ONE of the most surprising things about our planet, to anyone who has sat on the beach and watched the ocean breakers roll in, is just how insignificant a puddle even the greatest ocean is. Even the floors of the deepest ocean trenches lie only 11 kilometres below the sea’s surface, and the average depth of the ocean is just 3.7 kilometres.
Oceans really are very shallow puddles indeed. The North Atlantic, for example, averages a depth of 3 kilometres, and is about 4800 kilometres wide. For a 5-metre wide puddle to have the same proportions, it would have to…
