Report on Reventador (Ecuador) — 15 May-21 May 2019
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 15 May-21 May 2019
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2019. Report on Reventador (Ecuador). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 15 May-21 May 2019. 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 during 14-21 May seismic data from Reventador’s network indicated a high level of seismic activity, including explosions, long-period earthquakes, harmonic tremor, and signals indicating emissions. Weather conditions often prevented views of the summit area, although when clear (during 17-18 and 20-21 May) several ash plumes were visible rising as high as 1 km above the crater rim and drifting W and NW. Crater incandescence was visible on some mornings and evenings. On 19 May a 500-m-long pyroclastic flow deposit on the N flank was visible. Blocks were observed rolling 800 m down the flanks on 21 May.
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.