The Great Rift Valley () is a series of contiguous geographic depressions, approximately 6,000 or in total length, the definition varying between sources, that runs from the southern Turkish

Hatay Province Hatay Province (, ) is the southernmost province and metropolitan municipality of Turkey. Its area is , and its population is 1,686,043 (2022). It is situated mostly outside Anatolia, along the eastern coast of the Levantine Sea. The province ...

in Asia, through the

Red Sea The Red Sea is a sea inlet of the Indian Ocean, lying between Africa and Asia. Its connection to the ocean is in the south, through the Bab-el-Mandeb Strait and the Gulf of Aden. To its north lie the Sinai Peninsula, the Gulf of Aqaba, and th ...

, to

Mozambique Mozambique, officially the Republic of Mozambique, is a country located in Southeast Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west, and Eswatini and South Afr ...

in Southeast Africa. While the name remains in some usages, it is rarely used in

geology Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth ...

where the term "Afro-Arabian Rift System" is preferred. This valley extends southward from

Western Asia West Asia (also called Western Asia or Southwest Asia) is the westernmost region of Asia. As defined by most academics, UN bodies and other institutions, the subregion consists of Anatolia, the Arabian Peninsula, Iran, Mesopotamia, the Armenian ...

into the eastern part of Africa, where several deep, elongated lakes, called ribbon lakes, exist on the rift valley floor,

Lake Malawi Lake Malawi, also known as Lake Nyasa in Tanzania and Lago Niassa in Mozambique, () is an African Great Lakes, African Great Lake and the southernmost lake in the East African Rift system, located between Malawi, Mozambique and Tanzania. It is ...

and

Lake Tanganyika Lake Tanganyika ( ; ) is an African Great Lakes, African Great Lake. It is the world's List of lakes by volume, second-largest freshwater lake by volume and the List of lakes by depth, second deepest, in both cases after Lake Baikal in Siberia. ...

being two such examples. The region has a unique ecosystem and contains a number of Africa's wildlife parks. Great_rift_valley

The term Great Rift Valley is most often used to refer to the valley of the

East African Rift The East African Rift (EAR) or East African Rift System (EARS) is an active continental rift zone in East Africa. The EAR began developing around the onset of the Miocene, 22–25 million years ago. It was formerly considered to be part of a l ...

, the divergent plate boundary which extends from the Afar triple junction southward through

eastern Africa East Africa, also known as Eastern Africa or the East of Africa, is a region at the eastern edge of the Africa, African continent, distinguished by its unique geographical, historical, and cultural landscape. Defined in varying scopes, the regi ...

, and is in the process of splitting the African plate into two new and separate plates. Geologists generally refer to these evolving plates as the Nubian plate and the Somali plate.

Theoretical extent

Today these rifts and faults are seen as distinct, although connected. Originally, the Great Rift Valley was thought to be a single feature that extended from

Lebanon Lebanon, officially the Republic of Lebanon, is a country in the Levant region of West Asia. Situated at the crossroads of the Mediterranean Basin and the Arabian Peninsula, it is bordered by Syria to the north and east, Israel to the south ...

in the north to

in the south, where it constitutes one of two distinct physiographic provinces of the East African mountains. It included what today is called the Lebanese section of the

Dead Sea Transform The Dead Sea Transform (DST) fault system, also sometimes referred to as the Dead Sea Rift, is a series of Fault (geology), faults that run for about 1,000 km from the Marash triple junction (a junction with the East Anatolian Fault in south ...

(Turkey to

Straits of Tiran The Straits of Tiran ( ') are the narrow sea passages between the Sinai Peninsula, Sinai and Arabian Peninsula, Arabian peninsulas that connect the Gulf of Aqaba and the Red Sea. The distance between the two peninsulas is about . The Multinatio ...

), the

Jordan Rift Valley The Jordan Rift Valley, also Jordan Valley ( ''Bīqʿāt haYardēn'', Al-Ghor or Al-Ghawr), is an elongated endorheic basin located in modern-day Israel, Jordan and the West Bank, Palestine. This geographic region includes the entire length o ...

(geographic term for section including entire course of the

Jordan River The Jordan River or River Jordan (, ''Nahr al-ʾUrdunn''; , ''Nəhar hayYardēn''), also known as ''Nahr Al-Sharieat'' (), is a endorheic river in the Levant that flows roughly north to south through the Sea of Galilee and drains to the Dead ...

, the

Dead Sea The Dead Sea (; or ; ), also known by #Names, other names, is a landlocked salt lake bordered by Jordan to the east, the Israeli-occupied West Bank to the west and Israel to the southwest. It lies in the endorheic basin of the Jordan Rift Valle ...

, and the

Arabah The Arabah/Araba () or Aravah/Arava () is a loosely defined geographic area in the Negev Desert, south of the Dead Sea basin, which forms part of the border between Israel to the west and Jordan to the east. The old meaning, which was in use ...

