chapter 7: lesson 3
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Chapter 7: Lesson 3. VOLCANOES. Pages D30 and D31. How do Volcanoes Form?. What is a Volcano?. A place where molten rock, hot gases, and solid rock erupt It is an opening in the crust. - PowerPoint PPT PresentationTRANSCRIPT
Chapter 7: Lesson 3
VOLCANOES
HOW DO VOLCANOES FORM?Pages D30 and D31
What is a Volcano?
• A place where molten rock, hot gases, and solid rock erupt
• It is an opening in the crust
• Vent: central opening in a volcanic area through which magma may escape
• Lava: magma that comes out of the vent–Erupted material cools and hardens
around the vent. This is a volcano!
• Crater: a cup-like hollow that forms at the top of a volcano and around the vent.
Volcano collapses and causes a larger crater
CALDERA
Volcanoes occur in belts, or long lines...
• Pacific Ring of Fire–Circles the Pacific Ocean
• Another is located around the Mediterranean Sea through Iran and continues through Indonesia to the Pacific
• 80% of land volcanoes are found on these two belts
• On the ocean floor, volcanoes line the mid-ocean ridges.
• Volcanoes form around boundaries
• Rift volcanoes: Form at divergent boundaries
• Hot Spot: a hot part of the mantle. Magma melts up through the crust. Middle of the plate is moving over a hot spots
Hawaiian Islands