Great Rift Valley

The Great Rift Valley is a long and important natural feature that stretches for about 6,500 kilometres or 4,000 miles. It runs from the plains of northern Syria through the Red Sea and all the way down to Mozambique in the south. This area is made up of a series of valleys and depressions, which are low areas compared to the land around them.

Scientists in many areas, such as geography, animal studies, and the study of very old life, still use the name Great Rift Valley. However, in the science of how the Earth changes, many experts now prefer to call it the Afro-Arabian Rift System. This name describes the natural processes that created the valleys and mountains in this region.

The name Great Rift Valley was first used by a British geologist named John Walter Gregory in 1896. He built on the earlier ideas of another scientist, Austrian geologist Eduard Suess, who had suggested that these linked features might exist stretching from Syria to Mozambique.

Geology

The Afro-Arabian Rift is a group of important geological features that created the Great Rift Valley. In the north, it starts at the Dead Sea Transform, which is the boundary between the Arabian and African plates. This area stretches from southeastern Turkey down to the Gulf of Aqaba.

The Red Sea Rift is a mid-ocean ridge where the Nubian and Arabian plates are moving apart. It connects to the East African Rift system at the Afar triple junction. The East African Rift continues south through Ethiopia and then splits into two parts that meet again north of Lake Malawi. These rifts are linked with volcanic activity and the formation of deep basins.

Geography

The Great Rift Valley is a long, winding series of valleys and depressions that stretches about 6,500 kilometres from northern Syria all the way down to Mozambique. It passes through many countries and features a variety of landscapes, including rivers, lakes, and mountains.

The northern part of the Great Rift Valley begins in Syria and runs down through the Red Sea. It includes areas like the Ghab Plain in Syria and the Jordan Rift Valley, which contains the Sea of Galilee and the Dead Sea. Further south, the valley continues through Ethiopia and Kenya, where it is often called the Kenya Rift Valley. This area has many lakes and volcanoes, including Lake Bogoria and Mount Kilimanjaro, one of Africa's highest peaks.

In East Africa, the Great Rift Valley splits into two branches. The eastern branch runs through Kenya and into Tanzania, while the western branch includes lakes such as Lake Albert and Lake Tanganyika. The valley ends in southern Africa, near Lake Malawi in Mozambique, where it continues as the Urema Valley.

Asian section

The northernmost part of the Great Rift Valley begins at the Ghab Plain, formed above the Ghab basin, along the Orontes River in northern Syria. Moving south, the Beqaa valley lies next, containing two rivers: the Orontes, which flows north, and the Litani, which flows southwest. At the valley's southern end, the Litani river turns west and comes close to the Hisbai river, part of the Jordan river's headwaters. Beyond this, the Jordan Rift Valley continues down to the Red Sea. The Hula valley is a flat valley at about 70 metres above sea level, bordered by various landscapes including the Golan heights and Naftali mountains. The Jordan river flows through this area into the Sea of Galilee, the northernmost part of the Dead Sea depression, much of which lies below sea level. The Dead Sea occupies the deepest part of this depression, with the Sea of Galilee also sitting in a deep spot. The area between the Dead Sea and the Gulf of Aqaba is known as Arabah. The Gulf of Aqaba itself is a narrow gulf extending from the southern end of Arabah to the Straits of Tiran, connecting to the Red Sea. It includes deep underwater areas such as the Aragonese deep, which reaches 1,850 metres below the surface.

Red Sea

The Asian and African sections of the Great Rift Valley are connected by the Red Sea. Directly south of the Red Sea, the first part of the Great Rift Valley is the Danakil Depression within the Afar Depression, situated between the Ethiopian plateau and the Danakil Alps. The deepest part of this depression lies well below sea level, about 120 metres down in the north. Further south, volcanic activity becomes more visible around the Erta Ale Range. The next clear section is the Main Ethiopian Rift (MER) valley, bordered by the Ethiopian and Somalian plateaus, running northeast to southwest and divided into northern, central, and southern parts. The northern MER extends from the Afar Depression to Lake Koka and features strong volcanic activity. The central section continues to Lake Awasa, and the southern section reaches the "broadly rifted zone." Here, the valley floor rises to about 1,700 metres before gently descending.

In the "broadly rifted zone," the Great Rift Valley becomes less clear. Further south, it divides into two branches: the western (Albertine) rift and the eastern (Gregory) rift. The eastern branch starts with the valley of the Omo river in southern Ethiopia and Lake Turkana in Kenya, often called the Kenya Rift Valley. This area includes several lakes and many volcanoes, some of which are salty, like Lake Bogoria and Lake Natron. The eastern branch continues into Tanzania, spreading out in an area known as the "North Tanzanian Divergence," with rift structures extending southwest to Lake Eyasi, south to Lake Manyara, and southeast to the Pangani River basin. Large volcanoes such as Mount Kenya and Mount Kilimanjaro rise near the rift shoulders. Many national parks protect these lakes and volcanoes, including the Lake Baringo National Park, the Lake Nakuru National Park, and the Mount Kenya National Park.

The western branch of the Great Rift Valley begins with the Rhino Camp basin and continues along Lake Albert. The Albert River, part of the White Nile, flows through this area and the Rhino Camp basin. This branch features a series of deep lakes: Lake Albert, Lake Rutanzige, Lake Kivu, Lake Tanganyika, and Lake Rukwa. Among these, only Rukwa is a closed lake with alkaline water, while the others allow water to flow through. Lake Tanganyika is the world's second-largest and second-deepest freshwater lake. High mountains border this western branch, including the Virunga Mountains, Mitumba Mountains, and Ruwenzori Range. Many national parks protect this region, such as Virunga National Park in the Democratic Republic of Congo, Rwenzori National Park and Queen Elizabeth National Park in Uganda, and Volcanoes National Park in Rwanda.

The southernmost part of the Great Rift Valley includes Lake Malawi, the world's third-deepest freshwater lake, which separates the Nyassa plateau of northern Mozambique from Malawi. The rift continues south as the valley of the Shire River, flowing from Lake Malawi into the Zambezi River. Beyond the Zambezi, the rift valley extends into central Mozambique as the Urema Valley.

Ornithology

The Great Rift Valley and the Red Sea are very important paths for birds that travel long distances. Many birds, like the European honey buzzard, Steppe eagle, Common buzzard, Lesser spotted eagle, White Stork, and Great White Pelican, use this route to move between different places. This path is one of the most important in the world for these flying animals.

Other uses

The term "Great Rift Valley" is also used in many areas of study like epidemiology, paleontology, archaeology, ecology, and zoology. For example, scientists might use it when talking about Rift Valley fever or when studying animals and plants in that area. Each field focuses on the part of the Great Rift Valley that is most important for their work.