1. Volcano WebQuest Follow-Up

2. A volcano is: An opening in the earth’s crust that allows magma, pyroclasts, and gases to escape

3. Volcano Features: Dome: build up of lava and debris surrounding a vent to form a volcano Vent: the opening in the earth that volcanic materials get erupted from

4. Things that can come out of a volcano: Lava: molten rock, ability to flow depends on Silica and moisture content (called magma when found inside the earth), made up of crystals volcanic glass, and bubbles Ash: rock, mineral, volcanic glass (all pieces ejected are around the size of a pinhead) Tephra: fragments exploded from a volcano (bomb, block, lapilli, ash, cinder)

5. Lahar: fast moving mix of rock pieces and water, like a fast moving river of muddy rock Gas: CO 2, H 2 O vapor, SO 2 Pyroclastic Flow: avalanche of hot volcanic materials, travel very quickly

7. People tend to live near volcanoes because: They have very fertile soils Contain valuable mineral deposits Are very scenic Tourism

8. Bad things volcanoes can do to the environment: Destroy the land Kill plants, animals, and people Put deadly gases into the air (short term) Provide about 3% of yearly CO 2 output

9. Viscosity is: The ability of a material to resist flow.

10. How does viscosity effect an eruption? The more viscous the lava, the more explosive the eruption. More viscous materials flow very slowly so they ‘jam up’ the volcano vent until there’s too much pressure and they explode.

11. Stratovolcano Lava viscosity=High Gases: high which leads to explosive eruptions Size: medium Eruption Style: alternates eruptions of lava flows and pyroclastic flows/explosions Found: subduction zones Examples: Mt Fuji, Mt St Helens, Krakatoa

13. Cinder Cone Lava viscosity=Highest Gases: high, gas charged lava carries lava up in lava fountains Size: smaller with narrow piles of pyroclastic particles Eruption Style: explodes vertically with small cinders forming and falling straight back down Found: typically found on sides of other volcanoes Examples: Paricutin, Wizard Island

15. Shield Volcano Lava viscosity=Low Gases: low Size: largest, big base with gently sloping sides Eruption Style: fluid flow from all directions around vent Found: Hotspots Examples: Hawaii, Galapagos, Iceland

17. Hotspots are: Areas of volcanism not at plate boundaries. Magma finds a weak spot in the earth’s crust and forces it’s way up to the surface. Ex: Hawaii, Yellowstone

18. How was Hawaii formed? The Pacific Plate is moving Northwest over the stationary hotspot that supplies magma to the Hawaiian volcanoes. As a result, an island chain formed with the oldest volcano being the furthest NW and the youngest (and still active one) being the furthest south.