Report on Sangay (Ecuador) — 5 January-11 January 2022
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
5 January-11 January 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, 5 January-11 January 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 staff observed Sangay during an overflight on 27 December 2021, focusing on the summit area along with the SE and NE flanks. Two vents were active in the summit area, a central vent and a western vent in a scoria cone. The central vent produced Strombolian explosions and had temperatures as high as 645 degrees Celsius. Lava from this vent fed a flow on the SE flank that was 540 m long; the maximum temperature of the flow was 580 degrees. The W vent ejected blocks and gas emissions, and had temperatures as high as 410 degrees. The third vent, on the NE flank, produced gas emissions and temperatures above 515 degrees. A lava flow from this vent had descended 370 m and was as hot as 450 degrees. The team took gas measurements around the summit with a MultiGAS instrument, collected ash samples, and acquired data and conducted maintenance at the SAGA monitoring station, 6 km SW of the summit.
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 horseshoe-shaped 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 sculpted by heavy rains into steep-walled canyons up to 600 m deep. The earliest report of a historical eruption was in 1628. More or less 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.