All about Volcanoes

Formation of a Volcano
Types of Volcanic Eruption
Types of Volcano

1. VOLCANOES Prepared by: Jasmine Nikki M. Versoza

2. What is a volcano? A volcano is a rupture on the crust of a planetary mass object, such as the Earth, which allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.

3. How was a volcano formed? Volcanoes are formed when two tectonic plates push together and the magma from the mantle reaches the surface then it makes a volcano.

4. Formation of a Volcano A crack beneath the earth’s crust extends to the surface and widens. A billowing cloud of smoke escapes out of small hole called vent.

5. Hot molten rock spew out of the vent. This phenomenon is a usually accompanied by ground shaking. The moving molten rock called magma , reach the earth’s surface and flow out as lava. The lava cools, becomes solid, and accumulates in the surrounding area. A low-elevated landform called cone develops. Formation of a Volcano

6. A mounting structure forms around the cone. The accumulating molten rocks may rise to hundreds of meters above the ground. Then a volcano was born. Formation of a Volcano

7. Classification of Volcanoes by Activity Extinct Volcano Dormant Volcano Inactive Volcano Active Volcano

8. Extinct Volcano One that is not erupting and is not likely to erupt in the future.

9. Mount Kilimanjaro Tanzania http://www.volcanolive.com/extinct.html Kilimanjaro has three volcanic cones, Mawenzi , Shira and Kibo

10. Dormant Volcano It is also called a “ sleeping volcano ” It is presently inactive but has erupted within historic time and is likely to do so in the future.

11. Mount Rainier Last Eruption: 1894 ( Southeast of Seattle, Washington, in the United States) http://simple.wikipedia.org/wiki/Mount_Rainier

12. Active Volcano It erupts regularly The eruption is usually quiet but sometimes becomes violent.

13. Types of Volcanic Eruptions Plinian Eruption Pelean Eruption Vulcanian Eruption Strombolian Eruption Hawaiin Eruption

14. Plinian Eruption Eruptions with a high rate of magma discharge, sustained for minutes to hours. They form a tall, convective eruption column of a mixture of gas and rock particles, and can cause wide dispersion of ash.

15. Pelean Eruption It is characterized by the formation of domes around the vents and nucees ardents (ash flows) usually go with the dome formation. It is named after the eruption of the Mount Pelee on Martinique Island, West Indies in 1902.

16. Vulcanian Eruption Includes small to moderate explosive eruptions, lasting seconds to minutes. Ash columns can be up to 20 km in height, and lava blocks and bombs may be ejected from the vent.

17. Strombolian Eruption It is named after a volcano on the Lipari Islands in the Mediterranean. Strombolian eruptions have explosions causing a shower of lava fragments . It gives rise to cinder cones, also called scoria cones.

18. The least violent type of eruption where extremely fluid lava flows quietly from rift or fractures an gradually forms large, smoothly sloping shield volcano . Hawaiian eruptions have fire fountains and lava flows Hawaiian Eruption

19. Kinds of Volcanoes Shield Volcanoes Cinder Cones Composite Volcanoes

20. Shield Volcanoes They are formed when fluid magma erupts quietly and flows from a vent to gradually build up low, broad mountain with gentle slopes. Ex. Mauna Loa in Hawaii

21. Shield Volcano: Mauna Loa in Hawaii

22. Cinder Cones A cone-shaped, steep-sided mountain is formed. They usually consists of volcanic fragments (tephra) that erupts from a vent and accumulate around it. Ex. Paricutin in Mexico

23. Cinder Cones: Paricutin in Mexico

24. Composite Volcanoes It is also known as stratovolcano It is formed when erupted lava and tephra pile up in alternate layers around the vent, forming a steep-sided, towering volcanic cones. Ex. Japan’s Mt. Fuji and Mayon Volcano

25. Composite Volcanoes: Japan’s Mt. Fuji

26. Composite Volcanoes: Mayon Volcano

27. Where are volcanoes mostly found?

28. Volcanoes in the Philippines

29. http://www.philippines.hvu.nl/volcanoes1.htm There are abou t 300 volcanoes in the Philippines, of which 22 are still active volcanoes .

30. Five Most Active Volcanoes In The World

31. 1. Eyjafjallajökull , Iceland

32. 2. Mount Vesuvius, Italy

33. 3. Sakurajima , Japan

34. 4. Mount Merapi , Indonesia

35. 5. Mount Nyiragongo , D.R of Congo http://10mosttoday.com/10-most-active-volcanoes-in-the-world/

36. References: Work Text in Earth Science http://ryanscienceblog.blogspot.com/2011_10_01_archive.html en.wikipedia.org/wiki http://geology.com/volcanoes/types-of-volcanic-eruptions/ https://leakuhta.wordpress.com/category/geology/