Report on Reventador (Ecuador) — 21 March-27 March 2007
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 21 March-27 March 2007
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2007. Report on Reventador (Ecuador). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 21 March-27 March 2007. 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 during early March, the number of tectonic earthquakes from Reventador increased. Steam-and-ash plumes were sporadically visible and rose to altitudes of 4 km (13,000 ft) a.s.l. occasionally during 8-22 March. On 21 March, noises were reported. The next day, seismic signals changed and indicated possible emissions. On 24 March, local people saw ash plumes and incandescent material near the crater and heard roaring noises. An explosion produced a plume that rose to an altitude of 6.6 km (21,700 ft) a.s.l. and drifted W. Based on reports from IG, the Washington VAAC reported an ash plume to altitudes of 3.7-7 km (12,000-23,000 ft) a.s.l. that drifted NE and WNW during 26-27 March. A thermal anomaly was present on satellite imagery during 24-27 March.
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.