INGEOMINAS reported an explosive eruption from Galeras that began at 0705 on 20 February; the Alert Level was raised from II (Orange; “probable eruption in term of days or weeks”) to I (Red; “imminent eruption or in progress”), on a scale of 4-1. The eruption was accompanied by shock waves detected in several local communities and produced sounds heard in Popayán (about 160 km NNE). Observers from areas on the E flank reported two explosions, incandescent blocks ejected above the summit, ash emissions, and sulfur gas odor. An ash plume rose to an altitude of 12.5 km (41,000 ft) a.s.l. and drifted E, W, and N. Ashfall was reported in areas to the W. Gas plumes with a low ash content continued, especially in the afternoon, and rose 700 m above the summit. On 21 February, the Alert Level was lowered to back to II. During 22-24 February, occasional steam plumes rose 500 m above the summit and drifted NNW.
Source: Instituto Colombiano de Geología y Minería (INGEOMINAS) – “Report provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”