During an overflight of Reventador on 29 January scientists observed an explosion and a steam-and-ash plume that rose 1.5 km above the lava dome. Since November the dome had significantly grown to at least 100 m higher than the E rim, and about 20 lava flows had traveled down the N, SE, and S flanks.

During 29 January-5 February seismicity remained high. Cloud cover often prevented observations although emissions were observed; steam-and-ash plumes rose 2-4 km and drifted W and NW on most days. Crater incandescence was observed at night during 29-30 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)