Chapter 8.15-18 by Ayanna Desai https://padlet.com/ayanna_desai/lztpiofeh295 Made with a dash of wit en-us 2018-04-12 14:37:02 UTC 2018-04-12 16:17:10 UTC hello@padlet.com 8.15 Summary ayanna_desai https://padlet.com/ayanna_desai/lztpiofeh295/wish/251177250 Volcanoes are located along convergent and divergent plate boundaries. They can be found in the middle of plates at hotspots. Magma can be created when temperature rises, pressure lowers, or water is added. Volcanoes may be active, dormant, or extinct. This depends on whether there is the possibility of magma in their magma chambers.

]]> 2018-04-12 14:41:19 UTC https://padlet.com/ayanna_desai/lztpiofeh295/wish/251177250 8.16 Summary ayanna_desai https://padlet.com/ayanna_desai/lztpiofeh295/wish/251177398 Subduction at convergent plate boundaries leads to melting and volcanoes. Convergent plate boundaries line the Pacific Ocean basin so that volcanic arcs line the region. Melting at divergent plate boundaries is due to release of pressure.  At mid-ocean ridges seafloor is pulled apart and new seafloor is created. Rifting in a continent can create a
new ocean eventually.

]]> 2018-04-12 14:41:35 UTC https://padlet.com/ayanna_desai/lztpiofeh295/wish/251177398 8.17 Summary ayanna_desai https://padlet.com/ayanna_desai/lztpiofeh295/wish/251177495  Volcanoes grow above hotspots. A hotspot is a zone of melting above a mantle plume. Hotspot volcanoes are better able to penetrate oceanic crust than continental crust. We see many more hotspot volcanoes in the oceans. Shield volcanoes commonly form above hot spots in the oceans.

]]> 2018-04-12 14:41:42 UTC https://padlet.com/ayanna_desai/lztpiofeh295/wish/251177495 8.18 Summary ayanna_desai https://padlet.com/ayanna_desai/lztpiofeh295/wish/251177646 Magmas differ in composition, which affects viscosity. Magma composition has a large effect on how a volcano erupts. Felsic lavas are more viscous and erupt explosively or do not erupt. Mafic lavas are less viscous and erupt Effusively. Different lava types create different rock types, such as pahoehoe and a’a. Lavas that cool underwater become
pillow lavas.

]]> 2018-04-12 14:41:57 UTC https://padlet.com/ayanna_desai/lztpiofeh295/wish/251177646 VOCAB: ayanna_desai https://padlet.com/ayanna_desai/lztpiofeh295/wish/251231174 active volcano: Volcano that is currently erupting or is just about to erupt. Currently erupting or showing signs of erupting soon
dormant volcano: Volcano that is not currently erupting but has erupted in the recent past. No current activity, but has erupted recently.
extinct volcano: Volcano that has not erupted in recorded history and is unlikely to erupt again. No activity for some time; will probably not erupt again.
continental rifting: A divergent plate boundary within a continent causes the continent to thin and break apart.
fissure: Crack in the ground that may be the site of a volcanic eruption.
hotspot: Fixed region of hot material that creates magma and generates volcanoes.
mantle plume: Zone of hot material that rises toward the surface from deeper in the mantle and can generate hotspots.
magma chamber: Region below a volcano where magma and gases collect.
viscosity: Thickness of a liquid; its resistance to flow.



]]> 2018-04-12 16:11:38 UTC https://padlet.com/ayanna_desai/lztpiofeh295/wish/251231174 ayanna_desai https://padlet.com/ayanna_desai/lztpiofeh295/wish/251232043 2018-04-12 16:13:19 UTC https://padlet.com/ayanna_desai/lztpiofeh295/wish/251232043 ayanna_desai https://padlet.com/ayanna_desai/lztpiofeh295/wish/251232206 2018-04-12 16:13:37 UTC https://padlet.com/ayanna_desai/lztpiofeh295/wish/251232206 ayanna_desai https://padlet.com/ayanna_desai/lztpiofeh295/wish/251232580 2018-04-12 16:14:20 UTC https://padlet.com/ayanna_desai/lztpiofeh295/wish/251232580 ayanna_desai https://padlet.com/ayanna_desai/lztpiofeh295/wish/251233086 2018-04-12 16:15:21 UTC https://padlet.com/ayanna_desai/lztpiofeh295/wish/251233086 Interesting facts ayanna_desai https://padlet.com/ayanna_desai/lztpiofeh295/wish/251233367 -A volcano is a mountain that opens downward to a pool of molten rock below the surface of the earth. When pressure builds up, eruptions occur.
-In an eruption, gases and rock shoot up through the opening and spill over or fill the air with lava fragments. Eruptions can cause lava flows, hot ash flows, mudslides, avalanches, falling ash and floods.

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