Cumbre Vieja and the San Juan eruption of 1949

The volcano Cumbre Vieja in the island of La Palma has been showing signs of unrest. The question on everyone’s mind is, will there be an eruption? Maybe, or maybe not. This is always hard to know.

The Spanish National Geographic Institute reports inflation, a total of 10 cm of deformation. As such it is evident that there is magma on the move under Cumbre Vieja, it has intruded underneath the volcano.

https://www.ign.es/web/ign/portal/noticias

There have been multiple swarms of earthquakes since 2017 in Cumbre Vieja, a total of nine. Previous swarms were probably magma intrusions too, but which did not reach the surface. The recent swarm however is more shallow and more intense than its predecessors which raises the possibility that the outcome may be different.

The current swarm started on September 12. A total of 4530 earthquakes have been detected at depths of mainly around 10 km, although there are a few which have been very shallow. The swarm commenced under the summit of Cumbre Vieja, where a magma conduit probably exists which is supplying the intrusion. Earthquakes have propagated to the northwest. This probably represents the propagation of magma filled fractures, possibly sills, radially from the centre of Cumbre Vieja. However the earthquakes only show a but a blur of what is going on down there. The exact shape and pathways used by the intrusions cannot really be known with much precision. It is somewhat similar to the prelude to the eruption of El Hierro in 2011 which also seems to have commenced with a sill that later propagated a crack towards the seafloor.

Image from the NASA.

The location of the earthquakes suggest a possible eruption in the NW sector of Cumbre Vieja. However there is a factor of unpredictability. The exact path that the intrusion takes may or may not connect with the surface, such being difficult to know if there will or will not be an eruption . The precise location where the intrusion will breach the surface is also difficult to know. The fissure could open in the middle of a town, in a forest, or it could open underwater, which are wildly different situations with wildly different consequences.

We can know however the style that the next eruption of Cumbre Vieja will take, whenever and wherever it happens. To do this we must look at the past history of this volcano.

 

La Palma

La Palma is one of the Canary Islands. It was formed due to volcanic activity. The oldest rocks of the island are 3-4 million years old and belong to a submarine volcano. These submarine lavas are now found at heights of up to 1500 meters above sea level in the Barranco de las Angustias, in the old northern part of the island, which shows the enormous uplift that the island has undergone. Probably numerous sill intrusions have pushed the volcano upwards.

La Palma. From the NASA.

La Palma is shaped like an arrowhead. The northern part is formed by the old Taburiente volcano. Deep gullies dissect the ancient lava flows exposing the overlapping layers of volcanic extrusions and the frozen dykes and sills which cut through them. The volcanic edifice was destroyed by a series of giant landslides, the last of which took place around  560,000 years ago. Activity continued inside the landslide scarp until 530,000 years ago. Afterwards activity died out in the northern half of the island.

Large scarp formed due to erosion of Taburiente volcano. Some sills and dykes are visible on the left. From Wikimedia, by Zyance.

Volcanic activity in the southern half of the island has been ongoing for at least 125,000 years and has constructed another volcano known as Cumbre Vieja, or also simply as Dorsal Sur, “Southern Ridge”. It is a shaped like a ridge in a N-S direction. Despite being different edifices it seems that Cumbre Vieja is part of Taburiente’s structure. Taburiente had 5 subtle radial rifts. This is much better appreciated in submarine shield volcanoes which are often shaped like ridges or like three to six-pointed stars. Knowing well the shape of submarine volcanoes I can see that Taburiente displays the same five-pointed star structure, although being subaerial it is not so easily visible. The longest, dominant rift goes southward, known as Cumbre Nueva. It can be seen that Cumbre Vieja is the southern continuation of Cumbre Nueva.

Topography of La Palma. Note the northern volcano Taburiente which is cut by deep gullies and a central erosional crater, and the southern volcano Cumbre Vieja which is dotted by young volcanic cones. There is a bow-shaped ridge connecting both volcanoes, this is Cumbre Nueva, the ancient rift zone of Taburiente, partly destroyed by a landslide. From maps-for-free.com.