Valley), Red Sea Rift, and the

. These rifts and faults are considered to having been formed 35 million years ago.

Asia

The northernmost part of the Rift corresponds to the central section of what is today called the

(DST) or Rift. This midsection of the DST forms the

Beqaa Valley The Beqaa Valley (, ; Bekaa, Biqâ, Becaa) is a fertile valley in eastern Lebanon and its most important farming region. Industry, especially the country's agricultural industry, also flourishes in Beqaa. The region broadly corresponds to th ...

in Lebanon, separating the Mount Lebanon range from the Anti-Lebanon Mountains. Further south it is known as the Hula Valley separating the

Galilee Galilee (; ; ; ) is a region located in northern Israel and southern Lebanon consisting of two parts: the Upper Galilee (, ; , ) and the Lower Galilee (, ; , ). ''Galilee'' encompasses the area north of the Mount Carmel-Mount Gilboa ridge and ...

mountains and the

Golan Heights The Golan Heights, or simply the Golan, is a basaltic plateau at the southwest corner of Syria. It is bordered by the Yarmouk River in the south, the Sea of Galilee and Hula Valley in the west, the Anti-Lebanon mountains with Mount Hermon in t ...

. The

begins here and flows southward through Lake Hula into the

Sea of Galilee The Sea of Galilee (, Judeo-Aramaic languages, Judeo-Aramaic: יַמּא דטבריא, גִּנֵּיסַר, ), also called Lake Tiberias, Genezareth Lake or Kinneret, is a freshwater lake in Israel. It is the lowest freshwater lake on Earth ...

Israel Israel, officially the State of Israel, is a country in West Asia. It Borders of Israel, shares borders with Lebanon to the north, Syria to the north-east, Jordan to the east, Egypt to the south-west, and the Mediterranean Sea to the west. Isr ...

. The Rift then continues south through the

into the

, on the

Jordan Jordan, officially the Hashemite Kingdom of Jordan, is a country in the Southern Levant region of West Asia. Jordan is bordered by Syria to the north, Iraq to the east, Saudi Arabia to the south, and Israel and the occupied Palestinian ter ...

ian border. From the Dead Sea southwards, the Rift is occupied by the Wadi

, then the Gulf of Aqaba, and then the

. Off the southern tip of Sinai in the Red Sea, the

meets the Red Sea Rift which runs the length of the Red Sea. The Red Sea Rift comes ashore to meet the

and the Aden Ridge, in the Afar Depression of East Africa. The junction of these three rifts is called the Afar triple junction.

Africa

The East African Rift follows the Red Sea to the end before turning inland into the

Ethiopian highlands The Ethiopian Highlands (also called the Abyssinian Highlands) is a rugged mass of mountains in Ethiopia in Northeast Africa. It forms the largest continuous area of its elevation in the continent, with little of its surface falling below , whil ...

, dividing the country into two large and adjacent but separate mountainous regions. In Kenya, Uganda, and the fringes of South Sudan, the Great Rift runs along two separate branches that are joined to each other only at their southern end, in Southern

Tanzania Tanzania, officially the United Republic of Tanzania, is a country in East Africa within the African Great Lakes region. It is bordered by Uganda to the northwest; Kenya to the northeast; the Indian Ocean to the east; Mozambique and Malawi to t ...

along its border with

Zambia Zambia, officially the Republic of Zambia, is a landlocked country at the crossroads of Central Africa, Central, Southern Africa, Southern and East Africa. It is typically referred to being in South-Central Africa or Southern Africa. It is bor ...

. The two branches are called the Western Rift Valley and the Eastern Rift Valley. The Western Rift, also called the Albertine Rift, is bordered by some of the highest mountains in Africa, including the Virunga Mountains, Mitumba Mountains, and Ruwenzori Range. It contains the

Rift Valley lakes The Rift Valley lakes are a series of lakes in the East African Rift valley that runs through eastern Africa from Ethiopia in the north to Malawi in the south, and includes the African Great Lakes in the south. These include some of the world's ...

, which include some of the deepest lakes in the world (up to deep at

). Much of this area lies within the boundaries of national parks, such as

Virunga National Park Virunga National Park is a national park in the Albertine Rift Valley in the eastern part of the Democratic Republic of the Congo. It was created in 1925. In elevation, it ranges from in the Semliki River valley to in the Rwenzori Mountains. ...

in the

Democratic Republic of Congo The Democratic Republic of the Congo (DRC), also known as the DR Congo, Congo-Kinshasa, or simply the Congo (the last ambiguously also referring to the neighbouring Republic of the Congo), is a country in Central Africa. By land area, it is t ...

