The Great Rift Valley of

Ethiopia Ethiopia, officially the Federal Democratic Republic of Ethiopia, is a landlocked country located in the Horn of Africa region of East Africa. It shares borders with Eritrea to the north, Djibouti to the northeast, Somalia to the east, Ken ...

, (or Main Ethiopian Rift or Ethiopian Rift Valley) is a branch 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 ...

that runs through

in a southwest direction from the Afar triple junction. In the past, it was seen as part of a "

Great Rift Valley 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 in Asia, through the Red Sea, to Moz ...

" that ran from

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 ...

Syria Syria, officially the Syrian Arab Republic, is a country in West Asia located in the Eastern Mediterranean and the Levant. It borders the Mediterranean Sea to the west, Turkey to Syria–Turkey border, the north, Iraq to Iraq–Syria border, t ...

. Known for its scenery and diverse wildlife in Ethiopia specifically the Rift Valley holds importance in the field of human evolution. It is recognized as an area for researching the stages of human development with crucial fossil findings such, as Lucy (Australopithecus afarensis) unearthed within its bounds.

Description

The Great Rift Valley lies between the Ethiopian Plateau to the north and the Somalia Plateau to the south. The

rift In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben ...

developed as the Nubian and Somali plates began to separate during the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

Period along the East African rift system. Rift initiation was asynchronous along the Ethiopian rift valley: deformation began around 18 million years ago at the south end, around 11 million years ago close to the Afar depression and probably around 6-8 million years ago in the central sector. The rift is extending in an ESE-WNW direction at about annually. The Ethiopian rift valley is about wide and bordered on both margins by large, discontinuous

normal fault In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

s that give rise to major tectonic escarpments separating the rift floor from the surrounding plateaus. These faults are now thought to be inactive at the northern rift valley termination, whereas to the south they are still tectonically and seismically active. The rift floor is cut by a series of smaller en echelon, right-stepping, rift basins of

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...

to recent age. These basins are about wide and long. In the northern part of the rift, extension within the valley is now thought to be mainly along these faulted and

magma Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma (sometimes colloquially but incorrectly referred to as ''lava'') is found beneath the surface of the Earth, and evidence of magmatism has also ...

tically active segments. These segments are considered to be developing mid ocean ridge spreading centers.

Ethiopian Rift Valley lakes

The Ethiopia Rift Valley lakes are the northernmost of the African Rift Valley Lakes. The Ethiopian Rift Valley lakes occupy the floor of the rift valley between the two highlands. Most of the Ethiopian Rift Valley lakes do not have an outlet, and most are

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 ...

. Although the Ethiopian Rift Valley Lakes are of great importance to Ethiopia's economy, as well as being essential to the survival of the local people, there were no intensive and extensive limnological studies undertaken of these lakes until recently. The major ones are *

Lake Abaya Lake Abaya (Amharic: አባያ ሐይቅ) is a lake in the South Ethiopia Regional State of Ethiopia. It is located in the Main Ethiopian Rift, east of the Guge Mountains. The town of Arba Minch lies on its southwestern shore, and the souther ...

(, elevation ), the largest Ethiopian Rift Valley lake * Lake Chamo (, elevation ) * Lake Zway (, elevation ) * Lake Shala (, elevation ), the deepest Ethiopian Rift Valley lake * Lake Koka (, elevation ) * Lake Langano (, elevation ) * Lake Abijatta (, elevation ) * Lake Awasa (, elevation )

References

{{coord missing, Ethiopia Rifts and grabens Great Rift Valley Geology of Ethiopia Volcanoes of Ethiopia