Question

What happens to the polar regions in a Mercator projection?

Answer 1

They become increasingly, and falsely, enlarged.

Explanation:

Any projection of a sphere/spheroid onto a flat surface (e.g pressing a tangerine skin onto a flat kitchen table) is bound to produce some distortion. The question then becomes what should you distort, and by how much, and what consequences that may have.

The Mercator projection has increasingly distorted areas as you move towards the poles (infinite increase in area at the pole itself) as it is a rectangular or cylindrical projection. This means Europe, North America and Australia appear significantly larger than they are in reality. The Peters projection was an alternative proposed in the 70's to overcome this "1st world" bias and makes a fascinating alternative view of the planet on a flat surface.

Recently it has come under fire and this is worth reading once you have got your head around alternative projections.