Ol Doinyo Lengai, Tanzania

The Toulouse VAAC reported that an ash plume from Ol Doinyo Lengai was observed by visiting scientists on 20 December and rose to an unreported altitude.

Source: Toulouse Volcanic Ash Advisory Center (VAAC) – “Reports provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”