Northern section of the Great Rift Valley. The Sinai Peninsula is in center and the Dead Sea and Jordan River valley above

The Great Rift Valley is a vast geographical and geological feature, approximately 6,000 kilometres (3,700 mi) in length, which runs from northern Syria in Southwest Asia to central Mozambique in East Africa. Caused by the geological process of rifting, it is a complex feature where several plates of the earth's crust join. The rift valley varies in width from thirty to one hundred kilometers, and in depth from a few hundred to several thousand meters. It was named by the explorer John Walter Gregory. From NASA Photo taken during Gemini XI mission. ... From NASA Photo taken during Gemini XI mission. ... Sinai Peninsula, Gulf of Suez (west), Gulf of Aqaba (east) from Space Shuttle STS-40 For other uses of the word Sinai, please see: Sinai (disambiguation). ... The Dead Sea (‎, yam ha-melaħ, Sea of Salt; Quranic Arabic: , baħrᵘ l- mayitⁱ [3], Death Sea) is a salt lake between the West Bank and Israel to the west, and Jordan to the east. ... The Jordan River runs along the border between the West Bank and the Kingdom of Jordan Northern part of the Great Rift Valley as seen from space (NASA) The Jordan River Road sign In spring The Jordan River (Hebrew: נהר הירדן nehar hayarden, Arabic: نهر الأردن nahr al-urdun) is a river in Southwest... “km” redirects here. ... “Miles” redirects here. ...  Southwest Asia in most contexts. ...  Eastern Africa (UN subregion)  East African Community  Central African Federation (defunct)  geographic, including above East Africa or Eastern Africa is the easternmost region of the African continent, variably defined by geography or geopolitics. ... In geology, a rift is a place where the Earths lithosphere is expanding. ... The tectonic plates of the world were mapped in the second half of the 20th century. ... Earth cutaway from core to exosphere. ... African Rift Valley. ... John Walter Gregory (27 January 1864 - 2 June 1932) was a British geologist. ...

Geography

The great rift system extends from Lebanon in the north to Mozambique in the south. The northernmost part of the Rift forms the Beqaa Valley in Lebanon separating the Lebanon Mountains and Anti-Lebanon Mountains. Further south it is known as the Hula Valley separating the Galilee mountains and the Golan Heights. The Jordan River begins here and flows southward through Lake Hula into the Sea of Galilee in Israel, then continues south through the Jordan Valley into the Dead Sea on the Israeli-Jordanian border. From the Dead Sea southwards, the Rift is occupied by the Wadi Arabah, then the Gulf of Aqaba, and then the Red Sea. Beqaa Valley Beqaa (Arabic: البقاع, valley; also transliterated as Bekaa, Biqâ‘ or Becaa) is a fertile valley in east Lebanon. ... Mount Lebanon is the mountain range that extends across the whole country of Lebanon about 160 km (100 mi) parallel to the Mediterranean coast and rising to 3,090 m (10,131 ft). ... Anti-Lebanon is a mountain range of Lebanon and Syria. ... The Hula Valley is an agricultural region in northern Israel with abundant fresh water. ... Galilee (Arabic al-jaleel الجليل, Hebrew hagalil הגליל), meaning circuit, is a large area overlapping with much of the North District of Israel. ... The Golan Heights (‎ Ramat HaGolan, Arabic: Habat al-ūlān) or Golan is a mountainous area in northeastern Israel[1] on the border of Syria, Lebanon, and Jordan. ... The Jordan River runs along the border between the West Bank and the Kingdom of Jordan Northern part of the Great Rift Valley as seen from space (NASA) The Jordan River Road sign In spring The Jordan River (Hebrew: נהר הירדן nehar hayarden, Arabic: نهر الأردن nahr al-urdun) is a river in Southwest... The Hula Valley (Hebrew: emek hahula) is an agricultural region in northern Israel with abundant fresh water. ... The Sea of Galilee or Lake Kinneret (Hebrew ים כנרת), is Israels largest freshwater lake. ... Northern section of the Great Rift Valley. ... The Dead Sea (‎, yam ha-melaħ, Sea of Salt; Quranic Arabic: , baħrᵘ l- mayitⁱ [3], Death Sea) is a salt lake between the West Bank and Israel to the west, and Jordan to the east. ... Cloudbreak over Wadi Araba, Jordan. ... Sinai Peninsula, with the Gulf of Aqaba (east) and the Gulf of Suez (west), as viewed from the Space Shuttle STS-40. ... Location of the Red Sea The Red Sea is an inlet of the Indian Ocean between Africa and Asia. ...

