Africa is gradually pulling apart, a process that will take millions of years to unfold. Over time, a portion of East Africa is expected to separate from the rest of the continent, potentially creating a new sea between the two emerging landmasses.
The enormous fault system currently visible in areas including Ethiopia, Kenya, the Democratic Republic of Congo, Uganda, Rwanda, Burundi, Zambia, Tanzania, Malawi, and Mozambique marks one of the planet’s largest rift structures. What scientists observe is a geologic divide within the African plate, which is splitting into two subplates: the smaller Somali plate and the larger Nubian plate. A study from 2004 notes that these plates are moving apart at a remarkably slow pace, only a few centimeters per year.
Diagrammed in the field of tectonics, the separation hints at the eventual emergence of a broad, island-like region where the Horn of Africa may detach from the main landmass. The current crack system serves as evidence of ongoing divergence between the Somali and Nubian plates.
The result of this long-down process could resemble a wide sea that isolates the Horn from the rest of Africa, forming a distinct geographic entity over tens of millions of years. In time, the area may appear as a substantial landbody, separated from the mainland and bordered by new oceanic features as the sea floor shifts along the crack lines.
In 2018, a striking event underscored the dynamic nature of this rift. On March 18, residents of a small town in southeastern Kenya witnessed the ground opening up in a dramatic fault—a crack several kilometers long and about twenty meters deep. It was a moment unlike anything they had seen before, a vivid illustration of crustal movement in action.
Cross sections from this event highlighted a fault related to the East African Rift, a geologic feature that has been shaping the landscape for millions of years. A geologist from a prominent research group explained that the current activity within the eastern branch of the Rift Valley, which runs through Ethiopia, Kenya, and Tanzania, began with the sudden appearance of a large crack in southwest Kenya. This observation is considered unique for its live demonstration of fracturing stages as they unfold in real time.
The most significant phase of breakage started roughly 30 million years ago in the Afar region of northern Ethiopia and has since propagated southward toward Zimbabwe, at an average rate of about 2.5 to 5 centimeters per year. This slow, persistent movement is the engine behind the ongoing separation of the plates.
Current observations indicate that in the Afar region, the Earth’s lithosphere—the rigid outer shell—has been weakened to near its breaking point. When such a break occurs, a new ocean will begin to form, and within tens of millions of years the seabed is expected to migrate along the entire crack. As a consequence, the African continent could shrink, giving rise to a large island in the Indian Ocean that will include parts of Ethiopia and Somalia, including the Horn of Africa.
These processes, while gradual, are part of a long-term planetary evolution that reshapes continents, oceans, and the boundaries between landmasses. The ongoing study of these faults helps scientists forecast future geological configurations and understand the timeline of major planetary changes. (Source: Royal Holloway College, Dynamic Fault Research Group) (Citation: Current activity along the eastern branch of the Rift Valley, observed and reported by researchers in the field.)