 

The main magma erupted in La Palma, as well as in the Canary Islands, is basanite, which is relatively fluid, but not as much as say Hawaii. The fluidity is comparable to the more frequently active Mount Etna in Sicily. The magma is not so fluid that all of it would flow away upon landing on the surface, but it is not so viscous that it is entirely blasted into light pumice and ash carried away by the wind. The eruption style is known as “violent strombolian” or “violent hawaiian” depending on whether it produces explosions or sustained fountains. It is the middle ground between the blazing rivers of lava and the billowing columns of ash. This style is ideal for producing pyroclastic material that rains around the fountain, rapidly constructing a mountain around the vent, known as a scoria cone. These conical mounds of ejecta are everywhere over Cumbre Vieja. Because the volcano doesn’t have any central vent that erupts repeatedly, then it makes a new fissure each time it erupts. The pyroclastic material rapidly oxidices. This gives the terrain various hues ranging from black to red, which together with the abundant canarian pine trees gives the characteristic landscape of Cumbre Vieja.

Desertic volcanic landscape near the southern point of the island. San Antonio volcano visible in the centre formed in the 1677 eruption, The brighter cone to the left of San Antonio is Teneguia, which formed in 1971. From Wikimedia by Tony Hisgett.

Other magma types present in Cumbre Vieja are the tephrite and phonolite groups which are more silicic and viscous. They are  present in trace amounts making small lava domes. A small volume of phonolite was emitted in 1585 producing tiny cryptodomes and domes, although the eruption was mainly basanitic.

Types of volcanic rocks depending on silica and alkali content. From Wikimedia by Woudloper.

Cumbre Vieja last erupted in 1971, 1949, 1712, 1677, 1646, and 1585. It is the most active volcano in the Canary Islands. Eruptions have taken place at intervals of 20-60 years. The exception being the remarkable 237 years long dormancy between 1712 and 1949. Why did this happen? It is possible that the volcano follows cycles of more frequent eruptions separated by long dormancies. Another possibility is that the enormous 6-year long eruption of nearby Lanzarote Island, occurring in 1730, induced a long dormancy in Cumbre Vieja.

It would not be unexpected that now, 50 years after the last eruption, there was a new one.

The eruption of 1949

The eruption that took place in 1949 is an interesting example of a typical Cumbre Vieja eruption.

Swarms of earthquakes had been frequent since 1936 and leading until the eruption. The morning of June 24 some fumes were noticed, and soon afterwards a towering black column of ash was rising hundreds of meters, if not more, into the sky. A new volcano had formed along the crest of Cumbre Vieja. The fissure had opened a small distance north of the highest point of the ridge. The vent is known as Duraznero.

During the following days Duraznero continued to erupt, belching out ash and rocks. Earthquakes frequently rocked the nearby communities and steaming fractures opened in the  ground around Duraznero. Magma must have been making its way into growing fractures. Over the days the erupting fissure progressively grew to a length of 500 meters and developed 5 main vents, of which Duraznero 2, at the southern end, was the most active, creating a 170 meter-wide crater. The activity was entirely explosive but of a low intensity that must have been little more than a slight annoyance to the local population. The erupted lava was tephrite. Earthquakes were more impactful, they damaged houses, cracked roads, and occasioned rockfalls. On July 6 the ash was carried downwind over the island of Tenerife where it wrapped around the summit of El Teide in a menacing black cloud.

Fissures of Duraznero. Image by KrisNM.

On July 8 a stream of lava came out from a new location known as Llano del Banco, 3 kilometres north of Duraznero, and from the other end of a system of cracks that had opened up. It did so quietly with no explosive activity whatsoever. The lava must have been degassed by Duraznero, gone into cracks, and found an outlet at a lower elevation from Llano del Banco. The lava erupted was tephrite, same as that of the earlier phase of the eruption. The initial fissure died out at about the time the new vent opened.

