Report on Reventador (Ecuador) — 6 November-12 November 2002
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 6 November-12 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, 6 November-12 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)
Volcanic activity decreased following the large eruption at Reventador on 3 November, but small-to-moderate eruptions continued during 5-12 November. IG reported that on the 5th, explosions produced SW-drifting ash-and-gas clouds to heights between 3 and 6 km. Ash fell in the town of Chaco. On the 7th an eruption sent an ash-and-gas cloud to 7 km that drifted W. Rain during the evening of the 9th caused mudflows to travel down the volcano's flanks, closing the Chaco-Reventador highway. According to the Washington VAAC, the maximum height reached by ash clouds during the report period was ~10 km a.s.l. On 10 November the Quito airport was reopened, after being closed for a week. Ash from previous eruptions descended on Quito on 11 November, causing officials to close schools and warn residents to protect themselves from inhaling ash.
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.