Based on visual observations during clear weather, INGEOMINAS reported that steam-and-gas plumes from Galeras rose to a maximum altitude of 5.3 km (17,400 ft) a.s.l. during 21-23 November and 3 December. The plumes occasionally contained small volumes of ash and were associated with seismic tremor. Gas and ash plumes that rose to an altitude of 4.4 km (14,400 ft) a.s.l. and drifted NW were observed during an overflight on 27 November. Thermal images indicated an increase in temperatures since a 2 October overflight at the point sources of emissions. The Alert Level remained at 3 (changes in the behavior of volcanic activity have been noted) on a scale of 4-1.
Sources: Instituto Colombiano de Geología y Minería – “Report provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”