Volcanoes

1. Volcanoes By: Bridger Skillicorn 3/11/10

2. Shield volcano Shield volcanoes are formed when a weak spot in the earths surface oozes lava gradually building up a sloping hill. Shield volcanoes formed the Hawaiian islands. Crater Main vent Side vent Magma chamber Magma

3. Composite volcano Lava flows alternate with explosive eruptions with ash cinders and bombs. Composite volcanoes are tall cone shaped mountains witch are made up of layers of ash alternating with layers of lava. Examples are Mt. St. Helens. Ash bombs cinders Crater Layers of ash alternate with layers of lava Central vent

4. Cinder Cone Volcano A cinder cone is a tall steep hill or mountain the lava is thick and sticky and may produce ash ciders and bombs. All the material from the eruption piles up around the vent and creates a cinder cone. Ashcindersand bombs Layers of cinders vent

5. Caldera huge eruptions Empty the main vent of a volcano and the magma chamber. The mountain becomes totally empty making the volcano extinct . The top of the mountain collapses sometimes forming a lake at the top. Lake that has formed at the top Layersof ash alternate with layers of lava Lava tube

6. Hot Springs and Geysers Under ground water that is located at a thin part of the crust where lava rises starts to get hot. It creates steam The water and steam gets trapped in a narrow crack It builds up pressure. After the pressure builds up so high it bursts out of the crack creating a geyser. And body of water that get heated by near lava is a hot spring. Steam and water Hot spring magma Pool of water below geyser

7. Quiet Eruptions Explosive eruptions A volcano that erupts quietly the lava just flows Making the volcano bigger a volcano that erupts quietly is a shield volcano. An explosive eruption Creates usually ash cinders and bombs .Examples of explosive volcanoes are cinder cone volcanoes , and composite volcanoes.