The Theory Of Plate Tectonics - Earth Sciences

Question 1

What does the theory of Plate Tectonics tell us?

Answer 1

The Theory of Plate tectonics tells us that the Earth’s crust is split into plates, which float on the mantle and are moved by convection currents.

Question 2

How did scientist discover that the crust is split into plates?

Answer 2

They used sonar and satellite imaging.

Question 3

Roughly how many plates is the crust split into.

Answer 3

Roughly 30.

Question 4

Why do the plates move?

Answer 4

The plates move because of convection currents.

Question 5

What are convection currents?

Answer 5

Convection currents are when heat causes the partially molten magma to become less dens, and it rises towards the surface. As it gets closer to the surface, it cools, becomes more dense, and falls back down. This creates an arc motion, which pushes against the tectonic plates, forcing them to move.

Question 6

What are the two types of plates that make up the Earth’s crust?

Answer 6

Continental crust and oceanic crust.

Question 7

What are the differences between continental and oceanic crust?

Answer 7

1. Oceanic crust is denser than continental crust
2. Continental crust is thicker than oceanic crust
3. The chemical composition is different
4. Oceanic crust can be recycled in subduction, but continental crust isn’t.