Each continent of the Earth sits on a ‘floating’ piece of land called a Techtonic plate. These plates ‘float’ on the hot mantle. When two plates ‘float’ apart (diverging plates) there is an ‘oozing’ of hot mantle at the plates edges, as the mantle is cooled by the sea, long mountain ranges are formed. Imagine long mountain ranges with fish swimming around them, just as birds fly around the mountains we see on land.

A mid–ocean ridge or mid–oceanic ridge is an underwater mountain range formed by plate tectonics. This is a seafloor mountain system. The mountains can be as big 2,600 high and yet the whole thing is still under water.