It is common for eruptions of Cumbre Vieja to have some vents which are dominantly explosive while others are effusive. In the eruptions of 1646, 1677 and 1712 it also happened that the vents which opened at the highest elevations had explosive activity and built large cones of scoria, while other fissures opened at lower elevations, sometimes offrift, and even at sea level, producing solely lava flows. The eruption of 1949 shows how the process works. A vent that is high up degasses the magma and then it is carried laterally through fractures towards openings downslope from which it emerges effusively.

Lava descended in fiery tongues from Llano del Banco down the flanks of the mountain. People were being evacuated as the flow headed for populated areas. It took 10 hours for the lava to reach the main road of the south of La Palma. Later that day the flow had destroyed 20 structures, including houses, cellars, and barns.

On July 10 lava cascaded over a cliff into the ocean. From this day on the entry of lava into the sea became continuous, and a lava delta was gradually constructed. Cloud of steams rising over the waters were illuminated by the convoluted streams of incandescent rock.

A new change in the eruption took place on July 12. The composition of lava erupted from Llano del Banco changed from tephrite to basanite. It became less silicic. At a similar time a new vent opened 400 meters north of the initial vent of Duraznero in the location known as Hoyo Negro. Black cauliflowers of ash pierced with flashes of lightning rose rhythmically from the Hoyo Negro vent. It erupted various magma types including basanites, tephri-phonolites and phono-tephrites. Once again the vent uprift was explosive while the vent downrift was effusive. The basanitic magmas must have released their gas into the explosions of Hoyo Negro and then come out laterally through the opening in Llano del Banco.

Hoyo Negro projected bombs to a distance of 1 kilometre from the vent snapping the trees and setting portions of the pine forest on fire. Clouds of ash frequently dusted the western part of the island. The explosions excavated a 400-meter wide crater on sloping ground. This created a spectacular 200-metre cliff against the higher side of the slope, which exposed the many layers of ejecta painted in a variety of colours.

Hoyo Negro. Image by Rafael Medina.

A raging stream of lava continued to issue from Llano del Banco and cascade towards the coast. Despite erupting continuously for 18 days the vent produced no distinguishable ejecta, and shows how the gas had been entirely removed from the melt before erupting. The ground above the fissure collapsed among loud noises, the rocks fell into the stream and were carried away, a length of 150 meters of rock above the conduit was eroded away and disappeared leaving behind a deep chasm in the forest.

On July 22 the activity of Hoyo Negro was down to a solfatara. Llano del Banco was also dying down. By July 26 the eruption had fully stopped.

Early on the morning of July 30 the eruption suddenly resumed. Duraznero and Hoyo Negro exploded simultaneously. An hour later fluid basanite lavas emerged from the location of Duraznero 1 and poured into an old crater where it formed a lava lake which then overflowed and formed a narrow stream of lava that rapidly sped down the steep slopes of Cumbre Vieja, cutting the road of Santa Cruz de la Palma, and nearly reaching the sea after 11 hours of advance, when the eruption came to a stop. This was the last episode of the 1949 eruption.

The flow of July 30, although of rapid advance, it was fed at a rate of only 10 m3/s, which is very low. It was also similar to the mean eruption rate of Llano del Banco, which was approximately 14 m3/s. The explosive activity was of little volume so it probably does not change the overall numbers too much. As such the eruption of 1949 was of very low intensity, in both its effusive and explosive counterparts. Slow eruptions are typical of the Canary Islands. Such low intensity eruptions do not pose much of a hazard to the people, in fact no one died in the 1949 eruption, despite 120 houses or so being destroyed, and people having approached the eruption in order to view it. This doesn’t mean that the hazard is inexistent.

