Formation of the EarthFormation of the EarthIn the beginning

Just a lot of GasJust 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 BangAfter 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 EarthForming 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 EarthFormation of the Earth

Layers of the EarthLayers 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?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 CoreOuter and Inner Core

The CrustThe 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.htmlhttp://www.dlt.ncssm.edu/TIGER/diagrams/basics/ElementsInEarthsCrust.gif

The MantleThe 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 CoreThe 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 CoreThe 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 NamesOther 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 EarthDraw 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.