Transcript Theory of Plate Tectonics

Earth’s Composition
Lesson 1: Layers of the Earth
SC.7.E.6.1
• Student will be able to describe the
different layers of the earth.
Earth is like a peach!!
• Skin of the peach is
the crust
• Meat of the peach
is the mantle
• Pit of the peach is
the core
Layers of the EARTH
CRUST
State of Matter: Solid
Composition: Silicon & Oxygen
Density: Less than all 3.9g/cm3
Distance below surface: Outer
surface
Thickness: Thinnest layer
MANTLE
State of Matter: Solid
Composition: Magnesium &
iron silicates
Density: 3.9g/cm3
Distance below surface:
670-2900km
Thickness: Thick
INNER CORE
State of Matter: Solid
Composition: Iron
Density: 13.0g/cm3
Distance below surface:
6,370km
Thickness: Thickest layer
Because of it’s density
OUTER CORE
State of Matter: Liquid
Composition: Iron
Density: 11.1g/cm3
Distance below surface:
5,150km
Thickness: Thick fluid like
Material.
Crust
• Brittle rocky outer layer of
the Earth.
• Thinnest of the layers
• The least dense
• Made of: Silicon & Iron
• Layer where we live!!!!
2 Parts
• Continental Crust
• Oceanic Crust
Mantle
• Thick middle layer in the
solid part of the Earth
• Immediately below the crust
• Convection currents in the
mantle cause the plates
above to move
• Made of magnesium
2 Parts
• Upper Mantle
• Lower Mantle
BONUS FACTS: 2900 km below
earth’s surface (7,250 laps
around 400 meter track)
Inside the Mantle
Lithosphere
• The crust and part of
the upper mantle =
lithosphere
• Less dense than the
material below it so it
“floats”
Asthenosphere
• The plastic layer (easily
flowing) inside the
mantle
• The lithosphere float on
top of the asthenosphere
=PLATE TECTONICS
Outer Core
• Made of a thick
fluid like
LIQUID iron
• Directly below
the mantle
BONUS FACTS
5,150 km below
earth’s surface
(12,875 laps around
a 400 meter track)
Inner Core
Liquid Iron
Solid
IRON
Liquid Iron
• Spinning SOLID
ball made of iron
and nickel
• Layer with the
most density
BONUS FACTS 6,370
km below earth’s
surface (15,925 laps
around a 400 meter
track)