convection currents

Question 1

stages of convection currents

Answer 1

1.Magma (semi-molten rock) near the outer core is heated.
2.As the magma warms it expands, becomes less dense.
3.The less dense magma then starts to rise towards the crust.
4.Magma spreads out and moves the plates with it.
5.As the magma nears the crust it begins to cool.
6.The coolng magma becomes denser and begins to sink, falling closer to the outer core where it gets reheated.
7.The reheated magma becomes less dense and rises again.
8.The rising and falling magma creates circular currents within the mantle.
9.This is known as convection currents.

Question 2

tectonic plate definition

Answer 2

A large piece of the Earth’s crust floating on the mantle.

Question 3

Plate boundary definition

Answer 3

Where 2 or more tectonic plates meet.

Question 4

oceanic plate definition

Answer 4

A tectonic plate that has water on top of it.These are normally heavier/denser.

Question 5

continental plate definition

Answer 5

A tectonic plate that has land on top of it.These are normally lighter/less dense.

Question 6

continental plate density

Answer 6

2.6g/cm cubed-less dense

Question 7

continental plate thickness

Answer 7

30-70km deep-thicker

Question 8

continental plate age

Answer 8

over 1500 million years old-older

Question 9

oceanic plate density

Answer 9

3.0g/cm cubed-denser

Question 10

oceanic plate thickness

Answer 10

6-10km deep-thinner

Question 11

oceanic plate age

Answer 11

less than 200 million years old-younger