IG reported that during 10-16 July seismic activity at Reventador was high; weather conditions mostly prevented visual observations of the crater. During partially clear views on 13 July, observers noted a new lava flow on the S flank. At 1500 on 15 July continuous tremor was detected, which intensified at 2000, and then decreased at midnight. Intense Strombolian activity during this time was characterized by variable-magnitude explosions and roaring. Explosions generated blocks that rolled down the flanks. Incandescence from the lava flow on the S flank was observed.

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)