1.4 Earths Conveyor Belt

Question 1

Lithosphere (crust)

Answer 1

Split into tectonic plates
Brittle
Coolest part - air temp about 900 degrees
Density ranges from 2.7 to 3.3 grams per cm3
Least dense part on the planet

Question 2

Asthenosphere (mantle)

Answer 2

Partially molten
Mainly composed of peridotite
Temp range from 1000-4000
Density range from 3.4 to 5.6 grams per cm3
Convention currents generated

Question 3

Core

Answer 3

Approx half the diameter of the earth
Mostly made out of iron and nickel
Hottest part of the planet
4000-5000
Densest part of the planet 9-13 grams per cm3. Makes up 1/3 of the earths mass
Divided into a solid inner and liquid outer core

Question 4

Earths internal structure

Answer 4

• Most heat is generated within the mantle throughout radioactive decay
• Earths outer liquid core flows and swirls to generate our magnetic field
• The asthenosphere sits between the crust and mantle, a semi - molten weaker zone

Question 5

At constructive plate margins

Answer 5

• As you move away from the core, the pressure is lower — and there’s enough heat to melt the mantle rock (partial melting) — creating magma
• The magma accumulates into magma chambers
• The magma escapes through fractures in the rock (volcanoes)
• As the magma cools, a ridge is formed

Question 6

Ridge - push / slab - pull and sea - floor spreading

Answer 6

• The mid - ocean ridge gets heavy — and slides away / downwards in opposite directions (ridge push)
• At the other end of the plate, there is subduction, pulling the plate down (slab - pull)
• The sea floor spreads as new lava continuously reaches the surface and cold (forming new rocks)