The IG reported that during 18-19 June, ash-and-steam plumes from Tungurahua rose to altitudes of 6-8 km (19,700-26,200 ft) a.s.l. and drifted W, NW, and N. On 18 June, a small explosion was detected by the seismic network, and sounds of blocks rolling down the flanks, roaring noises, and “cannon shots” were reported. On 19 June, ashfall was reported in areas NW and W; in Cotaló, about 8 km NW, ash deposits measured about 2 mm thick. Incandescent material and blocks were ejected 500 m above the summit. Blocks rolled about 1 km down the flanks and roaring noises were reported. On 20 June, clouds inhibited visual observations of the summit. Lahars descended NW, W, and S drainages. A mudflow that traveled SW towards the Puela river carried blocks up to 80 cm in diameter.
On 21 June, two periods of increased seismicity were accompanied by strong ash emissions. The resultant ash plumes rose to altitudes of 8-11 km (26,200-36,100 ft) a.s.l. and drifted W. Intense ashfall was reported in areas within 8 km W and SW of the crater. On 22 June, lahars descended several drainages on the W and S flanks. Steam plumes with small ash content rose to an altitude of 6 km (19,700 ft) a.s.l. and drifted W. Roaring noises vibrated windows in areas to the W. During 23-24 June, seismicity decreased and visual observations were inhibited by clouds.
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.”