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MEXICO. Introduction to Volcanoes!. ECUADOR. 8SCIENCE. PASTO. INDONESIA. COSTA RICA. What is a volcano?. A volcano is an opening in the Earth’s surface Most volcanoes are dormant Not currently active Active volcanoes Hawaii: Kilauea volcano Iceland: “the land of fire and ice”.
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MEXICO Introduction to Volcanoes! ECUADOR 8SCIENCE PASTO INDONESIA COSTA RICA
What is a volcano? • A volcano is an opening in the Earth’s surface • Most volcanoes are dormant • Not currently active • Active volcanoes • Hawaii: Kilauea volcano • Iceland: “the land of fire and ice”
How is a volcano formed? • Inside the earth heat and pressure causes rock to melt and turn to magma • Magma is forced up to the surface of the Earth because it is less dense • flows out through an opening called a vent • The lava cools quickly to form layers
Where do volcanoes occur? • Directly related to the movement of the Earth’s plates along plate boundaries • Occur where tectonic plates are moving together or apart • Or may be formed by a hot spot • Plates moving apart: Mid-Atlantic ridge separates and forms long cracks • Plates moving together: Nazca and South American plates are being forced under the Caribbean plates
Hot Spots • Hot spots: Ex. Hawaiian islands are volcanic islands but are not found on the edge of the plates • Some areas in the mantle are hotter than others • These hot spots melt rock and it is forced upwards towards the crust • Volcanoes are formed in a line because the Pacific plate is moving over the hot spot