Download Structure of the Earth

Structure of the Earth
What are the layers of the Earth

Crust
Thin layer of rock
 Surrounds Earth like a shell surrounds an egg
 Two types of crust
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
Continental crust
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Makes up the continents and some major islands
Oceanic crust

Makes up the ocean floor
Between 6-70 km thick (about 3.7 – 43.5
miles)
 Furthest we have ever been in 12.3 Km (7.6
miles) – This is 0.2% of the way there

Two Kinds of Crust

Continental Crust
Thicker of the two
 Less Dense
 Composed mostly of Granite
 Avg. of 20 – 40 Km thick (12 – 24.9 Miles)


Oceanic Crust
Thinner of the two
 More Dense
 Composed mostly of Basalt
 Avg. of 6 – 11 Km thick (3.7 – 6.8 Miles)

Mantle
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
Thickest Layer of Earth
Made mostly of Hot Molten Rock
Very, Very top is cool ridged rock
About 2900 Km (1802 miles)
870 – 4400 C (1598 – 7952 F)
Outer Core

Layer of liquid metal
 Iron



& Nickel
2300 Km (1429 Miles)
4400 – 6100 C (7952 – 11,012 F)
There is more pressure than the mantle
but less pressure than the inner core
Inner Core

Solid ball of metal
 Iron
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

& Nickel
2400 Km in diameter (1491 Miles)
7000 – 8000 C (12,632 – 14,432 F)
Extreme pressure keeps it solid
Densest layer of the Earth
Lithosphere


Made up of the crust and very top rigid
part of the mantle
This is what the tectonic plates are
made of
 Most
plates have both continental and
oceanic crust


On continents it is believed to be an
average of 150 Km (93 miles)
In ocean it is believe 50-100 Km (31 –
62 miles)
Asthenosphere

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
The hot soft layer of molten rock in the
middle mantle on which the lithosphere
rests
Flows slowly like hot tar
Estimated to be 85- several hundred
Km thick (50 – several hundred miles)