Suswa Volcano | John Seach


(Ol Doinyo Nyukie)

1.175 S, 36.35 E
summit elevation 2356 m
Shield volcano

Suswa volcano contains the southern-most caldera in the Kenyan (Gregory) Rift Valley. It contains a 12 x 8 km caldera with the rim at an altitude of 1890 m. Suswa is the closest active volcano to Nairobi, the capital of Kenya (50 km). Future eruptions of the volcano may have a significant effect on the city.

Suswa volcano photos by John Seach

suswa volcano
Suswa volcano - John Seach

Suswa caves
Mt Suswa caves, Kenya

suswa caves, kenya
Suswa caves

suswa caves
Lava tube at Suswa volcano - John Seach

Suswa volcano
Mt Suswa caves

Mt Suswa, Kenya
Mt Suswa, Kenya

Mt Suswa volcano, Kenya
Suswa volcano, Kenya

Suswa volcano contains an unusual island-block and caldera structure which is also seen at Poseidonius and Gassendi craters on the moon.

Eruptions at the volcano are divided into three periods.
1) Initial eruptions formed a shield volcano with an oval outline and covering 130 sq miles. Lava flows were viscous and sluggish. The main eruptive phase was followed by eruptions from several small cones distant from the main volcano.

2) After a period of quiet of unknown duration (probably several hundred thousand years) there was a second eruptive phase at the volcano. The eruption centre moved SW along a fracture line and formed a second cone called Ol Doinyo Nyukie. This cone had an asymmetrical shape and a ventral vent which visible as a partly preserved pit crater.

3) The most recent sequence of eruptions at the volcano was the least significant in size.

Recent Eruptions of Suswa
The most recent lavas at Suswa have only a sparse cover of vegetation, therefore have erupted in the past few centuries. Fumarolic activity at Suswa is more widespread than other caldera volcanoes in Kenya. A 15 km long lava flow extends SE, then SSE towards the base of the rift valley scarp.

Further reading
Skilling, I.P., 1993. Incremental caldera collapse of Suswa volcano, Gregory rift valley, Kenya. Journal of the Geological Society150(5), pp.885-896.

Johnshon, R.W., 1969. Volcanic geology of Mount Suswa, Kenya. Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences265(1164), pp.383-412.

Nash, W.P., Carmichael, I.S.E. and Johnson, R.W., 1969. The mineralogy and petrology of Mount Suswa, Kenya. Journal of Petrology10(3), pp.409-439.

McCall, G.J.H. and Bristow, C.M., 1965. An introductory account of Suswa volcano, Kenya. Bulletin Volcanologique28(1), pp.333-367.

Suswa Volcano Eruptions

Current activity at the volcano consists of fumarolic activity along fracture lines.