lesson 4: how does continental drift happen

Question 1

how does continental drift happen

Answer 1

convection currents, sea floor spreading, subductions zones, earthquakes

Question 2

convection currents

Answer 2

• Asthenosphere is a layer of viscous molten rock
• The mantle is able to move around
• Convection currents are caused by heat coming from the centre of the earth
• The heat is radioactive decay happening inside the core
• The decay gives up high amounts of heat energy causing it to heat the mantle
• The liquid particles take up more space, becoming less dense and rises
• The heat causes these particles to move around more
• As the particles rise, they reach the edge of the lithosphere causing them to cool
• This makes the particles denser, and they begin to drop back down lower into the asthenosphere
• These convection currents cause the tectonic plates to move