Report on Reventador (Ecuador) — 1 November-7 November 2017
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
1 November-7 November 2017
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2017. Report on Reventador (Ecuador). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 1 November-7 November 2017. 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 the last week of October the intensity of explosions at Reventador slightly increased; ash plumes, generated from 4-5 explosions per hour, rose to more than 2.5 km above the crater rim and had a higher ash content. Plumes typically drifted W, but also occasionally S and N. Loud “cannon shot” sounds accompanying some explosions were heard in nearby towns. IG volcanologists conducting fieldwork on 23 and 25 October noted strong explosions producing “cannon shots” that vibrated windows in Hostería Reventador, 7.2 km away. On 27 October ash plumes rose as high as 4.9 km. During 30-31 October ashfall was reported in multiple towns in the Napo Province to the S, mainly due to a change in wind direction and not increased activity.
Geological Summary. 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.