chapter 5: volcanoes es 5.2 volcanic eruptions
TRANSCRIPT
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Chapter 5: Volcanoes
ES 5.2 Volcanic Eruptions
Inside a Volcano
Magma Chamber: Collection of magma under volcano
Pipe: Long tube connecting chamber to surface
Vent: Opening at top (or sides) where magma leaves volcano
Lava Flow: The spread of lava on the surface
Crater: Bowl shaped feature at the top of volcano that surrounds the vent
Volcanic Eruptions
When a volcano erupts, the force of the expanding gases pushes magma from the magma chamber to the pipe until it flows or explodes out of the vent.
Mt. St. Helen’s Volcanic Eruption http://youtu.be/xP2dreOI8gI
Types of Eruptions
Explosive Eruption:
High Silica Content
Thick and Sticky This magma
builds up in the pipe
This build up traps gases
Then BOOM!!! This eruption
spreads ash, cinders, and bombs!
Types of Eruptions
Quiet Eruption:
Hot and/or Low Silica Magma
Thin and Runny/Flows Easily
Produce different types of Lava; creating different type of igneous rock
Hawaii was formed by Quiet Eruptions
Hazards of Quiet Eruptions
Quick moving lava ran burn and bury everything in its path
Video of slow moving Lava destroying Hawaii http://youtu.be/HpNWL
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Hazards of Explosive Eruptions
Pyroclastic Flows: A hot, quick moving cloud of ash, cinder, and bombs that moves down the side of a volcano
Video of Pyroclastic Flows: http://youtu.be/WxlRpuTed6g
Stages of Volcanoes
Active: A volcano that is erupting or showing signs of eruption in the near future
Dormant: aka Sleeping… Expected to be active in the near future
Extinct: aka Dead… Unlikely to ever erupt again. (Ex: hot spot volcanoes)