Good evening!

There was some good news for La Palma over the week end; the eruption was declared over on 25 December 2021.  The eruption, itself, ended on 13 December 2021 at 22:21.  There was a precautionary period of waiting before announcing the end of the eruption.

This is an important milestone in the process to recover and rebuild.

Statistics

Eruption

The eruption started on 19 September 2021 as a flank eruption on the Cumbre Vieja volcano and ended on 13 December 2021.  The duration of the eruption was 85 days and 8 hours – the longest for which there are historic records.

The eruptive style is described as Strombolian fissural with phreatomagmatic pulses.

The average height of the plume was 3.5km and its the maximum height was 8.5 km on 13 December 2021.

Edifice

The cone’s height is now 1,121m.

There are six craters, with diameters ranging between 106m and 172m.

Lava

200 million cubic meters erupted, covering an area of 1,219 hectares with an average thickness of 12m and maximum width of 3,350m.

The maximum temperature was 1,140°C.

Two lava deltas were created covering c. 48 hectares (one c. 43 hectares and the other 5 hectares).

Damage

2,988 buildings were destroyed and 138 damaged, according to satellite data. This is initially analysed by the local authorities as 1,345 residential properties, 180 agricultural, 75 industrial, 44 leisure, 16 public and 16 other; the shortfall is attributed to properties having more than one building within their boundaries.

Infrastructural damage includes: 73.8 km of road have been damaged along with streets and crossings; and, 130km power lines, 85 medium voltage towers, 1500 low voltage poles and 19 distribution centres.

We do not have an up to date analysis of the extent of the damage to crops and livestock.

Around 7,000 people were evacuated.

There was sadly one fatality which is under investigation.

Seismic Activity

9,135 earthquakes were recorded in the period from 11 September (the onset of the swarm) and today, 27 December 2021.  Due to the severity of the volcanic tremor, many smaller quakes were not recorded.

We have plotted the sequence.  The results are shown in the video below.

 Earthquake activity is continuing at the time of writing.

Armchair Volcanologist

© Copyright remains with the author; all rights reserved, 2021.

Sources:

El Time: ElTime.es

Raw earthquake data: Instituto Geográfico Nacional (IGN)