The eruption continues as in the previous days, with a Strombolian mechanism with a predominant effusive phase and a weaker explosive phase. More explosive activity continues to be concentrated in multiple vents within the main cone, and the effusive outlet is seen as a stepped lava channel that runs down the northern flank. The ash emission vent on the SE flank which reactivated on the 16^th October continues intermittently. The active lava flow to the south of La Laguna Mountain, closest to the coast, has slowed to 2 m per hour and is currently 160 m from the coast. Elsewhere, advance of the flow front located just above La Laguna has largely stalled for the moment, although the flows continue to widen and thicken. Between 2pm-9pm local time, it was advised in El Paso that the population stay indoors due to unfavourable PM10 concentrations. This was due to the influence of the Saharan air mass, the ash from the volcano, and also the persistence of a low thermal inversion, which is expected to persist until the 22^nd October. However, ash dispersion was more favourable than previous days with respect to the operation of La Palma airport.

SO2 concentrations remained below threshold levels throughout the day at all stations. PM10 concentrations remained elevated in all stations due to the presence of the Saharan air mass and also the eruption in the stations in the Aridane Valley, with the daily threshold (50 μg/m³) being exceeded in all stations on the island. Earthquake activity remained similar to previous days and contained both intermediate (10-15 km) and deep (>20 km) earthquakes. 90 events were recorded, peaking at 4.3 mbLg. Deformation remains stable at stations closest to the eruption. The ash and gas plume reached 4000 m, and the SO2 emissions from the volcano were within ranges seen in previous days, at 9,938 tons per day, although this is an underestimate.

A satellite image showing the progress in the lava flows in the last few days. The progress of the flows to the north of the flow field can clearly be seen. Image credit: Copernicus EMS

Sources: Government of the Canary Islands, PEVOLCA, Involcan, IGN, DSN, Cabildo La Palma, 112 Canarias, Tolouse VAAC, Copernicus EMS