More detailed information about the recent activity at Lengai has emerged: there was probably no explosive eruption as reported earlier, but one or two very large effusive paroxysms: the first eruption occurred on 29 March, the second probably on 3 April. The eruptions produced large-volume natrocarbonatite lava flows that overflowed the crater to the West near the climbing route, travelled for more than 1 km length through a small canyon before stopping less than two km from a Maassai village at the base of the mountain.
Buring vegetation ignited by the lava might have produced smoke that had been mistaken for ash. No evacuations have taken place and no one has left the area, different from early news reports.
The activity at Lengai volcano, that started around 30 March is still enigmatic. According to information compiled by our colleague Fred Belton, a lava flow and lava fountains were emitted on the 30th, but there were no ash emissions. A steam plume was visible that may have been mistakenly described as ash in news reports. According to an observer in Tanzania, on 4 April a very large lava flow was visible on the volcano's W flank. The lava flow was over 1 km long and had traveled down the flank of the volcano and into a gorge. There were no signs that the flow was still hot. Photographs revealed that another lava flow may have traveled W of the volcano on 3 or 4 April. On 7or 8 April, active lava was contained within a new lava lake (?) at the summit. There are contradictory reports about evacuations evacuations from villages near the volcano.