Reykjanes Peninsula, Spain

Updates on Activity at Fagradalsfjall, Cumbre Vieja, and Askja as of October 2021

We are no longer updating this post; future updates will be included in new posts.

Update 2 12.10.2021: Plots of the Earthquake Swarm SSW of Mount Kelir, 27/09/2021 to Date

Fig 16: Mount Kelir, cropped from an image by Michal Klajban, published under CC BY-SA 4.0.  Source: Wikimedia Commons

Mount Kelir is at the northern end of the earthquake swarm which started on 22 February 2021. In that swarm, earthquakes started near Mount Kelir and migrated towards and beyond Fagradalsfjall prior to the eruption at Geldingadalir on 19 March 2021.

The current swarm which started on 27 September 2021 near Mount Kelir is ongoing at the time of writing.  Over 10,000 earthquakes have been recorded, of which IMO have confirmed c. 1,245.  It is thought that an eruption may ensue near Mount Kelir.

We have plotted the earthquakes and made a video of the geoscatter and scatter plots.

Fig 17:  Analysis of the swarm by depth and magnitude by the author.  © Copyright remains with the author; all rights reserved, 2021.
Fig 18:  Video of geoscatter plots and scatter plots of the current swarm by the author.  © Copyright remains with the author; all rights reserved, 2021.

Whether or not a new eruptive site emerges, magma migrates to the existing site at Fagradalsfjall, or, it all quietens down, only time will tell.  At the moment the swarm is migrating SSW. 

Armchair Volcanologist

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

Source for raw earthquake data:  Icelandic Met Office: IMO

12.10.2021 1: Update on La Palma Seismicity

Good Morning!

Let’s take look at status of the eruption and seismicity at La Palma.

The eruption is still going strong.  The cone has grown substantially, despite partial collapses.

Fig 11: Cone growth.  On the left, the new cone on 20 September, 2021, cropped from an image by Eduardo Robaina, published under CC BY-SA 3.0; on the right, screen shot earlier today from RTVC

The following was reported earlier today:

  • The lava reached the cement works, Callejón de la Gata, today.  Local residents were confined to their homes due to the risk of toxic fumes from burning chemicals.
  • A  large volume of lava was emitted after the wall of the lava lake [cone?] was destroyed.
  • The northern arm of the lava flow is now 300 metres from the sea and expected to make a new lava delta near the beach of Perdido.
  • 591.1 hectares have been affected by lava.  This includes 132 hectares of crops , of which 70 hectares were banana crops; 33 hectares vineyards; and, 8 hectares avocado crops.
  • The maximum width of the lava flow is 1,520 metres.
  • 1,281 buildings have been impacted, of which 1,186 have been destroyed.
  • The lava delta is now 34 hectares.
  • Seismicity remains high.  To  date, over 35,000 earthquakes have been recorded.  The most recent earthquakes remain below 10km, with depths reaching more than 20km.

The high level of seismicity is thought to indicate rising magma because there have been spasmodic tremors and a strong volcanic tremor at 18 Hz; the latter may be from depressurisation of magma at a depth of c. 10km.  In the absence of increased ground deformation, it is not known when or how magma may reach the surface.  If it reaches the surface, it may follow the current conduit or emerge at new fissures.

Fig 12:  Amplitude of seismic signal, source: IGN.  Green line denotes onset of the eruption.
Fig 13:  Seismic signal, source: IGN

We have updated our earthquake data and have plotted the swarm from 27 September 2021to present.  The results are shown in the video below.

Fig 14: Analysis of the earthquake swarm from 11 September 2021 to present by the author.  © Copyright remains with the author; all rights reserved, 2021.
Fig 15: Video showing geoscatter plots and scatter plots by the author of the swarm from 27/09/2021 to present

Armchair Volcanologist

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

Sources:

El Mundo: www.elmundo.es

VolcanoDiscovery:  www.volcanodiscovery.com

IGN: www.ign.es

04.10.2021: Update Fagradalsfjall Seismic Swarm near Kelir

The swarm near Mount Kelir is ongoing.  IMO report that 6.200 earthquakes have occurred in the swarm, although c.624 have been confirmed at the time of writing (Sources:  IMO_Earthquakes and  Skjálfta-Lísa (vedur.is)).

Fig 8: Geoscatter plot of the current swarm SSW Mount Kelir by the author. Colour denotes time (using earthquake number), red is the oldest and yellow the youngest.  © Copyright remains with the author; all rights reserved, 2021

We have analysed and plotted the swarm.  It would appear that the swarm is ascending but still in the crust. The largest earthquake with a magnitude of 4.16 had a depth of 5.669 km. 

Fig 9: Numerical analysis of the swarm by the author.  © Copyright remains with the author; all rights reserved, 2021.

The possible ascent of the swarm is more visible in the scatter plot looking at it in an easterly direction.

Fig 10: Scatter plot of the swarm by the author.  Colour denotes time (using earthquake number), red is the oldest and yellow the youngest. © Copyright remains with the author; all rights reserved, 2021.

