Why is the earth divided into continents?

Question

Why is the earth divided into continents?

Answer 1

Plate tectonics. The surface of the earth is made up of seven major plates and several dozen minor ones, which are basically thick slabs of solid rock moved around by convection currents in the molten rocks below. 300 million years ago the continents were grouped together into one lump, a "supercontinent", which we refer to as "Pangea", and which eventually broke apart into the continents we know today. Pangea wasn't the first supercontinent though - there is evidence showing the Earth goes through cycles of continents drifting apart then colliding again as they move around the globe.

Answer 2

Because it is

Answer 3

Rock formed in differing places on the surface rather than in one concentrated mass, which is hardly surprising, and, after their formation, the resultant plates have been drifting around in a fairly random manner.

Answer 4

tigerstar0000 gives a pretty good account; however, the super continent Pangaea existed about 200 million years, by which time the Euramerica landmass and the Asian landmass had joined the balance.