A single mid-ocean ridge system connects the world's oceans, making the ridge the longest mountain range in the world. On land, giant troughs such as the Great Rift Valley in Africa form where ...

That ridge, it was later discovered, extended through the major oceans of the world. It is now called the Mid-Ocean Ridge ... called the Great Global Rift, came very close to land.

Running along the top of this chain of mountains is a deep crack, called a rift valley ... ocean floor. The speed at which new ocean floor is created varies from one location on the ocean ridge ...