How Africa may become Earth’s next ocean basin in 5 to 10 million years giving birth to a new ocean |

The Afar region in northeastern Africa represents one of the few locations on Earth where a new ocean may be forming over the next several million years. Situated at a unique triple junction where the Red Sea, Gulf of Aden, and East African Rift converge, Afar offers scientists a rare opportunity to observe the processes of continental break-up and ocean genesis in action. The region’s landscape is marked by deep rift valleys, volcanic plateaus, and extensive fissures, reflecting the dynamic forces reshaping the Earth’s crust. Early magnetic surveys conducted in 1968 first mapped anomalies beneath the surface, revealing hidden structures shaped by both past and ongoing tectonic and magmatic activity. When combined with historical measurements from the surrounding Red Sea and Gulf of Aden, these data allow researchers to trace the evolution of rift structures, magmatic pathways, and crustal blocks, providing insights into how continental crust may gradually transform into oceanic crust and eventually give rise to a new ocean in this geologically active region.

The 1968 aeromagnetic survey in Afar measured the Total Magnetic Intensity across southern and central parts of the region, providing a rare glimpse into subsurface geological features. The survey identified linear magnetic anomalies extending over 100 kilometres, many of which ran east-west and intersected the main northeast-southwest trending rift. In northern Afar, anomalies showed deviations of approximately thirty degrees from the Red Sea’s axial trend, suggesting a complex interaction between older tectonic structures and more recent volcanic intrusions. Regions near the Erta Ale volcanic complex exhibited strong magnetic signals, indicating repeated magma movement over millions of years. These anomalies helped map crustal blocks, rift pathways, and zones of magmatic activity, highlighting the intricate architecture of a rift that could eventually open into a new ocean basin.

A recent study published in Journal of African Earth Sciences has digitised the 1968 Afar survey and integrated it with historical magnetic data from the Red Sea and Gulf of Aden to produce detailed Total Magnetic Intensity and first vertical derivative maps. This integration revealed significant variation in the alignment of magnetic anomalies across the region. In southern Afar, anomalies tended to run almost perpendicular to major rift zones, whereas in areas such as the Gulf of Tadjura, anomalies closely aligned with fault structures. These patterns indicate multiple phases of rifting, where early Miocene magmatic activity left enduring magnetic traces that were later modified by subsequent volcanic events. By combining these datasets, researchers can reconstruct the complex tectonic history of Afar and understand how these early rifting events set the stage for continental break-up and eventual ocean formation.

The distribution of magnetic anomalies in Afar offers valuable insight into both ancient and ongoing tectonic processes. Cross-rift anomalies observed throughout the East African Rift and the Red Sea reflect repeated episodes of crustal extension and magma intrusion over geological time. The orientation of anomalies relative to older tectonic features suggests that initial rifting influenced the pathways of later magmatic flows, guiding subsequent intrusions and shaping volcanic activity. By analysing these patterns, scientists can differentiate between crustal blocks formed during early break-up and areas altered by later volcanic activity. This analysis provides a window into the mechanisms that transform continental crust into oceanic crust and explains how Afar’s geological evolution may ultimately lead to the opening of a new ocean basin in the coming millions of years.

Integrating Afar’s 1968 survey data with regional measurements positions the area as a natural laboratory for studying the formation of new ocean basins. Misalignments between magnetic anomalies and surface rift structures highlight the non-linear and episodic nature of continental break-up, while persistent anomalies reveal the long-term imprint of earlier tectonic and magmatic events. Detailed mapping of these structures allows scientists to reconstruct the sequence and timing of rifting processes, offering insight into crustal deformation, magma distribution, and the evolution of triple junctions. By observing these processes in real time, Afar provides a unique opportunity to understand how rift systems progress from continental extension to the eventual birth of a new ocean.

Magnetic trends in southern Afar closely mirror those of the Gulf of Aden, whereas northern anomalies diverge from the Red Sea axis, indicating significant spatial variability in rift development across the region. Comparative analysis with surveys from Djibouti and southeastern Yemen confirms continuity in tectonic and magmatic processes, demonstrating that Afar’s structural complexity is part of a larger, interconnected network of rift systems stretching across northeastern Africa. These correlations provide critical constraints for geophysical models of continental break-up, helping scientists predict how future ocean basins may form. By linking Afar with neighbouring tectonic systems, researchers gain a broader perspective on the forces shaping the region and on the gradual processes that will eventually create Earth’s next ocean.Also Read | Could scientists really have spotted ‘dark matter’ in the Milky Way? Know the truth