Report on Cotopaxi (Ecuador) — 1 March-7 March 2023
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
1 March-7 March 2023
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2023. Report on Cotopaxi (Ecuador). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 1 March-7 March 2023. Smithsonian Institution and US Geological Survey.
0.677°S, 78.436°W; summit elev. 5911 m
All times are local (unless otherwise noted)
IG reported that the eruption at Cotopaxi continued during 28 February-7 March. Several daily ash, gas, and steam plumes rose as high as 1.5 km above the summit during 28 February-2 March and drifted W and SW. Minor ashfall was reported in Mulaló parish (Colcas-Ticatilín) of the Latacunga canton during the afternoon of 28 February. Steam-and-gas emissions were visible rising as high as 700 m and drifting SW and W during 3-7 March. Minor ashfall was reported in Mulaló parish on 5 March. Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE) maintained the Alert Level at Yellow (the second lowest level on a four-color scale).
Geological Summary. The symmetrical, glacier-covered, Cotopaxi stratovolcano is Ecuador's most well-known volcano and one of its most active. The steep-sided cone is capped by nested summit craters, the largest of which is about 550 x 800 m in diameter. Deep valleys scoured by lahars radiate from the summit of the andesitic volcano, and large andesitic lava flows extend to its base. The modern edifice has been constructed since a major collapse sometime prior to about 5,000 years ago. Pyroclastic flows (often confused in historical accounts with lava flows) have accompanied many explosive eruptions, and lahars have frequently devastated adjacent valleys. Strong eruptions took place in 1744, 1768, and 1877. Pyroclastic flows descended all sides of the volcano in 1877, and lahars traveled more than 100 km into the Pacific Ocean and western Amazon basin. Smaller eruptions have been frequent since that time.
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE)