Report on Reventador (Ecuador) — 21 March-27 March 2007
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 21 March-27 March 2007
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2007. Report on Reventador (Ecuador) (Sennert, S, 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.
Geological Summary. Volcán El 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 stratovolcano has 4-km-wide avalanche scarp open to the E formed by edifice collapse. A young, unvegetated, cone rises from the amphitheater floor to a height comparable to the rim. It has been the source of numerous lava flows as well as explosive eruptions visible from Quito, about 90 km ESE. Frequent lahars in this region of heavy rainfall have left extensive deposits on the scarp slope. The largest recorded 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.