If someone stands very close to the vents he/she could be asphyxiated by the noxious gasses or may be impacted by a lava bomb or by lightning. Rarely when lava flows reach steep slopes they collapse into blistering landslides resembling small-scale pyroclastic flows that could potentially kill someone. Conditions around volcanic eruptions can change suddenly in unpredictable ways and become hostile to humans. Safety is not guaranteed.

If Cumbre Vieja erupts in the future it will probably resemble the 1949 eruption in many ways: an earthquake prelude to the eruption that may deal damage to structures, unpredictable opening of fissures, some vents producing mainly explosive activity while others feeding mainly streams of lava that destroy human properties, and also the likely entry of lava into the sea.

Of course if the current earthquake swarm will culminate in an eruption or not cannot be known for sure. Swarms before the 1949 eruption occurred as early as 1936 and did not culminate in eruption until 13 years later.

 

San Martin volcano, formed in a 1646 eruption. Image by Rafael Medina.

 

Interesting links

Eruption of 1949 (in spanish).

IGN news (spanish).

GRAFCAN visor (includes geologic and topographic maps).

 

1,260 thoughts on “Cumbre Vieja and the San Juan eruption of 1949

  1. Just seen an advisory for Katmai. I know Pavlof, Semisopochnoi and Sitkin have been erupting away of late but Katmai hasn’t budged since Novarupta 1912.

  2. Saw some drones flying closer to the vent on this one, would like to see what they filmed…

  3. Última actualización de la evolución de la lava, con cálculos aproximados a vista de satélite

    ▪ La lava se encuentra a 2,5 kms aprox del mar
    ▪ Más de 200 viviendas dañadas
    ▪ Más de 100 hectáreas afectadas

  4. As a very amateur volcano watcher, I’m curious as to how come the lava flow front in the La Palma eruption is so high. It didn’t seem that high at any of the other eruptions I’ve watched or is that just perspective or does it have something to do with the gradient of the mountain? Also, is all that loose stone rubble that coats the lava flow the topsoil from the mountain? It doesn’t look like pahoehoe or aa. There’s no such thing as a stupid question but I may just have found it. 😀

    • 1. It’s more viscous, and was erupted at a cooler temperature, lost most of its gas, and flowed on a more-or-less consistent gradual slope. Kīlauea’s1977 eruption was unusual because it had these same characteristics. Unusual for Kīlauea, not so unusual for Cumbre Vieja. The lava should get more ‘runny’ later.
      2. I haven’t seen any pāhoehoe yet, it’s all ‘a’ā. What you see on the top of the flow could possibly be the bottom layer further on.

    • The lava is quite cool. It is liquid underneath but when the liquid gets close to the surface it cools and stops. This gives a bulldozer effect, being pushed from behind rather the flowing from the front.

    • Very interesting thanks-proves that La Palma lava can be very fluid-unlike present conditions.

  5. This drone film gives an idea of the hilly geography of Todoque, where the lava front is right now.

    Francesc Domènech (@ffdomenech) Tweeted: #Todoque #LaPalma
    https://t.co/czVPbmp9Dp

    Hope I’ve linked it correctly

  6. Rare earthquake here this morning in SE Oz at Richter c.6.0. Jack Russell none best pleased. My chimneys are still vertical. None of the many local volcanic cones is showing signs of life.

    • Some have reported felt it in Sydney-not I though. The only one I ever felt was the 1973 quake south of Sydney.

      • I didnt feel it from Tasmania, I actually thought it was a joke when I first saw it until it appeared on the news. Mag 6 might be our biggest recorded quake too, at least actually on the continent.

        Did think about the volcanics of the area, around Melbourne it is way older than further west but 6 magnitude quakes are not exactly common either.

    • RE: “Rare earthquake here this morning in SE Oz…”

      Have friends in North Caulfield, Melbourne. They’re all shook up. No damage. I was down there in late Oct/ early Nov 2017 for a fortnight stay with them. Traveled by road Sidney>Melbourne through Canberra and into the Blue Mountains. Where are the local volcanics? I bet they have no idea.

