Report on Sangay (Ecuador) — 21 September-27 September 2022
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
21 September-27 September 2022
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2022. Report on Sangay (Ecuador). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 21 September-27 September 2022. Smithsonian Institution and US Geological Survey.
2.005°S, 78.341°W; summit elev. 5286 m
All times are local (unless otherwise noted)
IG reported a high level of activity at Sangay during 20-27 September. Daily seismic counts ranges were 702-1,152 explosions, 12-105 long-period events, and 9-95 tremor events indicating emissions. Daily ash-and-gas plumes were identified in IG webcam images and visible in satellite images according to the Washington VAAC. Plumes generally rose as high as 2 km above the volcano but during 25-27 September they rose as high as 3 km. The plumes drifted mostly W and NW, but some drifted SW, N, and NE. Daily thermal anomalies were identified in satellite images. Ashfall was reported in the Chauzán sector, Chimborazo province, during 22-23 September.
Geological Summary. The isolated Sangay volcano, located east of the Andean crest, is the southernmost of Ecuador's volcanoes and its most active. The steep-sided, glacier-covered, dominantly andesitic volcano grew within the open calderas of two previous edifices which were destroyed by collapse to the east, producing large debris avalanches that reached the Amazonian lowlands. The modern edifice dates back to at least 14,000 years ago. It towers above the tropical jungle on the east side; on the other sides flat plains of ash have been eroded by heavy rains into steep-walled canyons up to 600 m deep. The earliest report of an eruption was in 1628. Almost continuous eruptions were reported from 1728 until 1916, and again from 1934 to the present. The almost constant activity has caused frequent changes to the morphology of the summit crater complex.