Convection Currents

Question 1

What are convection currents?

Answer 1

rising of warm magma and falling of cool magma in the Earth’s mantle causing the plates on the surface to move

Question 2

What are the stages of convection currents moving tectonic plates?

Answer 2

1. heat from the core is conducted to the mantle
2. warm magma becomes less dense and rises
3. at the crust, the magma spreads dragging the plates apart
4. as the magma cools, it’s becomes less dense and sinks, dragging the plate above with it so it subducts below the continental plate

Question 3

What 3 types movement of plates does this cause?

Answer 3

• destructive
• constructive
• conservative

Question 4

Describe a destructive plate boundary with two continental plates.

Answer 4

• plates move towards each other
• large earthquakes
• huge fold mountains

Question 5

Describe constructive plate boundaries.

Answer 5

• plates move away from each other
• oceanic or continental
• small shallow earthquakes
• large shield volcanoes
• oceanic ridges for made of new crust
• whole volcanic islands may form

Question 6

Describe a destructive plate boundary with a oceanic and continental plate.

Answer 6

• plates move towards each other
• oceanic subducted as most dense plate
• large earthquakes
• water, dead sea creatures and sediment subduct with the oceanic plate and are heated by the magma forming CO2, then rises through cracks because of the pressure and creates composite volcanoes
• deep sea ocean trenches, continental volcanic arcs, volcanic island arcs

Question 7

Describe a conservative plate boundary.

Answer 7

• plates move side by side
• oceanic and continental
• large earthquakes
• occurs along ocean ridges