IG reported that during the last week of October the intensity of explosions at Reventador slightly increased; ash plumes, generated from 4-5 explosions per hour, rose to more than 2.5 km above the crater rim and had a higher ash content. Plumes typically drifted W, but also occasionally S and N. Loud “cannon shot” sounds accompanying some explosions were heard in nearby towns. IG volcanologists conducting fieldwork on 23 and 25 October noted strong explosions producing “cannon shots” that vibrated windows in Hostería Reventador, 7.2 km away. On 27 October ash plumes rose as high as 4.9 km. During 30-31 October ashfall was reported in multiple towns in the Napo Province to the S, mainly due to a change in wind direction and not increased activity.

Geological Summary. Volcán El Reventador is the most frequently active of a chain of Ecuadorian volcanoes in the Cordillera Real, well east of the principal volcanic axis. The forested, dominantly andesitic stratovolcano has 4-km-wide avalanche scarp open to the E formed by edifice collapse. A young, unvegetated, cone rises from the amphitheater floor to a height comparable to the rim. It has been the source of numerous lava flows as well as explosive eruptions visible from Quito, about 90 km ESE. Frequent lahars in this region of heavy rainfall have left extensive deposits on the scarp slope. The largest recorded eruption took place in 2002, producing a 17-km-high eruption column, pyroclastic flows that traveled up to 8 km, and lava flows from summit and flank vents.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)