Gregory’s Great Rift stitches Syria’s valleys to East Africa
The Great Rift Valley, as first defined, links about 6,500 kilometres of depressions from northern Syria’s plains through the Red Sea to Mozambique. John Walter Gregory coined the phrase in 1896 after Eduard Suess imagined one Syria-to-Mozambique system.
Geologists now speak of the Afro-Arabian Rift: the Dead Sea Transform in the north, the Red Sea ridge spreading Nubia from Arabia, then East African branches meeting at the Afar triple junction, where the crust has thinned. The northernmost section is the Ghab Plain on the Orontes in Syria, followed south by Lebanon’s Beqaa valley. The Red Sea’s central trough plunges to 2,860 metres yet is under 60 kilometres wide.
South of the Red Sea the first rift feature is the Danakil Depression inside the Afar, set between the Ethiopian plateau and the Danakil Alps, its floor well below sea level. The Main Ethiopian Rift continues south through uplifted highlands before the valley grows indistinct in a broadly rifted zone.
Farther south it divides. The eastern or Gregory branch begins with the Omo valley in southern Ethiopia, while the western or Albertine branch starts with the Rhino Camp basin and follows Lake Albert, where the Albert Nile passes through. At the southern end lies Lake Malawi, the world’s third-deepest freshwater body at 706 metres, separating Mozambique’s Nyassa plateau from Malawi.
Above the faults runs a sky road: the Rift Valley and Red Sea corridor is the second most important flyway on Earth for migrating soaring birds, used by species such as the European honey buzzard and steppe eagle. Epidemiologists, palaeontologists, and ecologists borrow the name for whichever local stretch they study, as in Rift Valley fever, and a large fissure that opened in Kenya in 2018 drew headlines suggesting East Africa could eventually split in two.
Source: Great Rift Valley
