1. Volcanoes

2. Definitions: Volcano – Hot Spot – A mountain that forms when lava, ash, rocks, and melted rock material piles up and hardens. Eruptions may be violent or “peaceful”. A location of abnormal amounts of heat in the mantle. The heat/pressure forces magma up through the crust. As a plate moves over top, a row of volcanoes are formed. – E.g. - Hawaii

7. Facts:  Volcanoes can be found on land or on the ocean floor.  They are common along plate boundaries.  Volcanoes erupt differently mainly due to the viscosity of the magma. The more viscous the magma, the more violent the eruption.  E.g. – Molasses is more viscous than water.

8. Drawings: (2 ways volcanoes are made) Hot SpotSubduction Zone

9. 3 ways to classify: Active – Dormant – Extinct – are erupting or have recently erupted have not erupted for a long time but show signs of underground activity have not erupted for a long time and show no signs of underground activity

10. 3 types of volcanoes: Shield  Gently sloped sides, lava hardens to form wide base  Erupts with little force  Made mostly of basalt Interesting Fact: The 2 types of lava are Aa and Pahoehoe

11. Aa

14. Pahoehoe

17. 3 types of volcanoes (cont.): Cinder Cone  Steep sides  Erupts with tremendous force E.g. – Krakatau  Indonesia - 1883  could be felt in London and Australia

18. 3 types of volcanoes (cont.): Composite Cone  Alternating layers of rock, lava, and ash  Erupts with either tremendous force or little force E.g. – Mt. Saint Helens  Washington - May 18, 1980  60 people were killed

19. VEIDescriptionPlume HeightVolumeClassificationHow oftenExample 0non-explosive< 100 m1000s m3HawaiiandailyKilauea 1gentle100-1000 m10,000s m3Haw/StromboliandailyStromboli 2explosive1-5 km1,000,000s m3Strom/VulcanianweeklyGaleras, 1992 3severe3-15 km10,000,000s m3VulcanianyearlyRuiz, 1985 4cataclysmic10-25 km100,000,000s m3Vulc/Plinian10's of yearsGalunggung, 1982 5paroxysmal>25 km1 km3Plinian100's of yearsSt. Helens, 1980 6colossal>25 km10s km3Plin/Ultra-Plinian100's of yearsKrakatau, 1883 7super-colossal>25 km100s km3Ultra-Plinian1000's of yearsTambora, 1815 8mega-colossal>25 km1,000s km3Ultra-Plinian10,000's of yearsYellowstone, 2 Ma