Report on Reventador (Ecuador) — 20 January-26 January 2021
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 20 January-26 January 2021
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2021. Report on Reventador (Ecuador). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 20 January-26 January 2021. Smithsonian Institution and US Geological Survey.
0.077°S, 77.656°W; summit elev. 3562 m
All times are local (unless otherwise noted)
IG reported that a high level of activity continued to be recorded at Reventador during 19-26 January; adverse weather conditions sometimes prevented visual conformation. Seismicity was characterized by 42-106 daily explosions, volcano-tectonic and harmonic tremor events, and long-period earthquakes as well as signals indicating emissions. Gas, steam, and ash plumes, often observed multiple times a day with the webcam or reported by the Washington VAAC, rose as high as 1 km above the summit crater and drifted mainly NW, W, and SW. Crater incandescence and incandescent blocks rolling 600-800 m down the NE and S flanks were observed on some nights. A new lava flow was active on the N flank.
Geologic Background. 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 Volcán El Reventador stratovolcano rises to 3562 m above the jungles of the western Amazon basin. A 4-km-wide caldera widely breached to the east was formed by edifice collapse and is partially filled by a young, unvegetated stratovolcano that rises about 1300 m above the caldera floor to a height comparable to the caldera rim. It has been the source of numerous lava flows as well as explosive eruptions that were visible from Quito in historical time. Frequent lahars in this region of heavy rainfall have constructed a debris plain on the eastern floor of the caldera. The largest historical 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.