Corbetti Volcano | John Seach



7.18 N, 38.43 E
summit elevation 2320 m

Corbetti Volcano is located on the northern shore of Lake Awasa. It can be seen from the Addis Ababa-Wondo road, where it appears with a broad, low, but prominent profile.

Corbetti volcano is located within the Main Ethiopian Rift. It lies at the northern end of the Lake Awasa basin, a tectonic depression within an uplifted region against the eastern margin of the Rift. This eastern boundary escarpment is sharply defined
in the Lake Awasa basin and to the south, but in the Shashamanne region to the north is only indefinitely preserved.

Corbetti is a composite volcano of obsidian lavas and pumice-ash flows and beds. Its squat shield covers an area of about 65 sq. km. The central part of the volcano lies buried under the most recent obsidian lavas, but the visible surface features permit the identification of seven eruptive centres which have been active at various periods during the history of Corbetti.

I. Main Vent. The highest part of Corbetti is formed by a gently shaped dome rising above the flat, shield-profile of the volcano. This dome represents the site of Main Vent, and the crest of the dome is marked by a subsidence bowl 800 by 300 metres, elongated E-W, and limited both north and south by important sets of fissures.

2. East Vent. East Vent has provided the second of the two recently voluminous obsidian lava centres of Corbetti. These recent obsidian lavas have flowed to a radius of 2 km from East Vent centre, to both the north and east, and as a narrow tongue to the south.

3. Hot Cone. Hot Cone is closely centrally situated in the Corbetti massif, immediately ENE of Main Vent, and is today associated with the most active secondary volcanic phenomena found on the volcano. Hot Cone consists of a 2 km diameter cone upon which a newer 800 m diameter cone has been superimposed.

4. West Vent. West Vent shows evidence of pyroclastic eruptions which were followed by obsidian lavas.

5. North Vent. North Vent has given rise to the second most extensive volcanic eruptions at Corbetti volcano.

6. North-East Vents I and II. These closely related pyroclastic centres are perhaps the oldest preserved features of Corbetti volcano. Their now imperfect and denuded craters average 800 m diameter. Fumarolic activity is present in the deep gullies on the eastern flanks of NE I cone.

7. Other features. The relatively ancient volcanic ash hills, now severely denuded, which lie west of Corbetti, still bear traces of a crater 4 km directly west of North Vent.

The volcanic nature of the mountain was first recognised in 1959 during an aerial survey, when steam-clouds were observed emerging from deep gullies on the flanks of a subsidiary cone. The severely broken nature of the obsidian lava and the dense growth of thorn-scrub made precise determination of the summit impossible when a field crew tried to climb the volcano in 1964.

2016 Earthquake
On 30th January a magnitude 4.5 Earthquake hit under Corbetti volcano. The epicentre was 11 km northwest of the town Awassa, on the NW side of lake Awassa.

Further reading
Lavayssière, Aude, et al. "Local seismicity near the actively deforming Corbetti volcano in the Main Ethiopian Rift." Journal of Volcanology and Geothermal Research 381 (2019): 227-237.

Rapprich, Vladislav, et al. "Wendo Koshe Pumice: The latest Holocene silicic explosive eruption product of the Corbetti volcanic system (southern Ethiopia)." Journal of Volcanology and Geothermal Research 310 (2016): 159-171.

Di Paola, G.M., 1971. Geology of the Corbetti Caldera area (Main Ethiopian Rift Valley). Bulletin Volcanologique35(2), pp.497-506.

Corbetti Volcano Eruptions

Fumarolic activity is present at the volcano.
Eruption a few thousand years ago.