The Jordan Rift Valley from space

The southern end of the Red Sea marks a fork in the rift. The Afar Triangle or Danakil Depression of Ethiopia and Eritrea is the probable location of a triple junction which is possibly underlain by a mantle plume. The Gulf of Aden is an eastward continuation of the rift - before the rift opened, the Arabian Peninsula was attached to the Horn of Africa - and from this point the rift continues as part of the Mid-oceanic ridge of the Indian Ocean. In a southwest direction the fault continues as the Great Rift Valley, which split the older Ethiopian highlands into two halves. Jordan River viewed from space. ... Jordan River viewed from space. ... MODIS satellite image of the Afar Depression and surrounding regions of the Red Sea, Gulf of Aden, Arabia, and the Horn of Africa. ... A triple junction is the point where three tectonic plates diverge. ... A lava lamp illustrates the basic concept of a mantle plume. ... Gulf of Aden in 1860 The Gulf of Aden (Arabic: خليج عدن; transliterated: Khalyj Adan) is located in the Indian Ocean between Yemen on the south coast of the Arabian Peninsula and Somalia in Africa. ... Courtesy USGS The Mid-Atlantic Ridge is an underwater mountain range of the Atlantic Ocean that runs from Iceland to Antarctica, and is the longest mountain range on Earth. ... Ethiopian Highlands with Ras Dashan in the background. ...

In eastern Africa the valley divides into two, the Western Rift and the Eastern Rift Valley. The Eastern Rift Valley is the eastern component of The Great Rift Valley running through Ethiopia, Kenya and Tanzania. ...

The Western Rift, also called the Albertine Rift, is edged by some of the highest mountains in Africa, including the Virunga Mountains, Mitumba Mountains, and Ruwenzori Range. It contains the Rift Valley lakes, which include some of the deepest lakes in the world (up to 1,470 meters deep at Lake Tanganyika). Lake Victoria, the second largest area freshwater lake in the world, is considered part of the Rift Valley system although it actually lies between the two branches. All of the African Great Lakes were formed as the result of the rift, and most lie within its rift valley. Christiaan Toussaint (born on May 20, 1987) and Jurgen Lomp (born on January 23, 1988) are two promosing Tech Trance producers under the name of Virunga. ... Kasulu mountains, Tanzania Category: ... The Ruwenzori Range, now officially called Rwenzori Mountains (the spelling having been changed in about 1980 to conform more closely with the local tribal name) is a small but spectacular mountain range of central Africa, often referred to as Mt. ... This article or section does not cite any references or sources. ... For other uses, see Lake (disambiguation). ... Lake Tanganyika is a large lake in central Africa (3° 20 to 8° 48 South and from 29° 5 to 31° 15 East). ... For other places with the same name, see Lake Victoria (disambiguation). ... The Great Lakes of Africa are a series of lakes in and around the Great Rift Valley. ...

In Kenya the valley is deepest to the north of Nairobi. As the lakes in the Eastern Rift have no outlet to the sea and tend to be shallow they have a high mineral content as the evaporation of water leaves the salts behind. For example, Lake Magadi has high concentrations of soda (sodium carbonate) and Lake Elmenteita, Lake Baringo, Lake Bogoria, and Lake Nakuru are all strongly alkaline, while the freshwater springs supplying Lake Naivasha are essential to support its current biological variety. Nairobi (pronounced ) is the capital and largest city of Kenya. ... For other uses, see Mineral (disambiguation). ... Lake Magadi Lake Magadi is the southermost lake in the Kenyan Rift Valley, lying north east of Lake Natron. ... Sodium carbonate (also known as washing soda or soda ash), Na2CO3, is a sodium salt of carbonic acid. ... Lake Elmenteita is an 18 sq km soda lake, in the eastern part of the Great Rift Valley. ... Lake Baringo is, after Lake Turkana, the most northern of the Great Rift Valley lakes of Kenya, with a surface area of about 130 sq km. ... Lake Borgoria is north of Lake Baringo, Kenya, and is not a fresh water lake. ... Lake Nakuru National Park is 168 km² It is very close to the second largest city in Kenya, Nakuru. ... Location of Naivasha in Kenya Lake Naivasha is a freshwater lake in Kenya, lying north west of Nairobi, outside the town of Naivasha. ...

