SERNAGEOMIN reported that seismic tremor coincided with the onset of gas emissions and the ejection of pyroclastic material from Llaima on 1 January. Within a few hours, a Strombolian phase began. An increase in volume of the Captrén River on the N flank was observed. On 2 January, small emissions of ash and gas (mainly steam) and three small lahars on the N and W flanks were observed during an overflight. Tremor also decreased and an explosion was observed. Based on pilot reports and observations of satellite imagery, the Buenos Aires VAAC reported that an ash plume rose to an unconfirmed altitude of 12.5 km (41,000 ft) a.s.l. and drifted E on 2 January. A lava flow on the E flank was also noted.
On 3 January, another overflight revealed that the explosion that occurred on the previous day took place from an area high on the E flank and not from within the crater. Emissions of gas and ash were small and sporadic. The Buenos Aires VAAC reported that an ash plume was visible on satellite imagery at an altitude of 3.7 km (12,000 ft) a.s.l. and drifted NE.
Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN) , Buenos Aires Volcanic Ash Advisory Center (VAAC) – “Reports provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”