      • There’s heaps in Victoria – alas alot of Australians have poor knowledge of them- never mentioned when I was at School.

        • Thanks for the get back, David. I followed up on this via Google. I could make a great road trip out of the findings.

          • Love to explore them properly-love Mt Gambier and Shank too.

      • Newer Volcanics, an old and very large volcanic field that goes between Mt Gambier and western Melbourne. it is still active too, a few thousand years between eruptions, so while not a big risk it is not entirely out of the question for an eruption in the near future. The majority of the field is made of tholeiite basalt simialr to that of Iceland and Hawaii, so seems to have been a prolific area up until around a million years ago, eruptions now are more alkaline.

        There is also McBride, also known as Undara, up in Queensland. It is also active in the Holocene, and is a massive very flat shield volcano. It has also not yet entered its tholeiite stage, which the neighboring Atherton province did in its evolution, so this area is one with a big future. Intervals between eruptions here seem to be a bit longer but eruptions are massive, comparable to the biggest of Icelandic shields,

        • Yes Chad quiet right-,mustn’t forget Queensland–it has a not so ancient history of volcanic eruptions .Always wondered if Queensland will be the next site in Australia for an eruption-esp as the continent is moving north -and a cross over the ring of fire.I know it’s not as simple as that – when O when.

          • Well not for that reason, but Undara and Atherton are both just as active as Newer Volcanics, and the magma source must be robust to fuel such big eruptions. I think there is an actual magma chamber under Undara, as in it is a central volcano, just an embryonic one.

        • Glad I am not a worry wart Chad. As I am surrounded by a ring of seven plus prominent calderas, all a bit weather worn these days, this morning’s jolt could keep me awake at nights. At the time the house began to move and the rumbling intensified, I was on the phone to the clinic arranging tomorrow’s Covid clot shot.
          There was a muffled shriek from the other end and we then turned to discussing our respective oscillations.

          • The earthquake appears to be related to tectonics of the south australian mountains. It is not related to the new volcanics which are further west.

          • Yes, saw the map, it is nowhere near the volcanoes at all. I guess it is a reminder that the east coast of Australia is a so called active passive margin just like the rest of the west pacific continental margins.

  7. Grimsvötn has had a few quakes lately and the CSM graph is starting to rise steeply again, can’t be long now

    • Grimsvotn or Kilauea, the big rivalry of last year. We know which was the winner then but now is round 2… Though I think personally it is a battle for second place, after Etna 🙂

    • Chad…

      Grimsvotn have accumulated quite alot of magma since 2011

      Will the next eruption be of lower intensity and more longer lived than 2011?

  8. Regarding the fate of the center of Todoque this photo is shared on Twitter. It shows on the left the prominent yellow building diagonally opposite the church. The apparently very slow lava is now where the bulldozer was working yesterday. If it stops now many houses would be spared.

    • Quinauberon
      This is very viscous massive stuff ..

      Do you think the flow core is pasty enough to be penetrated by a pipe?

      • No idea, I’m not a volcano expert whatsoever. When it comes to the destruction in Todoque my guess is that faster lava would have been better, leading perhaps to narrower streams, but Im not sure. Once the lava would reach the cliff to the sea there would be an established stream with not much intention to grow to the sides? Please correct me if I’m wrong.

      • It will be fun If this huge masses of Aa lava reached the sea without too much destruction

        That lava will be very very steamy in the ocean and crazy sight when it will tumble over the 100 meter tall seacliff .. huge red hot blocks gets swallowed by the cold Sea and pheratomagmatic explosions sends debries everywhere

      • Wow .. this lava is Viscous for being ultramafic, but its because its cold

        This street lava is as Viscous as some Basaltic Andesites and some close to vent andesites, blurs the diffrences between mafic and higher sillica flow behaviour

        Still near the vents This is quite fluid about same as Etnas

        • What strikes me is how ‘cold’ the lava seems to be. Many houses that are just ‘touched’ by the stream are not burning. Even if owners have to give up their houses, some may still be able to save parts of their household (and thus part of their memories). Only a little comfort though.

