Report on Reventador (Ecuador) — 15 October-21 October 2003
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 15 October-21 October 2003
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2003. Report on Reventador (Ecuador). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 15 October-21 October 2003. Smithsonian Institution and US Geological Survey.
0.077°S, 77.656°W; summit elev. 3562 m
All times are local (unless otherwise noted)
During 13-19 October at Reventador, 77 volcano-tectonic and 17 long-period earthquakes were recorded, averaging eleven and two earthquakes per day, respectively. Lahars were reported on 13, 14, and 19 October. The lahar on 13 October was the largest of the week, lasting ~75 minutes.
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.