Report on Reventador (Ecuador) — 21 November-27 November 2012
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 21 November-27 November 2012
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2012. Report on Reventador (Ecuador). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 21 November-27 November 2012. 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 scientists aboard an overflight of Reventador on 23 November observed steam-and-gas emissions with slight amounts of ash rising 500 m above the lava dome and drifting WSW. The lava dome had intense fumarolic activity and there was a new crater at the summit of the dome, which was filled with ash and large blocks. A thermal camera measured temperatures in the dome of about 300 degrees Celsius. Lava flows continued to be active on the dome flanks, and elongated block-and-ash deposits were also visible on the flanks.
According to the Washington VAAC, the IG reported that on 24 November an ash plume from Reventador rose to an altitude of 4.6 km (15,000 ft) a.s.l. Ash was not detected in satellite imagery due to cloud cover, but a thermal anomaly was detected.
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.