      • Well its ultrabasic.. about 40% sillica I think ..

        But cold and stiff
        These thick Aa flows will take many many years to loose their internal heat
        Etnas 2001 thick Aa lava is still around 60 C inside and can sometimes be steaming a little in winter

        The Canary flows might just get moving anyway .. their huge rocky masses retains heat very well .. so They will continue to move as long as they are feed

        Insulating crusts and extremely low heat conductivity is why some prehistoric lava flows have flowed almost 2000 km in India

      • An aa lava flow is, if anything, relentless.
        As long as it is being fed, there’s not much stopping it, really.

      • Quinauberon

        Lava haves very vey very low heat conductivity. That means that the crust rubble insulates very well indeed.
        The crust on these flows maybe less than 100 C perhaps room temperatures.

        You coud probaly toutch the rubble of these moving flows without pain .. althrough very hot inside and at the flow front

      • Trees too Thats mostly water resist lava for a long time

        The lava chills an insulating shell around the cold tree and it can stand for hours even days as the lava flow around it. But they in princip always dies and burns through Leaving holes behind in the flow. In thick Aa flows like these there is too much heat around it leaving No chance

        Some thick trees have even surivived short lived fluid lava glass floods in Hawaii and Congo .. with the living trunk still hanging on the cooled shell of lava.

        Trees killed and burned by fast moving fluid lava floods are called ”tree casts” ”lava trees” they are common in Hawaii

      • Was is me, at the beginning of the video does it look really clear that a lot of the houses are built upon old lava flows that look very like the current ones, just overgrown with bushes?

        I couldn’t watch much of this video because it made me dizzy with the continuous right turning. Anyone else feel like someone was telling the drone driver to pan left but they kept turning right?

        It’s a pity because it was a good overview, but it would have been nice for the shots to linger a little longer on the lava fronts, because I think there were some good views of where the lava might go next.

        • I guess one purpose of the flight was to document the ‘old’ Todoque. So that people can see how things were just before the lava came.

          • The old lava flows would have told me precisely where NOT to build.

          • Good point. It’s didn’t feel like the main purpose was to look at the lava!

  9. The air is still- dark plume going straight up and air quality is very poor- a depressing atmosphere for the locals I imagine.

    • It breaks your heart. Relentless is the word. The only way to stop it is by cutting off the supply. That will happen at some point but that is not much consolation for people whose homes are being demolished. At least the people themselves are safe. This makes me think of the images from the Vesuvius eruption in 1944

    • I hope the guy filming that stayed well away from the building. The building collapsing across the road looked more dangerous than the lava!

      • Yes, the ‘green house’ collapsed now partly onto the street. Source: Everywhere in Twitter in 5 minutes (don’t know why everything has to be copied 1 Mill times).

    • the supply does not seem to be stopping just yet, but at least the inflation trend at LP03 seems to be ending. 24cm is enough.

  10. (The following comment was found in the suspected spam, from denaliwatch. It is worth saving. I have put in a new comment since otherwise it would be lost in previous comment pages)

    If you google albumdelasmanchas dot blogspot dot com with San Juan you get some impressive photographs from 1949. Wasn’t able to link it.

  11. It looks like the eruption is pretty much entirely explosive now, the lava fountains are jetting very high and are ashy in daylight. The lava flow might still be fed but it is hard to tell, the effusion rate in general though has gone up because the tremor is now much hogher than at any point before during the eruption.

    I would guess that last part is either related to fountaining or is related to shallow magma movement of more fluid lava trying to find a way out downslope.

    • Yes, it does, as well as the other 2 or 3 charts showing activity in the Canary Islands. The seismographs are picking up the explosive energy of the vent on La Palma, and it’s showing up quite far away. There was a period of time where the explosive bursts were very active, I saw white smoke blown out of vent #2 at least 3 or 4 times, a sign of very high pressure in the vent conduits.

