The IG reported that activity from Tungurahua on 15 December was characterized by increased seismicity, ash emissions, and the ejection of incandescent blocks. Ash plumes rose to an altitude of 6 km (19,700 ft) a.s.l. and drifted NE. Ashfall was reported 6 km NNE in Runtún. Observers at the Tungurahua Observatory (OVT) in Guadalupe, 11 km N, saw incandescent blocks ejected from the summit fall onto the W flank. Later that night, ash plumes rose to altitudes of 7 km (23,000 ft) a.s.l. and incandescence was seen at the summit. Emissions with variable ash content were seen on 16 December.
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.”