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/pangea-continental-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.
• Plates on the Earth’s Crust have since moved parts of Pangaea away from each other.
Image Courtesy of http://upload.wikimedia.org/wikipedia/commons/6/65/Pangaea.png
PANGAEA
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-D9BB-4026-908D-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• Transformational
Image Courtesy of http://geothai.net/2008/images/stories/article_image/convergent-boundary-oceanic-continental-still.gif
Convergent Plates
Convergent PlatesMountains like Mt. Everest are built by Convergent Plates
Divergent Plates
Transformational
MwwwaaahahahahAHAHA
H!!!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
• Inner Core: Solid Metal
Image Courtesy of http://www.mgm.monschau.de/seismic/images/artikel/abb10_gross.jpg
Inner Core: 800 miles thick. Made of solid nickel and iron
Outer Core: 1,400 miles thick. Made of liquid nickel and iron
Mantle: 1,800 miles thick. Made of magma
Crust: 3-5 miles thick. Made of rocks
Layers of the Earth
Image Courtesy of http://volcano.und.edu/vwdocs/vwlessons/lessons/Earths_layers/Earths_layers3.html