Map of East Africa showing some of the historically active volcanoes (red triangles) and the Afar Triangle (shaded, center) — a triple junction where three plates are pulling away from one another: the Arabian Plate, and the two parts of the African Plate (the Nubian and the Somalian) splitting along the East African Rift Zone (USGS).

The Rift Valley near Eldoret, Kenya

Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... MODIS satellite image of the Afar Depression and surrounding regions of the Red Sea, Gulf of Aden, Arabia, and the Horn of Africa. ... A triple junction is the point where three tectonic plates diverge. ... Image File history File linksMetadata Size of this preview: 800 × 600 pixel Image in higher resolution (2304 × 1728 pixel, file size: 1. ... Image File history File linksMetadata Size of this preview: 800 × 600 pixel Image in higher resolution (2304 × 1728 pixel, file size: 1. ...

Geothermal activity

The formation of the Rift Valley continues, probably driven by mantle plumes and ultimately a result of the African superswell.^[1] The associated geothermal activity and spreading at the rift has caused the lithosphere to thin from a typical 100 km thickness for continents to a mere 20 km. Though it is common for one arm of a triple junction to fail, if spreading continues the lithosphere may rupture several million years hence, splitting eastern Africa off to form a new landmass. In short, this will lead to the formation of a new mid-ocean ridge. A lava lamp illustrates the basic concept of a mantle plume. ... The African superswell is an extraordinary uplift of the African continent, particularly its southern half; southern Africa on average lies a full kilometer above sea level, with seemingly anomalous uplifts extending well into the south Atlantic ocean. ... The tectonic plates of the Lithosphere on Earth. ... Oceanic Ridge Oceanic crust is formed at an oceanic ridge, while the lithosphere is subducted back into the asthenosphere at trenches. ...

The volcanic activity at this site and unusual concentration of hotspots has produced the volcanic mountains Mount Kilimanjaro, Mount Kenya, Mount Karisimbi, Mount Nyiragongo, Mount Meru and Mount Elgon as well as the Crater Highlands in Tanzania. The Ol Doinyo Lengai volcano remains active, and is currently the only natrocarbonatite^[2] volcano in the world. In geology, a hotspot is a location on the Earths surface that has experienced active volcanism for a long period of time. ... For other uses, see Kilimanjaro (disambiguation). ... Mount Kenya has a low profile typical of a shield volcano. ... Mount Karisimbi is a dormant volcano in the Virunga Mountains of Rwanda. ... Mount Nyiragongo is a volcano in the Virunga Mountains associated with the Great Rift Valley. ... Mount Meru is an active volcano located just 70 kilometers (44 miles) west of Mount Kilimanjaro. ... Mount Elgon is an extinct volcano on the border of Uganda and Kenya. ... Topographical map of the Crater Highlands, looking from southwest to north. ... Ol Doinyo Lengai is a volcano located in Tanzania and is part of the volcanic system of the Great Rift Valley in eastern Africa. ... Cleveland Volcano in the Aleutian Islands of Alaska photographed from the International Space Station For other uses, see Volcano (disambiguation). ... Carbonatites are intrusive igneous rock structures with more than 50% carbonate content, many of which contain distinctive abundances of apatite, magnetite, barite, and fluorite, that may contain economic or anomalous concentrations of rare earth elements, phosphorus, niobium, uranium, thorium, copper, iron, titanium, barium, fluorine, zirconium, and other rare or incompatible...

