IG reported that scientists aboard an overflight of Reventador on 23 November observed steam-and-gas emissions with slight amounts of ash rising 500 m above the lava dome and drifting WSW. The lava dome had intense fumarolic activity and there was a new crater at the summit of the dome, which was filled with ash and large blocks. A thermal camera measured temperatures in the dome of about 300 degrees Celsius. Lava flows continued to be active on the dome flanks, and elongated block-and-ash deposits were also visible on the flanks.

According to the Washington VAAC, the IG reported that on 24 November an ash plume from Reventador rose to an altitude of 4.6 km (15,000 ft) a.s.l. Ash was not detected in satellite imagery due to cloud cover, but a thermal anomaly was detected.

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)