1. VOLCANOES ERUPTING MOUNTAINS

2. VOLCANOES What is a volcano? What is a volcano? A volcano is a mountain caused by erupting lava from the mantle. A volcano is a mountain caused by erupting lava from the mantle.

3. VOLCANO FEATURES What are the features of a volcano? What are the features of a volcano? Vent: pathway the magma takes from the chamber to the crater Magma chamber: the storage of magma Magma chamber: the storage of magma Crater: the bowl shape at the top of a volcano. Crater: the bowl shape at the top of a volcano.

4. VOLCANO FEATURES What are the features of a volcano? What are the features of a volcano? Bomb: football shaped blob that cools in the air Bomb: football shaped blob that cools in the air Pyroclastic flow: Hot ash and gases that flow down the mountain at great speeds. Pyroclastic flow: Hot ash and gases that flow down the mountain at great speeds. Cinder: a lava rock Cinder: a lava rock

10. VOLCANO FEATURES What are the features of a volcano? What are the features of a volcano? Lahar: a mudflow caused by the eruption of a volcano Lahar: a mudflow caused by the eruption of a volcano Lava flow: Lava flowing from a fissure in the crust.

11. What is viscosity What is viscosity What is viscosity Viscosity is the ability of lava to resist flow Viscosity is the ability of lava to resist flow High viscosity=slow flow. Lava has lots of silica or lower temp. High viscosity=slow flow. Lava has lots of silica or lower temp. Low viscosity=fast flow. Lava has high temp or low silica Low viscosity=fast flow. Lava has high temp or low silica

12. High Viscosity Fluid

15. Volcano location Where are most volcanoes found? Where are most volcanoes found? What are hot spots? What are hot spots? They are found on plate boundaries. They are found on plate boundaries. Hot spots are places where magma is close to the crust causing a volcano, but not on a plate boundary. Hot spots are places where magma is close to the crust causing a volcano, but not on a plate boundary. Exp: Hawaii, Yellowstone, Iceland Exp: Hawaii, Yellowstone, Iceland

18. Stop and Think! Stop and Think! Would a volcanic eruption be likely to occur on the east coast of the United States? Would a volcanic eruption be likely to occur on the east coast of the United States? Explain. Explain.

19. Different Types Of Volcanoes What are the different types of volcanoes? What are the different types of volcanoes? Cinder Cone Cinder Cone Composite cone/ Strato volcano Composite cone/ Strato volcano Shield cone Shield cone Caldera Caldera

20. Cinder cones What are cinder cones? What are cinder cones? Explosive volcanoes with very viscous lava. Explosive volcanoes with very viscous lava. Made out of cinder rocks and very steep Made out of cinder rocks and very steep Exp: Sunset crater in Az. Exp: Sunset crater in Az.

21. Cinder Cone Volcanoes

22. Shield cones What is a shield cone? What is a shield cone? A broad and flat volcano in the shape of a shield. A broad and flat volcano in the shape of a shield. Made out of lava flows-lava is not viscous Made out of lava flows-lava is not viscous Example: Hawaiian Islands Example: Hawaiian Islands

23. Shield Volcanoes

24. Composite Cones/Strato Volcano What is a composite cone? What is a composite cone? A composite cone is a volcano made of everything. A composite cone is a volcano made of everything. Lava flows, lahars, cinders, pyroclastic flows etc. Lava flows, lahars, cinders, pyroclastic flows etc. Most common type Most common type Exp. Mt. St. Helens, Vesuvius, Krakatoa Exp. Mt. St. Helens, Vesuvius, Krakatoa

25. Composite Volcano

28. What is a caldera? What is a caldera? What is a caldera? A huge crater left in the ground after a volcano has erupted. A huge crater left in the ground after a volcano has erupted. Calderas blow all the material out and then collapse Calderas blow all the material out and then collapse Exp: Yellowstone National Park Exp: Yellowstone National Park

29. Stop and Think! Stop and Think!

30. In 1883, the island of Krakatoa was destroyed by a tremendous volcanic eruption. Huge amounts of volcanic dust were hurled into the air. This dust remained in the air for several years before settling. These years were referred to as the “years without summers.” Explain why this was so. In 1883, the island of Krakatoa was destroyed by a tremendous volcanic eruption. Huge amounts of volcanic dust were hurled into the air. This dust remained in the air for several years before settling. These years were referred to as the “years without summers.” Explain why this was so.

31. Caldera