East African Rift
Encyclopedia
Rift
In geology, a rift or chasm is a place where the Earth's crust and lithosphere are being pulled apart and is an example of extensional tectonics....
zone in eastern Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
that appears to be a developing divergent tectonic plate boundary
Divergent boundary
In plate tectonics, a divergent boundary or divergent plate boundary is a linear feature that exists between two tectonic plates that are moving away from each other. Divergent boundaries within continents initially produce rifts which produce rift valleys...
. It is part of the larger Great Rift Valley
Great Rift Valley
The Great Rift Valley is a name given in the late 19th century by British explorer John Walter Gregory to the continuous geographic trench, approximately in length, that runs from northern Syria in Southwest Asia to central Mozambique in South East Africa...
. The rift is a narrow zone in which the African Plate
African Plate
The African Plate is a tectonic plate which includes the continent of Africa, as well as oceanic crust which lies between the continent and various surrounding ocean ridges.-Boundaries:...
is in the process of splitting into two new tectonic plates called the Somali Plate
Somali Plate
The Somali Plate or Somalian Plate is a tectonic plate that is being formed as the African Plate is splitting along the East African Rift. The part of the African Plate which lies on the other side of the rift is sometimes referred to as the Nubian Plate...
and the Nubian Plate, which are subplates or protoplates. It runs from the Afar Triple Junction
Afar Triple Junction
The Afar Triple Junction is a junction of three tectonic rifts centered in the Afar Depression, informally known as the Afar Triangle, of northeastern Africa. Here, the Red Sea Rift meets the Aden Ridge and the East African Rift...
in the Afar Depression
Afar Depression
The Afar Triangle is a geological depression that is caused by the Afar Triple Junction which is part of the Great Rift Valley. It overlaps Eritrea, Djibouti and the entire Afar Region of Ethiopia. The Afar Triangle includes the Danakil Depression and the lowest point in Africa, Lake Asal...
southward through eastern Africa. It is believed to run offshore of the coast of Mozambique along the Kerimba and Lacerda rifts or grabens, terminating in the Andrew Bain Fracture Zone complex, where it is believed to have its junction with the Southwest Indian Ridge
Southwest Indian Ridge
The Southwest Indian Ridge is a divergent tectonic plate boundary located along the floor of the southwest Indian Ocean. It separates the African Plate to the north from the Antarctic Plate to the south....
.
The East African Rift consists of two main branches called the Eastern Rift Valley and the Western Rift Valley. These result from the actions of numerous normal (dip-slip) faults which are typical of all tectonic rift zones.
Volcanic activity
The East African Rift Zone includes a number of active as well as dormant volcanoes. These include Mount KilimanjaroMount Kilimanjaro
Kilimanjaro, with its three volcanic cones, Kibo, Mawenzi, and Shira, is a dormant volcano in Kilimanjaro National Park, Tanzania and the highest mountain in Africa at above sea level .-Geology:...
, Mount Kenya
Mount Kenya
Mount Kenya is the highest mountain in Kenya and the second-highest in Africa, after Kilimanjaro. The highest peaks of the mountain are Batian , Nelion and Point Lenana . Mount Kenya is located in central Kenya, just south of the equator, around north-northeast of the capital Nairobi...
, Mount Longonot
Mount Longonot
Mount Longonot is a dormant stratovolcano located southeast of Lake Naivasha in the Great Rift Valley of Kenya, Africa. It is thought to have last erupted in the 1860s. Its name is derived from the Maasai word oloonong'ot, meaning "mountains of many spurs" or "steep ridges".Mount Longonot is...
, Menengai Crater, Mount Karisimbi
Mount Karisimbi
Mount Karisimbi is an inactive volcano in the Virunga Mountains on the border between Rwanda and the Democratic Republic of Congo. At , Karisimbi is the highest of the eight major mountains of the mountain range, which is a part of the East African Rift Valley...
, Mount Nyiragongo
Mount Nyiragongo
Mount Nyiragongo is a stratovolcano in the Virunga Mountains associated with the Great Rift Valley. It is located inside Virunga National Park, in the Democratic Republic of the Congo, about 20 km north of the town of Goma and Lake Kivu and just west of the border with Rwanda. The main crater...
, Mount Meru
Mount Meru (Tanzania)
Mount Meru is an active stratovolcano located west of Mount Kilimanjaro in the nation of Tanzania. At a height of , it is visible from Mt Kilimanjaro on a clear day, and is the tenth highest mountain in Africa. Much of its bulk was lost about 8,000 years ago due to an eastward volcanic blast,...
and Mount Elgon
Mount Elgon
Mount Elgon is an extinct shield volcano on the border of Uganda and Kenya, north of Kisumu and west of Kitale.- Physical features :It is the oldest and largest solitary volcano in East Africa, covering an area of around 3500 km²....
as well as the Crater Highlands
Crater Highlands
The Crater Highlands are a region along the East African Rift in Tanzania, located in a spreading zone at the intersection of branches of the African and Somali tectonic plates, resulting in distinctive and prominent landforms....
in Tanzania
Tanzania
The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...
. The Ol Doinyo Lengai
Ol Doinyo Lengai
Ol Doinyo Lengai is an active volcano located in the north of Tanzania and is part of the volcanic system of the Great Rift Valley in Eastern Africa. It is located in the eastern Rift Valley, south of both Lake Natron and Kenya. It is unique among active volcanoes in that it produces...
volcano
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
remains active, and is currently the only natrocarbonatite
Natrocarbonatite
Natrocarbonatite is a rare carbonatite lava which erupts from the Ol Doinyo Lengai volcano in Tanzania within the Great Rift Valley of eastern Africa. Whereas most lavas are rich in silicate minerals, the natrocarbonatite lavas of Ol Doinyo Lengai are rich in the rare sodium and potassium carbonate...
volcano in the world. Erta Ale
Erta Ale
Erta Ale is a continuously active basaltic shield volcano in the Afar Region of northeastern Ethiopia, the most active volcano in Ethiopia. It is in the Afar Depression, a badlands desert area spanning the border with Eritrea, and the volcano itself is surrounded completely by an area below sea...
is a continuously active basaltic shield volcano in the Afar Region of northeastern Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...
.
See also
- Baikal Rift ZoneBaikal Rift ZoneThe Baikal Rift Zone is a divergent plate boundary centered beneath Lake Baikal in southeastern Russia. To its west is the Eurasian Plate and to its east is the Amur Plate which is moving away from the rift toward Japan at about 4 mm per year....
- West Antarctic RiftWest Antarctic RiftThe West Antarctic Rift is a major, active rift valley lying between East and West Antarctica. It encompasses the Ross Sea, the area under the Ross Ice Shelf and a part of West Antarctica...
- Northern Cordilleran Volcanic ProvinceNorthern Cordilleran volcanic provinceThe Northern Cordilleran Volcanic Province , formerly known as the Stikine Volcanic Belt, is a geologic province defined by the occurrence of Miocene to Holocene volcanoes in the Pacific Northwest of North America...