The IG reported that the number of earthquakes per day from Reventador increased during July and were the greatest on 24 and 25 July. At 1500 on 27 July, continuous seismic tremor was registered and was followed by observations of incandescence around the crater. Thermal anomalies were also identified on satellite imagery. At 1900 explosions produced ash plumes and ejected incandescent material that fell onto and rolled down the flanks. On 28 July, ash plumes drifted NW and W. Ashfall was reported in Olmedo, about 50 km NW. Later that day, ash plumes rose to altitudes of 4-6 km (13,100-19,700 ft) a.s.l. and drifted NW. On 29 July, steam plumes rose from the crater and drifted NW. A sulfur smell was reported at areas around the volcano. A lava flow traveled S.
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.”