Rifting like this is caused forces deep underground stretching out Earth’s lithosphere layer until it cracks.
Dr Stamps said: “The rate of present-day break-up is millimetres per year, so it will be millions of years before new oceans start to form.
“The rate of extension is faster in the north, so we’ll see new oceans forming there first.”
Dr Stamps and her colleagues collected GPS data along this part of the African continent to map out where the extension is happening.
The East African Rift System stretches for more than 1,800 miles (3,000km) from the Gulf of Aden between Yemen and Somalia, and south towards Zimbabwe.