IG reported that in the morning of 22 January tremor at Reventador increased significantly and signals indicating rockfalls were detected. Explosions were heard during the afternoon and evening that same day. After an explosion in the crater a gas-and-steam plume was observed rising 1.5 km above the crater. Lava flows traveled down the SW and N flanks. The lava dome had grown at least 100 m above the crater rim.

During 23-29 January seismicity remained high. Cloud cover mostly prevented visual observations; during 22-23 January lava flow were visible at night, and on 24 January a steam-and-ash plume rose 2 km. Gas plumes rose as high as 1 km and drifted NW and W on 29 January.

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)