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Volcanoes 101: Understanding the Power of Earth's Eruptions

Discover the fascinating world of volcanoes - from their formation and locations to the different types of magma, lava, and gases they produce. Learn about popular volcanic sites and the impact of volcanic activity on Earth's surface.

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Volcanoes 101: Understanding the Power of Earth's Eruptions

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Presentation Transcript

  1. Volcanoes!!

  2. What is a Volcano?

  3. Volcano - A Volcano is an opening in the Earth’s surface through which molten material or volcanic gases are erupted.

  4. A volcano can either be a classic volcanic cone…..

  5. Mt. St. Helens, pre-1980

  6. Mount Ranier

  7. a crack in the ground, through which lava erupts……

  8. Or a simple volcanic vent.

  9. How Magma Rises

  10. Where are volcanoes located?

  11. Major Volcanoes Around the World

  12. Volcanic Settings

  13. How and Where Volcanoes Form 1. Water in the subducted rock is released into the asthenosphere. 4. Some of the magma reaches Earth’s surface, and volcanoes form on the overriding continental plate. Oceanic lithosphere Continental lithosphere Asthenosphere 3. The magma is less dense than its surroundings, so it rises. 2. The water lowers the melting temperatures of materials in the asthenosphere, leading to magma formation. Volcanic activity takes place primarily at subduction boundaries,

  14. Ocean- Continental Subduction Pacific Northwest Volcanoes

  15. Ocean- Ocean Subduction

  16. Ocean- Ocean Subduction

  17. Diverging Boundary Volcano

  18. Hot Spot Volcano

  19. How and Where Volcanoes Form Kauai Oahu Molokai Lanai Maui Hawaii The Hawaiian Islands formed over a hot spot. Magma and volcanoes also form at hot spots. Direction of Plate Movement

  20. Major Hotspots of the World

  21. Plate Tectonics and Magma Generation

  22. Tectonic Settings and Volcanic Activity

  23. Volcanoes are classified as either Active, Extinct or Dormant

  24. Active

  25. Dormat Mt. Ranier

  26. Vesuvius

  27. Extinct

  28. Magma and Erupted Materials • Parameters of volcanism: • Viscosity • Chemistry of Magma • Gases within the magma • Water content of magma

  29. Magma and Erupted Materials Magma and Erupted Materials Viscosity: Viscosity is a measure of how thick (viscous) and sticky a liquid is. VOCABULARY viscosity lava pahoehoe aa pillow lava pyroclastic material pyroclastic flow

  30. Types of Magma

  31. Felsic Magma Characteristics: -light in color -high viscosity: means it is very thick and flows very slowly. -Associated with composite type volcanoes and continential hotspots -Found along continental-ocean subduction boundaries.

  32. Mafic Magma Characteristics: -dark in color -low viscosity: means it is thinner and flows much faster -Associated with shield volcanoes, rift zones, and oceanic hotspots -Found at divergent boundaries and oceanic hotspots

  33. Gases in Magma Water Vapor Carbon-Dioxide Carbon Monoxide Sulfur-Dioxide Hydrogen-Sulfide

  34. Types of Lava

  35. Pahoehoe Lava

  36. Aa Lava Aa Lava

  37. Pillow Lava

  38. Types of Lava Fragments

  39. Ash

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