, Rwenzori National Park and

Queen Elizabeth National Park Queen Elizabeth National Park is a national park in the Western Region, Uganda, Western Region of Uganda. Location Queen Elizabeth National Park (QENP) spans the districts of Kasese District, Kasese, Kamwenge District, Kamwenge, Rubirizi Distri ...

in Uganda, and Volcanoes National Park in

Rwanda Rwanda, officially the Republic of Rwanda, is a landlocked country in the Great Rift Valley of East Africa, where the African Great Lakes region and Southeast Africa converge. Located a few degrees south of the Equator, Rwanda is bordered by ...

Lake Victoria Lake Victoria is one of the African Great Lakes. With a surface area of approximately , Lake Victoria is Africa's largest lake by area, the world's largest tropics, tropical lake, and the world's second-largest fresh water lake by surface are ...

is considered to be part of the rift valley system although it actually lies between the two branches. All of the

African Great Lakes The African Great Lakes (; ) are a series of lakes constituting the part of the Rift Valley lakes in and around the East African Rift. The series includes Lake Victoria, the second-largest freshwater lake in the world by area; Lake Tangan ...

were formed as the result of the rift, and most lie in territories within the rift. In

Kenya Kenya, officially the Republic of Kenya, is a country located in East Africa. With an estimated population of more than 52.4 million as of mid-2024, Kenya is the 27th-most-populous country in the world and the 7th most populous in Africa. ...

, the valley is deepest to the north of

Nairobi Nairobi is the Capital city, capital and largest city of Kenya. The city lies in the south-central part of Kenya, at an elevation of . The name is derived from the Maasai language, Maasai phrase , which translates to 'place of cool waters', a ...

. As the lakes in the Eastern Rift have no output to the sea and tend to be shallow, they have a high

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Mi ...

content as the evaporation of water leaves the salts behind. For example, Lake Magadi has high concentrations of soda (

sodium carbonate Sodium carbonate (also known as washing soda, soda ash, sal soda, and soda crystals) is the inorganic compound with the formula and its various hydrates. All forms are white, odourless, water-soluble salts that yield alkaline solutions in water ...

) and

Lake Elmenteita Lake Elmenteita is a soda lake, in the Great Rift Valley, about 120 km northwest of Nairobi, Kenya. Geography Elmenteita is derived from the Maasai word , meaning "dust place", a reference to the dryness and dustiness of the area, esp ...

, Lake Bogoria, and Lake Nakuru are all strongly

alkaline In chemistry, an alkali (; from the Arabic word , ) is a basic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The ...

, while the freshwater springs supplying

Lake Naivasha Lake Naivasha is a freshwater lake in Kenya, outside the town of Naivasha in Nakuru County, which lies north west of Nairobi. It is situated in the Great Rift Valley. The name derives from the local Maasai name ''ɛnaɨpɔ́sha '', meaning ...

are essential to support its current biological variety. The southern section of the Rift Valley includes

, the third-deepest freshwater body in the world, which reaches in depth and separates the Nyassa plateau of Northern Mozambique from Malawi. The rift extends southwards from Lake Malawi as the valley of the

Shire River The Shire is the largest river in Malawi. It is the only outlet of Lake Malawi and flows into the Zambezi River in Mozambique. Its length is . The upper Shire River issues from Lake Malawi and runs approximately before it enters shallow Lake Malo ...

, which flows from the lake into the

Zambezi The Zambezi (also spelled Zambeze and Zambesi) is the fourth-longest river in Africa, the longest east-flowing river in Africa and the largest flowing into the Indian Ocean from Africa. Its drainage basin covers , slightly less than half of t ...

River. The rift continues south of the Zambezi as the Urema Valley of central Mozambique.Steinbruch, Franziska (2010). Geology and geomorphology of the Urema Graben with emphasis on the evolution of Lake Urema, ''Journal of African Earth Sciences'', Volume 58, Issue 2, 2010, Pages 272-284. ISSN 1464-343X, https://doi.org/10.1016/j.jafrearsci.2010.03.007.

References

External links

Article on geology.com
* {{Authority control Great Rift Valley, * Rifts and grabens Landforms of Israel Landforms of Syria Landforms of Egypt Landforms of Lebanon Landforms of Ethiopia Landforms of Kenya Landforms of Saudi Arabia Landforms of Yemen Landforms of Tanzania Landforms of the Democratic Republic of the Congo Landforms of Uganda Landforms of Burundi Geology of Israel Geology of Syria Geology of Egypt Geology of Lebanon Geology of Ethiopia Geology of Kenya Geology of Saudi Arabia Geology of Yemen Geology of Tanzania Geology of the Democratic Republic of the Congo Geology of Uganda Geology of Burundi Physiographic provinces Prehistoric Afar Triangle

Theoretical extent

Asia

Africa

See also

References

Further reading

External links