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Changing Nature of Earth Mr. Lin Image Courtesy of http://www.spacetoday.org/images/SolSys/Earth/EarthBlueMarbleWestTerra.jpg Look at the World Map. It looks like a puzzle. Can anyone tell me why? Image Courtesy of http://www.tlrp.org/international/images/world.gif Theory of Continental Drift Image Courtesy of http://www3.bc.sympatico.ca/Moon/earths.gif Image Courtesy of http://geology.com/pangeacontinental-drift.gif Theory of Continental Drift Image Courtesy of http://www.noc.soton.ac.uk/gg/classroom@sea/carlsberg/images/plate_history_lge.jpg Theory of Continental Drift • A Theory that all the continents on Earth were originally a part of one large super-continent called Pangaea. PANGAEA Image Courtesy of http://upload.wikimedia.org/wikipedia/common s/6/65/Pangaea.png • Plates on the Earth’s Crust have since moved parts of Pangaea away from each other. How Do the Continents Move? Plate Tectonics • The Earth’s surface (called the Crust) is cracked into large “plates” • These plates float on the molten rock under the crust. Image Courtesy of http://www.gsi.ie/NR/rdonlyres/A3B07F5E-D9BB4026-908D-DEB9B0217EA6/0/earth_cut.jpg Plates Image Courtesy of http://www.dkimages.com/discover/previews/1244/597340.JPG Plates Image Courtesy of http://www.windows.ucar.edu/earth/images/earth_plates_usgs_L.jpg Plate Tectonics Show Video on Plate Tectonics Plate Tectonics • When Plates are next to each other, they can move in three main ways: – Away from each other • Divergent – Into each other • Convergent – By sliding Image Courtesy of http://geothai.net/2008/images/stories/article_imag e/convergent-boundary-oceanic-continental-still.gif • Transformational Convergent Plates Convergent Plates Mountains like Mt. Everest are built by Convergent Plates Divergent Plates Transformational Mwwwaaahaha hahAHAHAH!!! So What Moves the Plates? (Let’s first investigate the layers of the EARTH) Layers of the Earth • Crust: Solid rock • Mantle: Melted rock • Outer Core: Melted metal Image Courtesy of http://www.mgm.monschau.de/seismic/image s/artikel/abb10_gross.jpg • Inner Core: Solid Metal Mantle: 1,800 miles thick. Made of magma Crust: 3-5 miles thick. Made of rocks Outer Core: 1,400 miles thick. Made of liquid nickel and iron Inner Core: 800 miles thick. Made of solid nickel and iron Layers of the Earth Image Courtesy of http://volcano.und.edu/vwdocs/vwlessons/lessons/Earths_layers/Earths_layers3.html