The Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN) reported that eruptive activity continued at Reventador during 22-28 January. Seismicity was not reported on 22-23 January and only partly recorded on the morning of 24 January, with 22 explosions, due to data transmission issues with the seismic monitoring equipment. From the afternoon of 24 January to the morning of 28 January, seismicity included 63-79 daily explosions, long-period earthquakes, harmonic tremor, and tremor associated with emissions. Weather conditions occasionally obscured views of summit activity; however, when the weather permitted, ash-and-gas plumes were observed in webcam and/or satellite images rising 300-1,300 m above the crater and drifting W, WNW, and NW. The Washington VAAC also issued alerts for ash and gas emissions. The surveillance camera network recorded multiple instances of incandescent material descending as far as 800 m below the crater rim overnight 24-27 January. Secretaría de Gestión de Riesgos maintained the Alert Level at Orange (the second highest level on a four-color scale).

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)