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Danakil Depression |
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The Danakil Depression (also
called the Afar Depression or
the Afar Triangle) is a geological depression
in the Horn of Africa, where it overlaps Eritrea, the Afar
Region of Ethiopia, and Djibouti. Afar, especially the Middle
Awash, is well known as one of the cradles of hominids: Lucy,
the fossilized specimen of Australopithecus afarensis,
was found here. The Afar Depression includes the lowest point
in Africa, Lake Asal (−155 meters {−500 ft}).
The climate varies from around 25 °C (77 °F) during
the rainy season (September-March) to 48 °C (118°F)
during the dry season (March-September). It is one of the hottest
places year-round anywhere on Earth. Only the Awash River flows
into the depression, where it ends in a chain of lakes that
increase in salinity. |
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The Afar Depression is a plate tectonic triple junction where
the spreading ridges that are forming the Red Sea and the Gulf
of Aden emerge on land and meet the East African Rift. The
central meeting place for these three pieces of Earth's crust
is around Lake Abbe. The Afar Depression is one of two places
on Earth where a mid-ocean ridge can be studied on land, the
other being Iceland. |
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The Afar, a nascent seafloor spreading
center, is slowly rifting apart at a rate of 1–2 centimeters
(0.3–0.8 in) per year. The immediate consequence
of this is that there are (as of late 2005) a continuous
sequence of earthquakes, fissures hundreds of metres long
and deep appearing in the ground, and the valley floor sinking
as much as 100 metres. Between September and October 2005,
163 earthquakes of magnitudes greater than 3.9 and a volcanic
eruption occurred within the Afar rift. 2.5 cubic kilometers
of molten rock was injected into the plate along a dyke between
depths of 2 and 9 km, forcing open an 8 meter wide gap on
the surface.
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