The island Jabal al-Tair including the basaltic stratovolcano of the same name, is located northwest of the Bab al-Mandab passage at the mouth of the Red Sea, about half way between Yemen and Eritrea. This volcano erupted on 30 September 2007, after 124 years of dormancy. Landsat 7 image of the island Jabal al-Tair Island (Jebel Teir, Jabal al-Tayr, Tair Island, Al-Tair Island, Jazirat at-Tair; Arabic: , literally, Bird Mountain Island) is a roughly oval volcanic island northwest of the constricted Bab al-Mandab passage at the mouth of the Red Sea, about... Bab-el-Mandeb area with description The Bab-el-Mandeb, alternatively Bab el Mandab, Bab al Mandab, or Bab al Mandeb meaning Gate of Tears in Arabic (باب المندب), is the strait separating the continents of Asia (Yemen on the Arabian Peninsula) and Africa (Djibouti, north of Somalia on the Horn of... Location of the Red Sea The Red Sea is an inlet of the Indian Ocean between Africa and Asia. ... is the 273rd day of the year (274th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Towering over the city of Naples, Vesuvius is dormant but certainly not extinct A dormant volcano is a volcano which is not currently erupting, but is believed to still be capable of erupting in the future. ...

Discoveries in human evolution

The Rift Valley has been a rich source of fossils^[3] that allow study of human evolution, especially in an area known as Piedmont.^[4] Because the rapidly eroding highlands have filled the valley with sediments, a favorable environment for the preservation of remains has been created. The bones of several hominid ancestors of modern humans have been found there, including those of "Lucy",^[5] a nearly complete australopithecine skeleton, which was discovered by anthropologist Donald Johanson. Richard and Mary Leakey have also done significant work in this region. // For the history of humans on Earth, see History of the world. ... Genera The hominids are the members of the biological family Hominidae (the great apes), which includes humans, chimpanzees, gorillas, and orangutans. ... Binomial name Johanson & White, 1978 Australopithecus afarensis is an extinct hominid which lived between 3. ... This term australopithecine refers to two very closely related hominin genera: Australopithecus Paranthropus When used alone, the term refers to both genera together. ... Donald Carl Johanson (born June 28, 1943) is an American paleoanthropologist known for his discovery of the skeleton of a 3. ... In 1977, Leaky sat next to the rare Half Monkey Half Man, who took a bite out of him, and made Leaky cry. ... Mary Leakey (February 6, 1913 – December 9, 1996) was a British archaeologist, who, along with others, discovered the first skull of a fossil ape on Rusinga Island and also a noted robust Australopithecine called Zinjanthropus at Olduvai. ...

Further reading

• Africa's Great Rift Valley, 2001, ISBN 0810906023
• Tribes of the Great Rift Valley, 2007, ISBN 9780810994119
• East African Rift Valley lakes, 2006, OCLC 76876862
• Photographic atlas of the Mid-Atlantic Ridge Rift Valley, 1977, ISBN 0387902473
• Rift Valley fever : an emerging human and animal problem, 1982, ISBN 9241700637

Year 2001 (MMI) was a common year starting on Monday (link displays the 2001 Gregorian calendar). ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... Also: 1977 (album) by Ash. ... Year 1982 (MCMLXXXII) was a common year starting on Friday (link displays the 1982 Gregorian calendar). ...

See also

• Graben
• Horst (geology)
• Rift valley

USGS image A graben is a depressed block of land bordered by parallel faults. ... USGS image In physical geography and geology, a horst is the raised fault block bounded by normal faults. ... African Rift Valley. ...

Notes

1. ^ http://72.14.253.104/search?q=cache:SrozakeRnuIJ:www.geo.lsa.umich.edu/~crlb/RESEARCH/PAPERS/CLBSilver98.pdf+%22great+rift+valley%22+-wiki+superswell&hl=en&ct=clnk&cd=12&gl=us accessdate 2007-08-16
2. ^ http://lycos.com/info/great-rift-valley.html accessdate 2007-08-16
3. ^ http://whc.unesco.org/en/tentativelists/1580/ accessdate 2007-08-16
4. ^ http://www.spiritus-temporis.com/great-rift-valley/ accessdate 2007-08-16
5. ^ http://www.ethiopianriftvalleysafaris.com/ accessdate 2007-08-16

External links

• Small simple-coloured map
• Maps from the Albertine Rift Programme