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Borale Ale Volcano | John Seach
Erta Ale Range, Ethiopia
13.725 N, 40.60 E
summit elevation 668 m
Stratovolcano
The volcano is located in the centre of Erta Ale Range.
It is volumetrically most important silicic volcano of the Erta Ale range. It is built up by accumulation of viscous lava flows, mainly blocky lava, around the central eruption point which is occupied by a crater of 300 m internal diameter where Fumarolic activity was observed in the winters of 1968 and 1969.
The silicic flows reach a lateral extension of 5 km and the average slope is 25 degrees.
Borale Ale is one of the most complex areas of the Erta Ale range. Two main structures of different ages are superimposed here, which are rejuvenated by recent tectonics and volcanism.
The oldest lavas are found on the eastern side, as in the Dalaffilla area, and consist of submarine flows locally covered by remnants of quaternary reef deposits.
Lava fields building the base of the Borale Ale volcano have been erupted through 3 different types of fissures.
1) A system of central fissures was responsible for the outpouring of the oldest lavas and for the building up of the main part of the volcano.
2)
Later activity at these fissures produced the median bulge-shaped shield volcano.
3) Large pahoehoe flows cover the whole summit area.
The volcano summit is affected by curvilinear faults, frequently having a considerable down-throw (100 m), and forming a small summit graben. As in Dalaffilla volcano, the faults are concave towards the centre, and elongated in the Eritrean direction.
The summit graben is partly filled by a recent small and viscous lava flow and a small endogenous dome of lava altered by fumarolic activity.
The lava fields at the base of the Borale Ale area do not differ in their petrological features from those of the Alu-Dala Filla. It is, in fact, difficult to distinguish between the flows coming from the different volcanoes, the same emitting fissure extending sometimes from one volcano to the other.
Further reading
Barberi, F. and Varet, J., 1970. The Erta Ale volcanic range (Danakil depression, northern afar, Ethiopia). Bulletin Volcanologique, 34(4), pp.848-917.
Watanabe, H. and Matsuo, K., 2003. Rock type classification by multi-band TIR of ASTER. Geosciences Journal, 7(4), pp.347-358.
Borale Ale Volcano Eruptions
No recent eruptions.