Report on Sangay (Ecuador) — 16 August-22 August 2017
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 16 August-22 August 2017
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2017. Report on Sangay (Ecuador) (Sennert, S, ed.). Weekly Volcanic Activity Report, 16 August-22 August 2017. Smithsonian Institution and US Geological Survey.
2.005°S, 78.341°W; summit elev. 5286 m
All times are local (unless otherwise noted)
Based on information from IG, the Guayaquil MWO, and satellite data the Washington VAAC reported continuing ash emissions at Sangay. On 16 August an ash plume drifted W. On 17 August an ash plume rose to an altitude of 8.2 km (27,000 ft) a.s.l. and drifted NW, and was followed by several more ash puffs. During 19-20 August ash plumes rose to 5.8 km (19,000 ft) a.s.l. and drifted SW and W. A thermal anomaly was identified in satellite images on 20 August.
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.