The Restless Earth Flashcards
What is the earths crust and upper mantle made up of?
Massive pieces called tectonic plates which are constantly moving
Why do tectonic plates move?
Because of convection currents in the mantle beneath them
What are the convection currents caused by?
Energy released from the decay of radioactive elements heating up the mantle
What happens when plates meet?
A huge force builds up and eventually the rocks give way, changing shape or moving suddenly which causes earthquakes, volcanoes, of mountain formation
What is difficult to predict?
When and where earthquakes will happen
Why can scientists not predict when and where earthquakes will happen?
Because they do not know enough about the earth
What did Alfred Wegener put forward?
The continental drift theory
Why did people not accept Wegener’s ideas?
Because he could not explain why the continents moved, and other scientists thought that instead the earth was shrinking as it cooled
