IG reported that a small pyroclastic flow traveled a few meters below Reventador’s crater on 29 April. Cloud cover occasionally prevented visual observations during 30 April-6 May. An ash plume rose 3-4 km and drifted W on 1 May, and a steam plume with some ash rose less than 1 km the next day. People in Camp San Rafael (8 km ESE) reported that an explosion at 2040 on 4 May ejected a large amount of incandescent material onto the flanks, and generated an ash plume that rose 4-5 km above the crater and drifted NW. Explosions on 5 May produced ash plumes that rose 4 km. At 0925 an explosion vibrated windows in the camp. On 6 May explosions again rattled windows in the camp and a gas plume was observed rising 1 km and drifted W.

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)