On 16 May, IG reported that a steam plume from Reventador rose to an altitude of 3.6 km (11,900 ft) a.s.l. and drifted to the NW. The plume was visible on satellite imagery. On 18 May, strong rains resulted in a lahar that lasted approximately 40 minutes. A lahar was also noted on 22 May. Visual observations were hindered during most of the reporting period due to inclement weather.

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)