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Warm-up. What are some things that one must worry about if a volcano erupts?. Chapter 3 Section 1: Volcanoes. 9/28/2011. Learning Targets. Students will understand the characteristics of volcanoes. Students will understand the dangers of volcanoes.
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Warm-up • What are some things that one must worry about if a volcano erupts?
Chapter 3 Section 1: Volcanoes 9/28/2011
Learning Targets • Students will understand the characteristics of volcanoes. • Students will understand the dangers of volcanoes. • Students will begin to gain an understanding of the main locations of volcanoes.
Volcanoes • Volcano- a mountain built from magma (melted rock) that rises to the Earth’s surface • Volcanoes may occur on land or under the sea. • If they occur under the sea, they may eventually break the ocean surface. • One minute quick write: • What volcanoes do you know that have come from under the sea and why do you think they came from under the sea?
Local Effects of Volcanoes • A volcano erupts when the pressure on its inside becomes too great. • The land can not hold the pressure back, and BOOOOOOOOOOOOOOOOOM! Mount Saint Helens!!! • Some volcanoes have lava flowing out of them all the time, so no pressure builds up and they do not erupt. HAWAII!!! • One Minute Quick Write: • Why might some volcanoes be violent while others are not?
Local Effects of Volcanoes • PYROCLASTIC FLOWS, or clouds of hot dust, ash, and gases can flow down hills destroying and incinerating everything in its path. • Volcanic ash can mix with melted water, producing MUDSLIDES. • Ash falling to the ground can make roof buildings collapse, cause black outs, and seriously harm animals airways. (Yes, even humans.)
Global Effects of Volcanoes • Major volcanic eruptions can cause climate change for several years. • Large eruptions cause volcanic ash and sulfur gases to reach the upper atmosphere. • The sulfur and ash spreads around the globe. • They reduce the amount of sunlight reaching the Earth. • This can cause a drop in average global surface temperature. • Mount Pinatubo eruption 1991.
One minute quick-write: • After witnessing how the sulfur from volcanic eruptions can decrease Earth’s temperatures, some scientists have suggested putting a lot of sulfur in the Earth’s atmosphere to counteract Global Warming. • How do you think this is a good idea or bad idea?
YouTube Volcano Awesomeness! • http://www.youtube.com/watch?v=CgpNqrR318U&feature=relmfu • http://www.youtube.com/watch?v=vBJ9xZws7ro