Report on Reventador (Ecuador) — 3 August-9 August 2011
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
3 August-9 August 2011
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2011. Report on Reventador (Ecuador). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 3 August-9 August 2011. Smithsonian Institution and US Geological Survey.
0.077°S, 77.656°W; summit elev. 3562 m
All times are local (unless otherwise noted)
The IG reported that scientists conducting an overflight of Reventador on 14 July noted that the lava dome at the top of the 2008 cone continued to grow, filling the crater. The dome had reached the same height as the highest part of the crater rim, formed during 2002. Intense fumarolic activity produced continuous plumes. The dome was thought to have formed during 2011, growing at a rapid rate and producing high temperatures. IG also noted that seismicity had increased starting in May but was more pronounced during the previous few weeks. During 3-9 August cloud cover prevented observations of the lava dome, but the seismic network detected long-period and explosion-type earthquakes.
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.