1. Group PRESENTATIONCREATED BY -: R.M.SANDUNI WATHSALA RAMANAYAKE CHAMINI ISURIKA RAJENDRA THAKSHILA SEWWANDI GRADE 10 HOLY FAMILY BALIKA VIDYALAYA WENNAPPUWA 1

2. Flash Point of Mother Earth..., VOLCANOES 2

3. OUT LINE.. What Is A Volcano? Why They Are Created...? Peep into a Volcano. World Map Of Volcanoes. Types Of Volcanoes World Most Active Volcanoes Results Of Volcanoes Unforgettable......... 3

4. What is a Volcano?Volcano is named after the Roman god of fire,Vulcan. A volcano is a vent on the crust of theEarth, through which hot and molten rock (alsoknown as lava or magma) comes out.A volcanic eruption occurs when the pressurecreated by the currents ofmovement of tectonic plates, reaches a point where itneeds to be released. 4

5. WHY ARE THEY CREATED?World is created on plates which are flooring onmagma layer. Magma is in its flashpoint andgives a great pressure. This pressure comes outthrough weak points on the earth. 5

6. Peep into A VOLCANO. Magma has a highest pressure from the inside of the earth. They come outside through vents. The peak of volcano is called cater . Ashe and magma creates layers on the volcano and magma spread all over the area 6 through cones.

7. World Map of Volcanoes 7

8. TYPES OF VOLCANOES Composite Volcanoes Dome volcanoes Shield volcanoes Cinder Volcanoes Stratovolcanoes 8

9. COMPOSITE VOLCANO A composite volcano is a tall, conical volcano built up by many layers of hardened lava, which solidify when they cool. The volcano grows taller each time it erupts and is covered with fresh lava.Ex-: Fuji- Japan , Vesuvius-Italy, St. Helens-USA 9

10. Dome Volcano A dome volcano is small and often forms inside the caldera of a stratovolcano. After a large eruption when large amount of magma has emptied out of the magma chamber the summit of the composite volcano collapses forming a depression.Inside the depression magma oozes out to beginforming a small lava dome. 10

11. Shield VOLCANO Shield volcanoes are large volcanoes that are built almost entirely of fluid lava flows. It has broad sloping sides and is usually surrounded by gently sloping hills in a circular or fan shaped pattern, that looks like a warriors shield. 11

12. CINDER CONE This is the simplest type of volcano. They are built from particles and blobs of congealed lava ejected from a single vent.Most cinder cones have a bowl-shaped crater at thesummit and rarely rise more than a thousand feet orso above their surroundings. 12

13. Stratovolcano Stratovolcanoes have steep sides with cones that stick out like huge bumps. They are built up when eruptions of viscous lava, tephra, and pyroclastic flows happen.It takes thousands of years for the pressure tobuild up enough in stratovolcanoes to cause aneruption. 13

14. World Most Active VolcanoesVolcano Name Location Continuous EruptionsEtna Italy 3500 yearsStromboli Italy 2000 yearsYasur Vanuatu 800 yearsAmbrym Vanuatu 1935-Tinakula Solomon Islands 1951?-Erta Ale Ethiopia 1967-Manam Papua New Guinea 1974-Langila Papua New Guinea 1960-Bagana Papua New Guinea 1972-Semeru Indonesia 1967-Merapi Indonesia 1967-Dukono Indonesia 1933-Sakura-jima Japan 1955-Suwanose-jima Japan 1949-Santa Maria Guatemala 1922-Pacaya Guatemala 1965-Arenal Costa Rica 1968-Sangay Ecuador 1934-Erebus Antarctica 1972-Piton de la Fournaise Reunion 1920-Kilauea Hawaii 1983- 14

15. EFECTS OF VOLCANOES NEGATIVE Ash fall Volcano gas Lahara Land slides 15

16. EFECTS OF VOLCANOES POSITIVE Nutrients to soil Natural beauty landscapes 16

17. The Destruction of Pompeii, 79 AD On August 24, 79 Mount Vesuvius literally blew its top, spewing tons of molten ash, pumice and sulfuric gas miles into the atmosphere. A "firestorm" of poisonous vapors engulfed the surrounding area suffocating the inhabitants of the neighboring Roman resort cities of Pompeii, Herculaneum and Stabiae. Tons of falling debris filled the streets until nothing remained to be seen of the once thriving communities. 17

18. The cities remained buried andundiscovered for almost 1700years until excavation began in1748. These excavationscontinue today and provideinsight into life during theRoman Empire. 18

19. REFERENCES National Geographic Magazine Time Magazine Wikipedia.com Blog Sites 19

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