Tag Archives: Eruption

Iceland, Spain

La Palma, Update 26.10.2021

Good evening! 

New Earthquake Plots

It has been a week since we updated our last earthquake plots for La Palma so time to take another look.  The eruption has continued in the meantime, with seismicity and seismic signals increasing.  Earthquake activity continues mainly within the two levels 7 -16km and 30 to 42km identified in our previous plots.

Fig 1: screenshots of the eruption 26.10.2021 from local webcams: left, TV Canarias live stream (source: https://www.youtube.com/watch?v=INvrtMg5tSQ); and, right, Hotel Galeon (source: https://eruption.acme.to/slideshow.php?getcam=hotelelgaleon)  (still photos).

Several partial collapses of the main cone have occurred.  The latest was yesterday, releasing a large amount of the lava to the west, which went over existing lava flows.

The latest statistics reported on 26th October 2021 are:

  • 908.2 hectares of land have been affected by lava. 
  • 2,162 buildings haven been destroyed by lava, with a further 124 suffering damage.
  • 66.2km of roads have been lost, with  a further 3.4km damaged.
  • 6,800 hectares of land have been covered by ashfall (reported 22nd October 2021).
  • Cost of lost banana plantations c.100m Euros, 150 hectares are under lava and others are in the exclusion zones; other crops, vineyards and livestock farming are also impacted.
  • SO2 emissions 40,800 tons per day. CO2 emissions up.

In the last 24 hours ground uplift of 10cm has been recorded at the station on the south of the volcano near the eruption site, which the volcanologists monitoring the eruption think may signal an increase in lava flow or the opening of a new vent.

Fig 2: Ground deformation at the station nearest the eruption site.  We have circled the latest data point to make it easier to spot.  Green line marks the onset of the eruption (added by IGN). Source: IGN
Fig 3: Seismic signal today.  Source: IGN

Recent Seismicity

Fig 4:  Plot by the author of earthquake number by day; Day 1 is 1 October 2021, Day 26 is 26 October 2021.  © Copyright remains with the author; all rights reserved, 2021.
Fig 5:  Plot by the author of earthquake depth and magnitude by day; Day 1 is 1 October 2021, Day 26 is 26 October 2021.  © Copyright remains with the author; all rights reserved, 2021.

We have made geoscatter and scatter plots of the swarm from day 21, the onset of the deeper earthquakes.  We have also made plots of the earthquakes over 3.0M, as these tend to get lost in the in the middle level swarm (7-16km). 

Fig 6: Geoscatter and scatter plots of the earthquakes between 1st October 2021 and 26th October 2021 (08:06:14) by the author.  © Copyright remains with the author; all rights reserved, 2021.
Fig 7: Geoscatter and scatter plots of the earthquakes greater than 3.0M between 1st October 2021 and 26th October 2021 (08:06:14) by the author.  © Copyright remains with the author; all rights reserved, 2021.

There are now a few earthquakes between the two swarms but little in the way of reported earthquakes heading for the surface; the latter may mean that lava is flowing freely through the existing conduit, or that a new conduit may be in the offing.  The hike in ground deformation reported above near the eruption site may indicate that whatever ensues, it is likely to be near the current eruption site – speculation on our part.

The eruption is now in its sixth week, lasting longer than recent previous eruptions, with no sign of waning. Has the initial eruption of magma created the right conditions for new magma to erupt from a greater depth, e.g. by creating a pathway for it and/or removing some of the constraining pressure? Only time, and a lot of research by the experts, will tell.

Armchair Volcanologist

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

Sources

News reports: El Mundo,  https://www.elmundo.es  and El Time, https://www.eltime.es/

Raw earthquake data: Instituto Geográfico Nacional (ign.es)

Iceland, Reykjanes Peninsula

Krýsuvík Volcanic System, Aviation Code Red; A Volcanic Eruption Has Started Near Fagradalsfjall, Iceland

1 Comment

Good Evening,

19.03.2021

Fig 1: Eruption at at Geldingadalur. Image from IMO: A volcanic eruption has begun | News | Icelandic Meteorological office (vedur.is)

This was going to be a post with an update on the earthquake swarm on the Reykjanes Peninsula, but the magma beat me to it!  IMO has just confirmed that a volcanic eruption is underway near Fagradalsfjall at Geldingadalur.  The eruption started at 20:45 19.03.2021. It has been named as Geldingadalsgos, after the valley.  At the time of writing, the eruption is a small fissure eruption; the fissure is c. 0.5km long.

Fig 2: Hópsnes Lighthouse, Grindavik looking towards the Fagradalsfjall system.  Image cropped from one by Martin Morris, published under CC-BY-SA 2.0

The public have been  advised not under any circumstances go close to the eruption site or on Reykjanesbraut. First responders need to be able to drive freely to assess the situation. Scientists are working on assessing the eruption, the site and possibilities.

People living nearby in Þorlákshöfn have been instructed to stay indoors, close windows and turn up their heating to avoid exposure to any volcanic gases.  The Reykjanesbraut has been closed – the main road from the capital region to Reykjanesbær and the international airport at Keflavík.

Fig 3: Aviation code red; source IMO.
Fig 4: IMO’s confirmation of the eruption (third warning down). This is an extract from a screenshot of the page.

Here are the updated earthquake plots by the author, anyway.  The raw earthquake data has been obtained from IMO; this is confirmed earthquakes to date (19.03.2021 15:00). IMO’s page above gives the more recent earthquakes.

What we see from the plots is that seismic activity has now extended beyond Reykjanes to the west and the swarm is still active.  Activity in the swarm is densest to the NE and SW of Fagradalsfjall.   The depth plot shows that earthquakes in the swarm are tending to be smaller and shallower.

Extension of the swarm to the west is in keeping with the swarms which have occurred since December 2019. 

Fig 5: Geoscatter plot of the earthquake swarm by the author from 22.02.2021 to 19.03.2021 (15:00).  Colour indicates earthquake number from 22.02.2021. © Copyright remains with the author; all rights reserved, 2021.
Fig 6: Geodensity plot of the swarm between Svartsengi and Krýsuvík. by the author from 22.02.2021 to 19.03.2021 (15:00).  © Copyright remains with the author; all rights reserved, 2021.
Fig 7: Scatter plot of the earthquake swarm by the author from 22.02.2021 to 19.03.2021 (15:00).  Colour indicates earthquake number from 22.02.2021. © Copyright remains with the author; all rights reserved, 2021.
Fig 8: Scatter plot of earthquake depth v time (earthquake number in the swarm) by the author from 22.02.2021 to 19.03.2021 (15:00).  © Copyright remains with the author; all rights reserved, 2021.

Let’s hope that this is a “tourist eruption”; our thoughts are with anyone affected by this eruption.

For more up to date information, please consult IMO or the Department for Civil Protection.

The Armchair Volcanologist

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

Sources:

Plots by the author.

Source for raw earthquake data: IMO

Icelandic Meteorological Office – IMO (@Vedurstofan) / Twitter

Department of Civil Protection and Emergency Management | Almannavarnir