New ocean may arise as Africa continues to split, scientists predict

Supplied image.

Supplied image.

Published Mar 18, 2023


Johannesburg - It may be a long way off but scientists predict that the African continent could look very different in the future.

Africa could be split into two parts by the formation of a new ocean. Geologists said two major sections of the continent are moving apart, which could eventually result in the creation of a new body of water. Landlocked countries such as Uganda and Zambia could potentially have their own coastlines in millions of years.

The formation of the East African Rift, a 35-mile-long crack in Ethiopia's deserts in 2005, marked the beginning of the creation of a new sea. Seismic data was presented in the peer-reviewed journal, Geophysical Research Letters, demonstrating that the formation of the rift was driven by tectonic processes similar to those occurring at the bottom of the ocean.

The crack was identified as being at the border of three tectonic plates that have already been distancing themselves for some time. Christopher Moore, a doctorate student at the University of Leeds, said: "This is the only place on earth where you can study how a continental rift becomes an oceanic rift. These types of tectonic shifts were also observed in the creation of the Red Sea and the Gulf of Aden between East Africa and Western Asia.“

GPS tracking shows that land movements between these tectonic plates have been continuously occurring at different rates, with the Arabian plate moving away from Africa at a pace of one inch per year. Ken Macdonald, a marine geophysicist and professor emeritus at the University of California, said: "As we get more and more measurements for GPS, we can get a much greater sense of what's going on."

It is predicted that the Red Sea and the Gulf of Aden will flood the Afar region and the East African Rift Valley.

Structural and tectonics geologist at UKZN Dr Mike Watkeys said the rift was observed from the early days of plate tectonics in the 1960s, and before that amongst those that proposed continental drift.

“There is a triple junction between plates in the Afar region (The Afar Region, formerly known as Region 2, is a regional state in northeastern Ethiopia and the homeland of the Afar people) due to a 'hot spot' in the mantle which caused the volcanism that built-up the Ethiopia plateau.This process commenced about 40 million years ago. Three fracture zones radiated away from the hot spot and developed into divergent plate boundaries (boundaries where plates are moving away from each other). The one that propagated northwards developed into the Red Sea. It has a mid-ocean ridge along its length that is producing a new ocean floor as Africa and Arabia move apart,” he said.

Watkeys also believes that it was the North Eastern movement of Arabia that caused the earthquakes in Turkey in February.

“The propagating fracture also developed a mid-ocean ridge and evolved into the Gulf of Yemen as Africa and Arabia separated. The southwards propagating fracture developed into the East African Rift system. Apart from the very northern section in Afar, it is only developed in continental crust. Although there is East-West stretching of the crust, the rift has not developed into a complete divergent plate boundary and is certainly a long way from developing into an ocean (even in geological time),” he added.

Two rifts in the Ethiopia-Kenya region and the Tanzania-Malawi region also resulted in increased volcanic activity in the northern end of Lake Malawi with the most recent volcanism in southern parts of the Western Rift; about 1.5 million years ago.

The tectonic activity has also changed the lives of people in the Goma region in the Democratic Republic of Congo which recorded a volcanic eruption just before the Covid-19 pandemic hit.

And while South Africans have nothing to fear, the continent as we know it will have a different face in years to come.

The Saturday Star