Report on Reventador (Ecuador) — 13 November-19 November 2002
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 13 November-19 November 2002
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2002. Report on Reventador (Ecuador). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 13 November-19 November 2002. Smithsonian Institution and US Geological Survey.
0.077°S, 77.656°W; summit elev. 3562 m
All times are local (unless otherwise noted)
During 12-16 November, seismic and volcanic activity continued at Reventador. Constant tremor, and hybrid and volcanotectonic earthquakes were recorded. On 12 November a column of steam and ash was seen rising 6-7 km above the volcano and drifting to the W. There was only a moderate amount of ash in the cloud, therefore there was not much ashfall. Mudflows traveled down Reventador's flanks and during several evenings incandescence was visible on the NE flank. During a flight over the volcano on the 18th, a lava flow was seen on the crater's S wall advancing slowly. Also, pyroclastic-flow deposits were seen that IG warned may be remobilized during heavy rain, becoming dangerous mud flows.
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.