During 28 March-4 April IG reported a high level of seismic activity including explosions, long-period earthquakes, harmonic tremor, and signals indicating emissions at Reventador. Although cloud cover often prevented visual observations, activity was noted almost daily. During 28 March-3 April steam, gas, and ash plumes rose as high as 1.3 km above the crater rim and drifted SW and NE. Incandescence from the crater was sometimes visible during the night. Incandescent blocks rolled 1 km down the flanks on 1 April, and 1.6 km down the SW flank on 3 April. A small lava flow was observed traveling 1.6 km down the SW flank on 3 April.

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)