The IG reported that although visual observations of Tungurahua were occasionally limited due to cloud cover; gas-and-ash plumes were seen and rose to altitudes of 5.5-7.5 km (18,000-24,600 ft) a.s.l. during 11-17 February. Plumes drifted W, NE, E, and SE. On 11 February, small lahars descended multiple gorges to the NW and S. Incandescence in the crater was seen at night on 11 and 12 February, and roaring was heard on 12 and 16 February. Ashfall was reported in areas to the SW on 12 February and to the N on 14 February. An explosion on 16 February that vibrated windows was followed by ash emissions that generated a plume to an altitude of 8 km (26,200 ft) a.s.l. The plume drifted W.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG) – “Reports provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”