According to Frederick Belton’s Ol Doinyo Lengai website, a visitor reported a large plume accompanied by a “bang” during 26-27 February. The Toulouse VAAC reported that a pilot observed an ash plume that rose to an altitude of 10.7 km (35,000 ft) a.s.l. on 27 February. Another possible ash plume rose to the same altitude on 28 February and drifted SW. Based on a SIGMET, pilot reports, and observations of satellite imagery, the VAAC reported that eruption plumes possibly containing ash rose to altitudes of 10.7-13.7 km (35,000-45,000 ft) a.s.l. during 29 February and 3-4 March.
Sources: Frederick Belton’s Ol Doinyo Lengai website, Toulouse Volcanic Ash Advisory Center (VAAC) – “Report provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”