IG reported moderate volcanic activity including explosions, long period earthquakes, harmonic tremor, and tremor at Reventador during 30 July-5 August. On most days IG reported inclement weather with intermittent views of steam-and-ash plumes that rose above the crater and drifted W. On 2 August IG noted a steam-and-ash plume rose 2 km above the crater accompanied by seven emission tremor events. On 31 July Washington VAAC reported on-going ash emissions and detected hotspots at the crater.

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.

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Washington Volcanic Ash Advisory Center (VAAC)