Report on Reventador (Ecuador) — 30 July-5 August 2008
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
30 July-5 August 2008
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2008. Report on Reventador (Ecuador). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 30 July-5 August 2008. Smithsonian Institution and US Geological Survey.
0.077°S, 77.656°W; summit elev. 3562 m
All times are local (unless otherwise noted)
The IG reported that seismicity from Reventador decreased during 30-31 July. On 31 July, steam-and-gas plumes with a low ash content were detected on satellite imagery and drifted W and SW. On 1 August, steam-and-gas plumes were emitted and a lava flow in the caldera was active. Diffuse ash emissions were noted on 2 August. On 3 August, IG scientists observed the lava flow in the caldera and estimated that it advanced at a rate of 100 m per day. They also heard sporadic roaring noises. Gas-and-steam plumes were noted on 5 August.
Geological Summary. 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.