IG reported that during 8-12 July seismic data from Reventador’s network indicated a high level of seismic activity, including explosions, harmonic tremor, and long-period earthquakes; there was no available seismic data during 13-14 July. Gas, steam, and ash emissions observed daily with the webcam or reported by the Washington VAAC rose as high as 1 km above the summit crater and drifted NW, W, and E. Cloudy weather sometimes prevented views of the volcano. Incandescent blocks rolled as far as 600 m down mainly the S and SE flanks during 8-9 and 12-14 July. Crater incandescence was visible almost nightly.

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)