SERNAGEOMIN reported that continuous emissions of gas-and-ash plumes from Chaitén were observed on 13 August, after three days of bad weather prevented visual observations. Plumes rose to an altitude of 2 km (6,600 ft) a.s.l., but later that day rose to greater altitudes of 6-7 km (19,700-23,000 ft) a.s.l. The increased activity did not correspond to any significant variation in seismicity. Plumes were emitted from two areas on the E and S flanks and were different colors; the area on the E flank produced steam plumes with minor ash content and the area on the S flank emitted darker ash plumes. The plumes drifted SW and caused ashfall in Chaitén town for several hours. The ash accumulation was 1.5 cm thick.
Based on web camera views, SIGMET reports, analysis of satellite imagery, and information from the Puerto Montt Flight Information Region (FIR), the Buenos Aires VAAC reported that during 16 and 18-19 August ash plumes rose to altitudes of 1.4-2.4 km (4,500-8,000 ft) a.s.l. and drifted NE, E, and SE.
Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN) – “Reports provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”