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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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Volcano - A Volcano is an opening in the Earth’s surface through which molten material or volcanic gases are erupted.
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,
Ocean- Continental Subduction Pacific Northwest Volcanoes
Ocean- Ocean Subduction
Ocean- Ocean Subduction
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
Volcanoes are classified as either Active, Extinct or Dormant
Dormat Mt. Ranier
Magma and Erupted Materials • Parameters of volcanism: • Viscosity • Chemistry of Magma • Gases within the magma • Water content of magma
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
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.
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
Gases in Magma Water Vapor Carbon-Dioxide Carbon Monoxide Sulfur-Dioxide Hydrogen-Sulfide
Aa Lava Aa Lava