    • I guess this is only based on historic eruptions that had a maximum lifespan of such time, this is somewhere discussed before.

    • This is the ‘green house video’ from the morning. The ‘green house’ did actually withstand for quite some time. There is a new drone video from 1500 on the market (already shared 1000000 times on Twitter), showing that the lava is very slowly approaching the unfinished building across the street from the restaurant.

      Authorities constructed a naive stone barricate towards the church and demolished the walls of the empty space past beyond roundabout, maybe to make it easy for the stream to go there.

      https://www.youtube.com/channel/UCA3x4hQV5Wa7xqYxkVNEmNQ/videos

      • ‘past beyond roundabout’: What I meant was ‘beyound the roundabout’. See, the walls are dmolished. If lava can float there without much resistance it might not want to work too hard on the northern flank. Who knows …

  12. More gas/varor emission again from Fagradals volcano. Perhaps another round coming up?

    • Jay. Let’s hope for a dose of good clean Icelandic fun. Somehow watching people’s homes turning into rubble and going up in flames doesn’t quite compare.
      Fond memories of La Palma and its people…

    • Impressive! Is that from now?

      Then lava fountains are really intense now causing thermal convection

      This is really bad because the lava flows will start to move more relentlessly

  13. Do not know if it was posted here already, in that case, sorry, but quite a nice view from the lava flow via drone

    • It almost looks more like a blowtorch than a lava fountain. It appears like a jet of incandescent gas spraying some small amount of lava.

      • The lava itself mainly issues from the secondary fissures downslope, it would seem.

    • The speed of these small particles (not the tephra) must be incredible, maybe supersonic. It’s like a blowtorch scarring the air.

      On the other hand, the dogs have returned…. Ironically, the name Canarias accordingly to Plinian came from two big mastiffs gifted to the king of Mauritania, around 40 BC. (Can = perro = dog).

      • I thought so too. For a lower bound: If these particles (or the gas) make 200m in 1 sec, that would yield ~700 km/h. At least it is clear where the noise comes from.

    • Yes, a lot of gas is being released at the moment. In addition, the IGN measured up to 11500 tons of SO2 per day. Even Etna produces such quantities only during a paroxysm and only for a short time. When that much gas is emitted, there must be a lot of magma under the mountain too. I ask myself whether there will still be an effusive eruption with larger amounts of thin liquid lava after the end of this explosive phase?

    • I have clearly been spoilt by the excellent drone footage from Gutn Tag and other Icelandic volcano followers. In this La Palma eruption I have seen only one drone that followed the lava for even a km whereas in Iceland the drone videos have been extremely good. I hadn’t realised we were being so spoilt with the Icelandic footage, especially as many contibutors had travelled many miles to take these drone videos and post them on Youtube for us. So I would like to say a HUGE thank you to every Icelandic contributer to YouTube,

      • I was also very disgusted to see in one news report of the La Palma eruption that they had stolen drone video footage from Icelandic contributers and included it as being from La Palma. I only realised what they were doing as I saw how fluid the lava flow was and looked at the background to see it was footage from Iceland!

      • Reassess your expectations. In the communities on La Palma, this is a natural disaster of huge proportions where severe losses are going to be incurred. All Iceland need be concerned about at this juncture is an old farm, a highway crossing and some buried cables. As some here have observed, this is not a ‘tourist eruption’, nor are the videos intended for entertainment, nor is the level of sophistication the same. Albert observed that it brings back images of Vesuvius in 1944. If you know that event, then you understand its import and impact. Moreover, as observed elsewhere, Iceland has learned to live with its volcanoes and has harnessed its geological resources to its advantage. Not so here. Take what you can for your own edification and pray for this community. It may remind you of Plymouth on Montserrat when done.

