo

27. Thestagesinthecreationofasupervolcanocaldera: Reporter: Mylene S.Pilongo Magma cannot escape to the surface and collects under the lower crust.

28. Reporter: Mylene S.Pilongo An 'uplifted bulge' begins to form under the lower crust as the magma chamber enlarges. Thestagesinthecreationofasupervolcanocaldera:

29. Reporter: Mylene S.Pilongo Cracks appear on the surface. Gas and ash erupt from the magma chamber through these cracks. Thestagesinthecreationofasupervolcanocaldera:

30. Reporter: Mylene S.Pilongo The magma chamber collapses and a depression is formed. This is called a caldera. Thestagesinthecreationofasupervolcanocaldera:

31. 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

32. 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.

34. • 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

35. • 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