Download File - Earth Science With Mrs. Locke

We know what’s there b/c
Study the crust directly
 To learn about other layers:

 Earthquakes
 Volcanoes
 Rocks pushed to the surface
Two ways to divide the Earth
Compositional
Layers
 What
each
layer is
made of
 There are 3
 CRUST
 MANTLE
 CORE
Physical Layers
Based on how solid the
layer is
 There are 5

 LITHOSPHERE
 ASTHENOSPHERE
 LOWER MANTLE
(MESOSPHERE)
 OUTER CORE
 INNER CORE
Two ways to divide the Earth
Compositional
Layers
Physical Layers
http://pubs.usgs.gov/gip/dynamic/graphics/FigS1-1.gif
The Crust:





Outer most
Thinnest
2 types
(continental and
oceanic)
Well studied
Made of mostly
oxygen and silicon
minerals, the light
elements
http://www.bbc.co.uk/schools/gcsebitesize/geography/images/tec_001.gif
The Lithosphere

Made of the crust and small upper part
of mantle

They are glued together like a piece of a puzzle
Broken into plates
 About 150 km thick

http://images.yourdictionary.com/lithosphere
The Asthenosphere
Middle part of mantle
 Rock is solid but fluid
 Moves due to
convection causing
plates to drift
 250 km thick

http://www.windows2universe.org/earth/images/convection.gif
NOTE: this picture shows the convection of the asthenosphere but is way off in scale and missing the lower
mantle
Lower mantle
Thickest layer
(3000 km thick)
 Strong
 Solid
 Hotter than crust

http://seismo.berkeley.edu/faq/iup/earth.gif
The Mantle
largest layer
 Divided into three sections

 Solid bottom of lithosphere
 Semi-rigid asthenosphere
 Solid lower mantle

Made of magnesium, silicon, oxygen,
and iron- slightly denser elements
Outer Core
Extremely hot
 Under enormous pressure
 Very dense
 Mostly iron and nickel
 Molten
 2200 km thick

http://www.mnh.si.edu/earth/text/images/4_0_0_0/4_1_5_0_magnetic_01.jpg
Inner Core





Even hotter, under more pressure, and
denser.
Mostly iron and nickel
Solid (under such pressure that the atoms
cannot spread out enough to be liquid)
1200 km thick
It spins
* So much pressure you’d be squeezed smaller than a marble.