The African superswell is a region including the Southern and Eastern African plateaus and the Southeastern Atlantic basin where exceptional tectonic uplift has occurred, resulting in terrain much higher than its surroundings. The average elevation of cratons is about 400–500 meters above sea level.[1] Southern Africa exceeds these elevations by more than 500 m, and stands at over 1 km above sea level. The Southern and Eastern African plateaus show similar uplift histories, allowing them to be considered as one topographic unit. When considered this way, the swell is one of the largest topographic anomalies observed on any continent, and spans an area of over 10 million km2. Uplift extends beyond the continents into the Atlantic Ocean, where extremely shallow ocean depths are visible through bathymetric survey. The region can indeed be considered as one large swell because the bathymetric anomaly to the southwest of Africa is on the same order as the topographic anomaly of the plateaus (approximately 500 m).[2]
The superswell is a relatively recent phenomenon, probably beginning between 5 and 30 million years ago.[3]