Gedamsa Volcano | John Seach



8.35 N, 39.18 E
summit elevation 1984 m

The volcano is located east of Lake Koka. It contains a 9 x 7 km wide caldera.

The rim of the caldera is well preserved with vertical inside walls 100-200 m high. Only a small section of the NW rim has been eroded. The rocks which form the rim of the caldera are mostly rhyolitic lavas, even with the presence of pumice and ignimbrites.

The interior of the caldera shows several signs of post-caldera activity. Some small domes are visible consisting of pumice falls with subordinate rhyolitic lavas. The most important feature is an irregular chain of hills rising for about 200-250 m from the floor of the caldera. It is made up of alternations of rhyolitic lavas and pumice deposits. This chain is locally named Ittisa and, on its eastern part, there is a large crater with a diameter of about 1 km and a depth of about 100 m.

Weak traces of fumarolic activity are visible at the base of the western rim of the caldera and on a small pumice dome on the West.

Further reading
Williams, F.M., 2016. The Rift Valley Southwards: Volcanoes, and Lakes Ancient and Modern. In Understanding Ethiopia (pp. 179-196). Springer, Cham.

Gedamsa Volcano Eruptions

No recent eruptions.