Crack in the surface over the area of Kenya where the African plates are pulling apart. Photo capture: YouTube
Of all the ongoing geological processes, one of the most notorious is a crack of 3,500 kilometers long in East Africa, which is dividing the continent into two parts, which will end up giving rise to a new ocean in between. This crack, called East African Rift, began to form approximately 30 million years ago, due to the rupture of the African plate into two parts: the smaller Somali plate; and the larger Nubian plate.
Map showing the extent of the East African Rift, between the Nubian (left) and Somali (right) plates. The main active volcanoes in the region are also indicated. Image: USGS
In this way, the rupture crosses several countries of the African continent (from south to north): Mozambique, Malawi, Tanzania, Zambia, Burundi, Rwanda, Uganda. the Democratic Republic of the Congo (DRC), Kenya and Ethiopia.
visible break
In much of the East African Rift, you can see gigantic cliffs, evidence of continental separation; and a soil covered with volcanic rocks, evidence of the thinning of the lithosphere (layer of tectonic plates) and the rise of material from the mantle.
Gorge formed in the rift of the East African Rift, in Tanzania. Photo: Ulrich Doering
He volcanism in the rupture is also reflected in the eruptions of Mount Nyiragongo in the DRC and the 16 km lava lake, which emerges from the Erta-Ale volcano, in Ethiopia. Another ‘symptom’ of the divergence process is the activity recurring seismic.
In 2018, a kilometer-long crack opened up on the surface right in the rift zone in southwestern Kenya, causing part of the Nairobi-Narok highway to collapse. Some geologists related it to the separation of plates, but other experts pointed out that the main cause was soil erosion due to rain.
“Doubts remain as to why it formed where it did and whether its appearance is related to the ongoing East African Rift,” said the geologist. Lucia Perez Diaza researcher at the University of Oxford, in an article by The Conversation.
The slow division of Africa
Like any geological process, the division of the African continent will take several million years. To get an idea of how slow this process is, a 2004 study estimated that the Somali and Nubian plates are moving apart at a maximum rate of 7 millimeters per year.
“The rifts are the initial stage of a continental rift and, if successful, can lead to the formation of a new ocean basin. An example of a place on Earth where this has happened is the South Atlantic Ocean, which resulted from the breakup of South America and Africa about 138 million years ago,” Pérez Díaz said.
When the lithosphere in the area of the rift is finished breaking, according to the specialist, the underlying magma will solidify and allow the formation of a new ocean in space created by the separation of the plates.