IG reported that although visual observations were occasionally limited due to cloud cover, ash-and-steam and ash plumes from Tungurahua were seen and rose to altitudes of 6-8 km (19,700-26,200 ft) a.s.l. during 25 December-1 January. Plumes drifted predominantly W and ashfall was reported in areas downwind and to the SW and N. Roaring noises and “cannon shots” were heard almost daily and windows and floors vibrated on 26, 27, and 30 December. During 26-27 December, incandescent blocks rolled down the flanks as far as 500 m. On 29 December, incandescent material observed at the summit was associated with explosive events. Incandescent blocks rolled 700 m down the NW flank on 29 December and 1,200 m down the flanks on 30 December. Incandescence at the summit was noted again on 31 December during the night.
Sources: Instituto Geofísico-Escuela Politécnica Nacional , Associated Press – “Reports provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”