On 28 March, observers reported roaring noises and an ash column from Reventador that rose to an altitude of 5.6 km (18,400 ft) a.s.l. and drifted W. A small lava flow traveled 200 m down the S flank. Incandescent material and ash emissions were observed during 29-31 March. On 1 April, ash plumes rose to an altitude of 7.6 km (24,900 ft) a.s.l. and incandescent rocks were ejected about 50 m above the crater. Incandescent material was again seen at the summit on 2 April. The Washington VAAC reported that a strong hotspot was present on satellite imagery during 1-3 April. Based on pilot reports, IG reported that a steam-and-gas plume with little ash content rose to an altitude of 6.1 km (20,000 ft) a.s.l. and drifted W 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.

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