Download Layers of Earth Comparisons

Comparing
the
Layers of Earth
S6E5.a.
Earth’s layers are compared by:
• Temperature
• Density
– (the thickness or depth of the layer)
• Composition
– What each layer is made of or how it is
described
Which is the outermost layer?
THE CRUST
Temperature:
Temp of the air outside to
1600 °F
Density: 5km – 70km
thick
The Crust: What’s it made of?
• 2 types of crust:
– Oceanic – mostly basalt rocks
The thinnest crust
– Continental – mostly granite rocks
The thicker crust
What do you find on Earth’s crust?
•
•
•
•
Rocks
Mountains
Soil
Water
• What else???
Where the Crust ends and the
Mantle begins is an area called
the MOHO Discontinuity.
1909: Andrija Mohorovicic
discovers the moho
discontinuity, which is the
boundary between Earth’s
crust and mantle.
Next is the Mantle…
• Mantle Temperature range:
From 1600 °F to 6700 °F
• Density of the WHOLE Mantle = 2867
km!
–Let’s break it apart!
The Mantle
• Made of 3 distinct
areas:
–Lithosphere
–Asthenosphere
–Lower Mantle
Mantle’s Lithosphere
• Density =
approx 100 km
• Composition:
–Rigid layer
–Rocky like Crust
–“Lithos” means “Stone”
• Unique? Made up by part of the Crust!
Mantle’s Asthenosphere
• Density = 300 km
• Composition:
– Plastic-like
– Solid, but softer
– “Asthenes” means “weak”
– Unique? Makes the plates move! Because it’s
slowly flowing.
Lower Mantle
• Density = 2467 km
• Composition:
– Solid
Unique? Semi-rigid
 Gutenberg
Discontinuity
Where the Mantle ends and
the Outer Core begins is an
area called the GUTENBERG
DISCONTINUITY
Outer Core
• Temperature = 6700 °F to 7800 °F
• Density = 2266 km
• Composition:
– Liquid, Molten Metal
(Fe & Ni)
What makes the Outer Core
unique?
• Creates Earth’s
magnetic field
• High temps from the
formation of the
planet keep the Iron
(Fe) & Nickel (Ni)
liquid
Inner Core
• Temperature = 7800 °F to
13000 °F
HOTTEST LAYER!!!
• Density = 1216 km
• Composition:
– Dense, solid metal ball of Fe & Ni!
What’s unique about the Inner
Core?
• Extreme pressure squeezes the
atoms of the Fe & Ni so much,
they cannot spread out!
• Stays solid!