Ardoukoba Volcano | John Seach

john

Djibouti

11.58 N, 42.47 E
summit elevation 298 m
fissure vents

Ardoukoba Volcano is located on the coast 100 km from Djibouti city. Ardoukoba Volcano erupted in 1978 for one week after an earthquake created a 1.8 m fissure. This was the first eruption of Ardoukoba Volcano in 3000 years.

Two lava flows were erupted, 1 km to the SE, and 0.5 km to the NW. Ash emissions reached 300 m altitude, and a crater 30 wide and 100 m high was formed.

The Ardoukoba rift is 17 km wide and 800 m deep. The most recent flows are
concentrated within the Inner Floor. Exposed rocks of the Ardoukoba Rift trend from basalts to ferrobasalts (~15% total Fe), with andesine basalts the most abundant group recognized.

The maximum thickness of recent flows in the Ardoukoba rift is 10 m, which gives a minimum eruption rate of 3000 cubic m/km/year over a 3000 year period.

The Inner Floor is the area of thinnest and weakest lithosphere. In the Ardoukoba Rift it is the site of active extension with fissures and faulting.

1978 Eruption
An eruption began on 7th November, after a period of 24 hours where 800 earthquakes (< magnitude 3.3) were recorded. The eruption occurred at a 500 m long fissure about 3 km SE of Lake Assal. Three spatter cones formed over the fissure. The eruption shifted 0.5 km SE and formed a cone. Two lava flows occurred and 25 fissures opened parallel to the main rift zone. The eruptions ended by 16th November.

Further reading
Vigier, N., Bourdon, B., Joron, J.L. and Allegre, C.J., 1999. U-decay series and trace element systematics in the 1978 eruption of Ardoukoba, Asal rift: timescale of magma crystallization. Earth and Planetary Science Letters174(1-2), pp.81-98.

Gerlach, T.M., 1989. Degassing of carbon dioxide from basaltic magma at spreading centers: I. Afar transitional basalts. Journal of Volcanology and Geothermal Research39(2-3), pp.211-219.

Ardoukoba Volcano Eruptions

1978