Transcript Volcanoes
Volcanoes What is a volcano? • An opening in the Earth that erupts gases, ash, and lava. http://www.youtube.com/watch?v=xExdEXOaA9A Mountains form when layers of lava, ash, and other materials build up around these openings. How are volcanoes formed? Convergent volcanoes • At convergent boundaries, one plate subducts (sinks) under the other, the plate melts and magma is forced to the surface. • These volcanoes have the most violent eruptions • http://www.classzone.com/books/earth_science/terc/content/visualizations/es0902/es0902page01.cfm?chapter_no=visualization Divergent volcanoes • At divergent boundaries, plates move apart and magma rises to the surface. • Also known as seafloor spreading. • These eruptions are not as violent • http://www.classzone.com/books/earth_science/terc/content/visualizations/es0903/es0903page01.cfm?chapter_no=visualization http://www.youtube. com/watch?v=y3YN pzZWbmU Lava in the water Hot Spot Hot Spots • Form in the middle of plates. • As the plate moves, new volcanoes are created. http://www.youtube.com/watch?v= AhSaE0omw9o 2 1 1 2 3 • When the plate moves, the older volcanoes lose their magma source and are now dormant (inactive) •http://www.classzone.com/books/earth _science/terc/content/visualizations/es0 904/es0904page01.cfm?chapter_no=vi sualization Iceland • Divergent Geothermal Activity on Iceland Surtsey Natural geothermal pools Geysers and mud pots Hawaii • Hot Spot http://www.youtube.com/watch?v=bYv6V 5EJAKc Hot Spot Locations http://mms.nps.gov/yell/ofvec/exhibits/eruption/volcanoes/hotspot3.htm Soufriere Hills in Montserrat • Convergent If the Pacific Plate stops moving, what will happed to the Big Island of Hawaii? X It will just keep getting bigger! What destruction can volcanoes cause? Block roadways Collapse buildings www.maps.google.com Lahars • Mudslides created by volcanic eruption • Heat from volcano melts glaciers on mountain • Will usually take out everything in its path Can cause lung disease in animals and humans Ring of Fire -a chain of convergent volcanoes found circling the Pacific Ocean http://www.classzone.com/books/earth_science /terc/content/investigations/es0810/es0810page 01.cfm?chapter_no=investigation How fast do plates move computer investigation http://www.youtube.com/watch?v=bgRnVhbfIKQ&feature=related Mount st helens Volcano Review Where do we find most volcanoes? • Near plate boundaries What are the three types of volcanoes? • Convergent, divergent, and hot spot What and where is the Ring of Fire • A chain of volcanoes circling the Pacific Ocean