Transcript Formation of the Earth Power Point

Formation of the Earth
In the beginning
Just a lot of Gas
• Space contained a lot
of gasses and dust
• That gas and dust
began to condense
and heat up
• Matter in the middle
heated so much the
gasses ignited
• BANG!
http://en.wikipedia.org/wiki/Galaxy
After the Bang
• After the gasses
exploded it threw
material out
• As the material
moved away from the
sun it started to cool
forming planets
http://www.psc.edu/publicinfo/news/2002/images/planets-01-full.jpeg
http://www.windows.ucar.edu/tour/link=/jupiter/atmosphere/J_evolution_4.html
Forming Earth
• Earth was formed from
the dust and gasses that
were left after the bang
• Earth started off as a
rock. It was hit by
meteors over billions of
years, which added to the
mass of the planet.
• As the planet cooled the
heavier, more dense
metals began to sink to
the inner part of the earth
http://www.ccsf.edu/Departments/History_of_Time_and_Life/content/EarthLayers.htm
Formation of the Earth
Layers of the Earth
• As the molten earth
material cooled layers
formed
–
–
–
–
Crust
Mantle
Outer core
Inner core
http://www.ccsf.edu/Departments/History_of_Time_and_Life/content/EarthLayers.htm
How do we know?
• Can’t see into the
earth
• Have only drilled
into a small part of
the earth
• Learned what we
know by studying
seismic waves and
how they travel
http://pubs.usgs.gov/gip/earthq1/corel.gif
Outer and Inner Core
The Crust
• The crust is the
outermost layer of the
earth
• It is made of two
types of crust
– Continental (35-100
km)
– Oceanic (5-10 km)
• It is not very thick
– 5-100 km thick
– We have only drilled
about 5 miles (8 km)
into the crust
• It’s a solid
• Where we live
http://www.sirinet.net/~project/MeersEarthsCrust.html
http://www.dlt.ncssm.edu/TIGER/diagrams/basics/ElementsInEarthsCrust.gif
The Mantle
• Is found under the
crust
• Is made mostly of
iron (Fe) and
magnesium (Mg)
• Where most of the
earth’s heat is
• Has convection cells
that cause the plates
to move
• Volcanoes give us a
clue to what is under
the crust
http://www.physics.sfasu.edu/astro/courses/ast105/Summary7_files/07-01.jpg
• Convection – hot rises, cold sinks
The Outer Core
• Is about 2200 km
thick
• Made mostly of iron
(Fe) and nickel (Ni)
• Is a liquid
• The outer core is
liquid, unlike the
inner core.
http://library.thinkquest.org/10136/media/layers2.jpg
The Inner Core
• Is a solid
– Due to extreme
pressure from all the
other layers of the
earth
• Is 1228 km thick
• Made of mostly iron
(Fe) with some nickel
(Ni)
http://www.llnl.gov/str/JulAug04/Fried.html
Other Names
• Crust and upper mantle – lithosphere
– Where the tectonic plates are found
• Bottom of the upper mantle – asthenosphere
– Where the convection cells are
• Lower mantle - mesosphere
http://www.visionlearning.com/library/modules/mid69/Image/VLObject-1630-030917010902.gif
Draw the layers of the Earth
• Pages 90 and 91 in “Inside the Restless
Earth”
• Include the following words; Crust, mantle,
Outer Core, Inner Core, Lithosphere,
Asthenosphere, Mesosphere.