According to the Washington VAAC, a pilot reported an ash plume from Nevado del Huila on 17 April. An ash plume that was evident on satellite imagery at 0415 rose to an approximate altitude of 11.3 km (37,000 ft) a.s.l. and drifted E. An additional plume drifted SW. Later that day, INGEOMINAS reported increased seismicity. At 0257 on 18 April, INGEOMINAS reported an eruptive event. Based on a news article, an eruption triggered landslides and swelled rivers. About 5,000 people evacuated from areas to the S.

Geological Summary. Nevado del Huila, the highest peak in the Colombian Andes, is an elongated N-S-trending volcanic chain mantled by a glacier icecap. The andesitic-dacitic volcano was constructed within a 10-km-wide caldera. Volcanism at Nevado del Huila has produced six volcanic cones whose ages in general migrated from south to north. The high point of the complex is Pico Central. Two glacier-free lava domes lie at the southern end of the volcanic complex. The first historical activity was an explosive eruption in the mid-16th century. Long-term, persistent steam columns had risen from Pico Central prior to the next eruption in 2007, when explosive activity was accompanied by damaging mudflows.

Sources: Washington Volcanic Ash Advisory Center (VAAC), Mail and Guardian Online, Servicio Geológico Colombiano (SGC)