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Volcanoes These notes go on p. 11 of your inb !!!

Volcanoes These notes go on p. 11 of your inb !!!. Volcanic Settings (Plate Boundaries). Ocean-Continent Convergence. Ocean-Ocean Convergence. CONTINENTAL divergence. Ocean Divergence. Major Volcanoes Around the World.

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Volcanoes These notes go on p. 11 of your inb !!!

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  1. VolcanoesThese notes go on p. 11 of your inb!!!

  2. Volcanic Settings (Plate Boundaries) Ocean-Continent Convergence Ocean-Ocean Convergence CONTINENTAL divergence Ocean Divergence

  3. Major Volcanoes Around the World

  4. “RING OF FIRE”:Area surrounding the pacific plate where the most volcanoes & earthquakes occur

  5. Plate Tectonics and Magma Generation

  6. Viscosity Chemistry of Magma Gases within the magma Water content of magma PARAMETERS OF VOLCANISM

  7. Active Volcanoes: recent eruptions, active magma source • Mt. Etna, Italy • Dormant Volcanoes: no recent eruptions, but still has an active source of magma • Mt. St. Helens, USA • Extinct Volcanoes: no recent eruptions, no source of magma • Northwestern Hawaiian Islands Volcanic activity

  8. Viscosity- the resistance of lava to flow • Ex: The more viscous the lava, the thicker and stickier the material & the harder it is to flow (honey vs. water) TERMS TO KNOW: • depends on the amount of silica • the type of crust being melted determines the amount of silica!

  9. Caldera: large crater shaped basin that forms when the top of a volcano collapses Terms to know:

  10. Formation of Crater Lake

  11. Kaui Oahu Molokai Lanai Maui Hawaii Terms to know: • Hot Spot- random upwelling of magma NOT associated with convection in the mantle • create a special type of volcanism not associated with plate boundaries • Ex: Hawaii, Yellowstone & Iceland

  12. Tectonic Settings and Volcanic Activity

  13. Cinder Cone 1. Cinder Cones: explosive eruptions, small but steep slopes, pyroclastics 3 types of volcanic cones:

  14. Volcano Types

  15. 2. Shield: non-explosive eruptions, fluid basaltic lava, gentle broad slopes 3 types of volcanic cones:

  16. Volcano Types

  17. 3. Composite Cones/Stratovolcanoes: alternating between lava and pyroclastics, explosive and non-explosive eruptions, very steep/tall 3 types of volcanic cones:

  18. Volcano Types

  19. Volcanism at different plate boundaries

  20. Effusive Eruption (non-violent): low viscosity, flows easily, gases escape easily • Magma Type: mafic (dark, dense seafloor) • Volcano Type: Shield Volcanoes • Lava Type: Pillow http://www.youtube.com/watch?v=DdIUuUY0L9c C Mid-ocean ridges & oceanic hot spots

  21. Pillow Basalts (underwater) http://www.youtube.com/watch?v=DdIUuUY0L9c • AA lava- jagged lava • Pahoehoe- ropey, smooth lava C Basaltic Lava Types

  22. Mostly Explosive Eruption (violent):high viscosity, does not flow easily, gases trapped, hard to predict explosions Magma Type: felsic & mafic Volcano Type: Composite Cone (Stratovolcanoes) & cinder cones Other Features: gas flows, calderas, aerial bombs C Subduction boundaries

  23. searing superheated gas and volcanic ash & dust; very fast Also called “NueeArdente” C PYROCLASTIC FLOWS http://www.youtube.com/watch?v=-H_HZVY1tT4 Mt. St. Helens Eruption http://www.youtube.com/watch?v=WxlRpuTed6g Pyroclastic Flow

  24. Debris Avalanche and Eruption of Mount St. Helens, Washington

  25. C Continental divergent boundary & Continental hot spots • Explosive Eruption (violent):high viscosity, does not flow easily, gases trapped, hard to predict explosions (always explosive!) • Magma Type: felsic or rhyolitic • Volcano Type: Composite Cone (Stratovolcanoes),cinder cones, dome complexes • Other Features: gas flows, calderas, aerial bombs, pyroclastic flows

  26. Basaltic Magma Rhyolitic Magma Andesitic Magma Silica Content Least (~50%) Intermediate (~60%) Most (~70%) Gas Content Least Intermediate Most Viscosity Least viscous Intermediate Most viscous Type of Eruption Rarely explosive Usually explosive Sometimes explosive Melting Temp. Highest Intermediate Lowest Location Subduction boundaries Rifts, oceanic hot spots Continental hot spots Magma and Erupted Materials

  27. Draw an exaggerated, cartoon form of a type of volcano • Cinder • Shield (Dome) • Composite • Write a 5-6 sentence summary about it’s “personality.” Must include type of eruption, type of lava, size/shape, and location. Volcano CarIcAtures

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