For the first time since the 20^th November, air quality has been sufficient enough to allow the commencement of operations at La Palma airport. The change in air quality is due to a change in wind direction, with dispersion of the volcanic plume now being to the southeast. The lava flow activity remains largely concentrated in the central flows which are widening, as well as in the stream at the south of the flow field which was fed by the inactive vents to the south of the main cone and advances incrementally. Seismicity remains similar to previous days, with 75 events being recorded with most being intermediate (10-15 km depth) events although some deep (30-45 km depth) events were recorded. The day’s largest earthquake which was a mbLg 3.6 event at 36 km depth.

Volcanic tremor is low, whilst deformation now remains stable across the whole network except for some possible deformation signals at the station nearest the volcano, but these also show signs of meteorological origin. SO2 emissions were measured at a ‘very high’ level (30,000-49,999 tons per day), whilst the plume height could not be measured due to the poor weather. As a general trend however, satellite measurements imply current SO2 emissions are lower than the start of the eruption. Air quality with respect to SO2 exceeded the daily limit threshold (125 μg/m³) in Los Llanos, and other instances of brief peaks in concentrations were seen in Tazacorte. All other stations retained good or reasonably good values with respect to SO2 levels. PM10 levels were better, with good or reasonably good levels in all stations throughout the day.

(Above) Degassing of the active lava flows on the 27th near La Laguna Mountain, which are widening and thickening the existing flows in the area. Video credit: INVOLCAN

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