Download Changing Nature of Earth

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
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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
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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