A hotspot that now lies in the middle of the Atlantic Ocean was once under the Great Lakes, and may explain why they formed ...

A hotspot that is now located in the Atlantic played a key role in forming the lakes, home to a fifth of the world's fresh water.

Instead, volcanoes have formed the long chain of islands because of the "Hawaiian hot spot". A hot spot is made up of super-heated material deep inside the earth, located in the middle of a plate.