Earths Structure and internal energy sources

Describe the structure of the earth

Describe Oceanic crust features

1. Alternative name

2. geology

3. thickness

4. density

• known as Sima

• Primarily basalt

• 4-7 km thick

• denser than continental

Describe Continental crust features

Describe the asthenosphere

• known as Sial

• Primarily granite

• 20-70 km thick

• less dense (will not undergo subduction)

Describe the asthenosphere

Upper Mantle:

• Weaker, plastic rocks

• constantly moves due to convection currents

Describe the earths core

• Outer Core:

  • liquid

  • mainly iron

• Inner Core

  • Solid

  • iron-nickel alloy

  • temperatures up to 4,700

Describe the lower mantle

Weaker, plastic rocks

700-3,000km deep

2 sources of internal energy

Radiogenic, Primordial

Explain how primordial heat occurs

Left over from the formation of the earth. The heat lost by the Earth as it continues to cool from its original formation,

Explain radiogenic heat

produced by the radioactive decay of isotopes in the mantle and crust.

The radioactive decay of elements results in the production of daughter isotopes and release of particles and heat energy, or radiogenic heat

* Actively produced

Distribution of energy:

Internal heat is transferred from the ____ __via _________, into the mantle where it is moved on by__ ________. Afterwards, the heat escapes through__ _______ ___________ (heat carries in molten rock through the crust )

core, conduction, convection, volcanic advection