IG reported that a high level of activity continued to be recorded at Reventador during 1-8 June; adverse weather conditions sometimes prevented visual confirmation. Seismicity was characterized by 3-23 daily explosions, volcano-tectonic and harmonic tremor events, long-period earthquakes, and signals indicating emissions. Gas, steam, and ash plumes, often observed multiple times a day with the webcam or reported by the Washington VAAC, rose higher than 1 km above the summit crater and drifted mainly W, NW, and NE. Crater incandescence and incandescent blocks rolling as far as 500 m down the S flank were occasionally observed at night. Lava flows on the N, NE, SE, and S flanks were active. The report also noted that a bulging area on the N flank first detected on 13 May had persisted.

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)