While in the field on 15 January, IG technicians observed several explosions at Reventador that generated ash plumes which rose 1.5-2 km above the crater. A pyroclastic flow traveled 500 m down the N flank. Pyroclastic flow deposits from the previous three weeks were also noted. Activity during 19-25 January remained high. At 2200 on 19 January a major explosion, heard in El Reventador village, ejected incandescent material onto the SW flank. Gas, steam, and ash emissions rose 0.8-2 km above the crater on most days. During 21-22 January incandescent material traveled 1.2 km down the W flank.

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)