The Afar Triangle (or the Afar- Dallol-or the Danakil-Depression)
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 (155 metres below sea level),
lies in Djibouti. Only the Awash River flows into the area, where
it ends in a chain of lakes that increase in salinity.
The Awash River, flowing north-eastward through southern Afar, provides
a narrow green belt and enables life for
the flora and fauna in the area and for the Afars, the nomadic people
living in the Danakil desert.
The lowlands of the Afar Depression are affected by heat and drought.
There is no rain for most of the year, and yearly
rainfall averages range from 100 to 200 millimetres (4 to 7 in), with
less rain falling closer to the coast.
Dallol (upper north) is also part of the depression, one of the hottest
places year-round anywhere on Earth. 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).
About 128 kilometres (80 mi) from the Red Sea, the Awash ends in a
chain of salt lakes, where its water evaporates
as quickly as it is supplied. About 1,200 km2 (460 sq mi) of the Afar
Depression is covered by salt, and salt mining is
still a major source of income for many Afar tribes.
See
Nabro volcano.
Perspective
image of the Afar Depression
http://en.wikipedia.org/wiki/File:AfarDrape.jpg
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Beisa Oryx (Oryx gazella beisa), side view, Samburu National
Reserve, Kenya.
Common Beisa Oryx (Oryx beisa beisa) found in steppe and semi-desert
throughout
the Horn of Africa and north of the Tana River
Photo:ChrisHodgesUK
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The
Afar Depression biome is characterized as desert scrubland. Vegetation
is mostly confined to drought-resistant plants
such as small trees (e.g. species of the dragon tree), shrubs, and
grasses. Wildlife includes many herbivores such as
Grevy's Zebra, Soemmering’s
Gazelle, Oryx Beisa (picture above) and, notably, the last viable
population of
African wild ass, Equus africanus somalicus, (picture below.).
Somali
Wild Ass (Equus africanus somalicus) in captivity at San Diego Zoo,
San Diego, California, USA.
Photographed on 3 June 2002
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Archer's
lark, Heteromirafra archeri
There have been no confirmed sightings of this species since
1955 despite some recent searches, suggesting
that it now has an extremely small population and range. These
are likely to be declining, owing to ongoing
habitat degradation. For these reasons it is classified as
Critically Endangered. It is probably still extant because
the lack of records is likely to be partly a consequence of
its secretive habits and the fairly restricted nature
of recent surveys.
BirdLife International
(2011) Species factsheet: Heteromirafra archeri.
Downloaded from http://www.birdlife.org on 31/12/2011. |
Birds
include the ostrich, the endemic Archer's lark, Heteromirafra
archeri, (picture above) the Secretary Bird,
Arabian and Kori bustards, Abyssinian Roller and Crested Francolin
(picture below). In the southern part of the plain,
in Ethiopia, lies the Mille-Sardo Wildlife Reserve (established
1973).
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Crested
Francolin, Francolinus sephaena, at Kruger National
Park, South Africa
Photo:
Dick Daniels (http://carolinabirds.org/)
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A
bird singing. Paraa Lodge, Murchison Falls NP, Uganda (ssp
grantii).
Recorded 29 August
2006
http://www.youtube.com/watch?v=9bTqqWr_VtU
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The Crested Francolin, Dendroperdix
sephaena, is a species of bird in the Phasianidae family. It
is found in Angola,
Botswana, Democratic Republic of the Congo, Ethiopia, Kenya, Malawi,
Mozambique, Namibia, Somalia,
South Africa, Sudan, Swaziland, Tanzania, Uganda, Zambia, and Zimbabwe.
The
Afar Depression is the product of a tectonic triple junction (the
Afar Triple Junction), where the spreading ridges
that form 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.
In the Depression, the Earth's crust is slowly rifting apart at
a rate of 1–2 centimetres (0.4–0.8 in) per year along
each
of the three rifts which form the "legs" of the triple
junction. 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 at the Dabbahu and Erta
Ale volcanoes. 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, known as the Dabbahu fissure. Related eruptions
have taken place in Teru and Aura woredas
. The rift has recently been recorded by means of three-dimensional
laser mapping.
Erta
Ale is an active shield volcano located in the Afar Region
of northeastern
Ethiopia, within the Danakil Desert. It is the most active
volcano in Ethiopia.
http://www.flickr.com/photos/26162032@N03/2455969983/
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The floor of the Afar Depression is composed of lava, mostly basalt.
