A huge crack in Kenya could mean the continent will break up
A large crack, stretching several miles, made a sudden appearance recently in south-western Kenya. The tear, which continues to grow, caused part of the Nairobi-Narok highway to collapse and was accompanied by seismic activity in the area.
Now researchers are claiming that in millions of years the African continent could split two.
The East African Rift Valley stretches over 3,000km from the Gulf of Aden in the north towards Zimbabwe in the south, splitting the African plate into two unequal parts: the Somali and Nubian plates.
Activity along the eastern branch of the rift valley, running along Ethiopia, Kenya and Tanzania, became evident when the large crack suddenly appeared in south-western Kenya.
When the lithosphere is subject to a horizontal extensional force it will stretch, becoming thinner. Eventually, it will rupture, leading to the formation of a rift valley.
This process is accompanied by surface manifestations along the rift valley in the form of volcanism and seismic activity.
Rifts are the initial stage of a continental break-up and, if successful, can lead to the formation of a new ocean basin. Continental rifting requires the existence of extensional forces great enough to break the lithosphere.
The East African Rift is described as an active type of rift, in which the source of these stresses lies in the circulation of the underlying mantle.
Beneath this rift, the rise of a large mantle plume is doming the lithosphere upwards, causing it to weaken as a result of the increase in temperature, undergo stretching and breaking by faulting.
Eventually, over a period of tens of millions of years, seafloor spreading will progress along the entire length of the rift.
The ocean will flood in and, as a result, the African continent will become smaller and there will be a large island in the Indian Ocean composed of parts of Ethiopia and Somalia, including the Horn of Africa.
Dramatic events, such as sudden motorway-splitting faults or large catastrophic earthquakes may give continental rifting a sense of urgency but, most of the time, it goes about splitting Africa without anybody even noticing.
Source: The Daily Mail
