In 10-20 million years the rift will have grown into a new ocean. © Julie Rowland, University of Auckland
By Royal Society University Research Fellow Tim Wright, University of Leeds
Where is the new ocean?
Africa is slowly splitting in two. The rift valley cuts from the Red Sea and Gulf of Aden down through Ethiopia, Kenya and Tanzania, and continues as far as Mozambique. Although this great tear is only widening at about the speed your finger nails grow, in just 10 or 20 million years (a blink of an eye to a geologist) the horn of Africa will have been sliced off, creating a new ocean.
How do oceans form?
New oceans form as tectonic plates pull apart – the forces responsible come from deep within our planet’s hot interior. Although most of the Earth is made of solid rock, it can flow like hot toffee. Massive convection currents result in hot mantle rocks rising in some areas and sinking in others. One area where material is rising is beneath East Africa – this has raised the surface elevation and is causing it to crack apart.
How does this affect the people living in the rift valley?
Although there is no imminent danger of water flooding in, the stretching of the outer layer of the earth causes rocks to melt, and this can produce massive volcanism. This process is happening right now in the Afar region of northern Ethiopia, where an unusual burst of activity has seen 4 eruptions in the last 4 years, as the two tectonic plates have pulled apart by as much as 8 metres - the length of a London Bus.
Is this how all the oceans were created?
Yes - around 60 Million years ago, the same processes were going on in Britain as the supercontinent Pangea was breaking up and the Atlantic Ocean began to open. We can still see the eroded cores of rift volcanoes on Scottish islands such as Skye and Mull.