04.10. 2021: Update on the Cumbre Vieja Eruption

Fig 6: Plot of earthquakes from 11/09/2021 to 04/10/2021 10:13:11 by the author.   © Copyright remains with the author; all rights reserved, 2021
  • Part of the main cone collapsed at c. 9:10 pm last night; some vents have now merged.
  • Effusive activity has increased.  Lava flows have merged; the flow is 1km wide at its widest point.
  • The lava delta is now 29.7 hectares.  This has impacted the surfing beach at Los Guirres.
  • 400 hectares of land has been covered by lava and 4,819 hectares covered by ash.  1,047 buildings have been damaged, including 947 destroyed.
  • 20% of the banana crop has been lost. The village  of La Bombilla, built for banana plantation workers, is now under threat.
  • The seismic swarm is ongoing, with most recent earthquakes between 7km  – 14km depth.

We have updated our earthquake plots for the most recent swarm (11/09/2021 to 04/10/2021 14:30:59).  The swarm reactivated on Day 17.

Fig 7: Earthquake  plots by the author for the swarm 11/09/2021 to present. © Copyright remains with the author; all rights reserved, 2021

Sources for updates as before: El Mundo and IGN.

01.10.2021 (original post)

Good Morning! Today we provide an update on Fagradalsfjall, Cumbre Vieja (with video of earthquake swarms) and Askja.

Fagradalsfjall, Iceland

Fig 1: Mount Kelir, cropped from an image by Michal Klajban, published under CC BY-SA 4.0.  Source: Wikimedia Commons

Fagradalsfjall celebrated the six-month anniversary of the start of the eruption, which occurred on 19 March 2021, by taking a break.  Low level activity has been observed since 18 September 2021.

An earthquake swarm stared on 27 September 2021 south of Mount Kelir.  This is located near the northern end of the earthquake swarms earlier this year which preceded the eruption at Geldingadalir.

We have plotted the swarm to see what is going on.

Fig 2a: Plots by the author of the earthquake swarm from 27/09/2021 to present. Geodensity plot on the left and geoscatter plot on the right.  The colour code in the geoscatter plot is time: red is the oldest, yellow the newest. Time is approximated by earthquake sequence.  © Copyright remains with the author; all rights reserved, 2021.
Fig 2b: Plots by the author of the earthquake swarm from 27/09/2021 to present. Scatter depth v longitude plot on the left and scatter depth v latitude plot on the right.  The colour code is time: red is the oldest, yellow the newest. Time is approximated by earthquake sequence.  © Copyright remains with the author; all rights reserved, 2021.

While it is not clear what the cause of the swarm is (new magma or the crust adjusting to changes in tension), people are advised to avoid the area for the time being.  If an eruption does occur near Kelir, it is expected to be similar to that at Fagradalsfjall.   The aviation code is still orange.

Cumbre Vieja, Canary Islands

Fig 3: Cumbre Vieja eruption on 20/09/2021, cropped from an image by Eduardo Robaina, published under CC BY-SA 3.0.  Source: Wikimedia Commons

The eruption is still going strong.  The vents have produced ash columns, jetting lava and effusive lava flows.

Lava reached the sea, following the opening of a new vent earlier this week, which emitted more effusive lava. The lava travelled at 300 m/hr, crossing the coastal road and cascading over 100m high cliffs at Los Guirres. The lava is forming a delta, which has reached an impressive size 21 hectares. 

There are now four eruptive vents: a new effusive vent opened 400m north of the main vent on Thursday; and, two more opened on Friday 15 metres apart and 600m north west of the main cone.  Lava from Thursday’s new vent also made it to the sea via a flow parallel to the original one.  A fumarolic field has developed on the north side of the main vent.

Over 80 million cubic metres of lava have been erupted.  Sadly, this has damaged 1,005 buildings, of which 870 have been destroyed.  30.2km of road has been impacted, of which 27.7km have been destroyed.  Ash now covers 3,172.9 hectares of land.

SO2 levels are higher but not considered a risk for the population at the moment.

Earthquakes are occurring near the area start of the swarm which preceded the eruption.  They are deeper than the earlier swarm leading to concern that lava may be fed from a deeper reservoir.   We have plotted the current swarm and previous swarms from 2017 to date. 

Fig 4: Plots by the author of the most recent earthquake activity at Cumbre Vieja.  For plotting purposes, the activity has been labelled as a new swarm, which started on 27 September 2021. Green circles are the current swarm earthquakes < 3.0M; red stars are current swarm earthquakes ≥3.0M; grey circles are earthquakes < 3.0M from 2017 to 26.09.2021; and cyan stars are earthquakes ≥3.0M from 2017 to 26.09.2019 (all are in fact from the previous swarm starting 11 September 2021).  © Copyright remains with the author; all rights reserved, 2021.

We have compiled a video of the earthquake swarms from 2017 to present.

Fig 5: Video by the author showing the progress of the earthquake swarms from 2017 to present. © Copyright remains with the author; all rights reserved, 2021.

Askja

Seismicity is still occurring.  The Icelandic authorities are continuing to monitor this.  The aviation code is still yellow. 

We have not had time to update our earthquake plots, but will do so in due course.

Armchair Volcanologist

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

Sources:

Plots are the authors own work.

Information and raw earthquake data:

Fagradalsfjall: Home-page – Icelandic Meteorological Office | Icelandic Meteorological office (vedur.is)

Cumbre Vieja: Instituto Geográfico Nacional (ign.es) & EL MUNDO – Diario online líder de información en español