One of Earth's five lava lakes, Erta
Ale is found here,
as well as Dabbahu Volcano. It has been proposed that the Afar Depression
is underlain by a mantle plume,
a great upwelling of mantle that melts to yield basalt as it approaches
the surface.
Dallol Depression
The Dallol Depression, also called Danakil Depression, is
a desert with some areas that are more than 100
meters (328 feet) below sea level. This is special because
it is one of the lowest points on earth not covered by
water. There are hot yellow sulfur fields among the sparkling
white salt beds. Heat isn't the only thing people
feel in the Dallol Depression. Alarming earth tremors are
frequently felt. There are also several active volcanoes
. So just how hot is it at the Dallol Depression? Temperatures
can reach as high as 145 degrees Fahrenheit
(63 degrees Celsius) in the sun
http://www.kidzworld.com/article/1203-extreme-climates-3-hottest-place#ixzz1i6pWFlX3
Sulphur
pools and rock formations near Dallol
http://www.youtube.com/watch?v=7HxLbFdu8Jg&feature=related
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Stark
saline cliffs left by an ancient arm of the Red Sea and carved
by its waves,
just above shallow Lake Karum.
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The People.
The Afar-people is a Hamitic people that have lived here for thousand
of years. They numbers about 250.000 (1970)
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Left:
A woman and child of the Danakil.
Right: Braids and ornate costume show her to be the unwed
daughter of a wealthy man.
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Restling
camels park behind those handsome Danakil-girls in a market of the
highlandtown of Batie.
Caucasian features, in some cases blended with Negro, characterize
the Danakils,
a Hamatic people linked by legend to the Biblical sons of Ham, son
of Noah, from whom we all descend.
A
pole in each hand, miners pry loose slabs of solid salt from the
drying bed of Lake Karum.
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Readymade
bricks of salt - and loading salt for transport by camels.
© http://ai.stanford.edu/~latombe/mountain/photo/ethiopia/danakil.htm
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Later they are sliced into manageable bricks, that lure an
endless procession
of salt caravans, Here near the village of Bohale, bound for
the provincial
capital, Makale.. |
Although
Ethiopians who live on the more heavily populated plateau sometimes
come down to the lowlands to mine salt,
most of this work is done by Danakil, who over the centuries have
grown used to the fearful heat.
The salt beds themselves were created over millennims by the evaporation
of sea water, geologists have determined that
this area was once an arm of the Red Sea. No one has ever probed
to the bottom of Lake Karum's salt deposits,
but estimates of their depth run to 5 kilometers or more....They
provide pure white, ready -to-use salt for a large area
of northeastern Africa.
Mobile
home on a sea of ash. Oblivious to a kid browsing inside their house,
nomads rest on a slope of
volcanic debris. Goatskins and straw mats for extra roofing lie
beside the brush igloo.
When water and forage run short, the family will bundle the callapsible
shelter onto a camel and move on.
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Barren
plain sprouts new houses near Tandabo. Each dwelling contains
a kitchen, and many have bath-luxuries previously uunknown.
Government holds demonstrations on cultivating cotton. Houses,
fields
and training may be had for the asking by any landless Ethiopian.
Yet there are few takers among th Danakil, a people unwilling
to
forsake the desert's hard freedom |
Some
Danakil, it is true, have been more or less settled for a very long
time. Their villages stretch along the Awash River,
from Aisaita to Lake Gamarri. Near Aisaita they cultivate cotton,
but elsewhere along the river, cotton gradually gives
way to corn and sesame.
Trailing
evenings shadows, goats trot purposefully past their herder,
bound for a water hole.
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The
People here live in the same easily assembled brushwood huts as
do the nomads, from whom they are indistinguishable
to an outsider. Like nomads, they also own herds of cattle, camels,
sheep and goats. Both the settle and the nomadic
Danakil eat meat only on rare occasions, preferring to conserve
their livestock as precious capital.
On
the move in the time-honored manner, Danakil lead camels
laden with hut poles and all their worldy goods.
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The
part about The People are from National Geographic, February,
1970, Vol.137, No.2, by Victor Eglebert,
who also have taken the above photos, except 'cottonpicker' and
'unwed daughter'. and where otherwise are mentioned.
Women
from the Danakil area.
©
http://ai.stanford.edu/~latombe/mountain/photo/ethiopia/danakil.htm
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Children
are the same, all over the world. Don't you agree?
© pbOOg.cOm / Children
from Ahmed Ela
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