        • Yes, this is the likely reason. Drones are perfect to view the lava for entertainment, but they are much less acceptable over disaster zones. Of course we do get videos of overrun houses which fall in the same category. We don’t want to deny what is happening and we are interested in how the lava moves, very different from expectations, and how the eruption progresses. But always knowing that people are losing their homes and possessions. I repeat something I wrote a very long time ago

          A new year alights on a changeable Earth
          We wait in the hope of a volcanic birth
          Rumours of unrest and expectant hearts
          The impatient patience of the watchful guards

          Solfatara still sheds its sulphuric smells
          Yellowstone quietly geyses its wells
          Mauna Loa inflates while hiding its threats
          Stromboli’s lava still spurts pirouettes

          Fissures erupting to make people follow
          Flocking to glimpse the jets from the hollow
          But when the flow wanes, away the crowds leap
          In quiet the Earth can return to its sleep

          The future lies hidden in rocks deep below
          Where magma is trying to make fractures grow
          Mantle plumes rising and plates pulled apart
          The Earth in its silence still playing its part

          In faraway places the sleep is disturbed
          where ground is inflating and mountains perturbed
          Shaking begins – the magma is rising
          The world like a phoenix awaits fire’s baptising

          Tremors foretell of the burnings to come
          Delights to the watchers but sufferings for some
          Their houses on fire and lands overrun
          The people are fleeing whilst others have fun

          A new year alights on a changeable Earth
          We hope and we fear a volcanic birth
          Rumours of unrest bring fright to our hearts
          What power the Earth on our lives can impart!

        • The vast majority of the houses that were destroyed by lava were built on or right next to existing lava flows. They should never have been allowed to be built in such a dangerous place in the first place. A similar but less dangerous thing is happening in the South of England, where houses are now being built on areas that were never built on before because they were know for historical flooding and yes, how surprising, they are being flooded. This Area of La Palma has had two eruptions in the same area in living memory. So why do they take the high ground and try to stop people from watching the eruption? Because it damages tourism and a lot of money is involved in tourism? As someone else noted, if it had been human lives at stake then I also would have been horrified but houses? They can be rebuilt and will yet again be rebuilt on top of these new lava flows. Sometimes I cannot understand humans desire to believe such things can never happen to them personally. I personally have had far greater loses than material possessions and would gladly have given up my home if it could have saved lives by doing so.

          • It’s been discussed here in the length of time it will take for the heat to dissipate from those flows. I doubt that we are going to see any real estate enterprise beginning on this new ground for a very long time. Yes, a reasonable thinker would act in accordance with your views. However as with the south east rift zone on Hawaii there was nothing to deter building a new land which appeared in the 1950s.

  14. So far, the new volcano doesn’t seem to have a name. What about suggestions?

    Since the eruption took place on the “Cabeza de Vaca”, which means head of the cow, my suggestion would be “Vaca Negra”, which means black cow.

    But maybe there is also a suitable name from the language of the indigenous people (Guanches) of the Canary Islands. Many names of mountains or landscapes still bear the names given to them by the former indigenous people. I’m curious what the volcano will be called one day.

    • If it were to create a significant cone, it would propose “Cumbre Nueva” … but it is highly unlikely: it would need a very long and more productive eruption (so far it expels more gases than pyroclasts).

    • The map is not very current. At the far left of the picuture you can see the 3-way intersection with the roundabout that the lava reached this morning . It is still pretty far from the lava front shown.

      • You are right, but Copernicus is said to be THE emergency response apparatus for European countries. I guess VC and the drones are the only things which are in real time???

  15. Just watched this video https://www.youtube.com/watch?v=x_kK3xlj8d4 from someone called Bushcraft Bear

    A resident on the island talking about what it’s like. It’s worth a watch to hear how loud the volcano is from 10km away upwind. He says the sound is quite scary at night, and hearing how loud it is, it must be! Even after hearing the sound on fagradalsfjall and the tvcanarias videos I hadn’t realised just how loud and incessant the noise is. The people on the west of the island can’t be getting much sleep on top of the stress.

    It was also interesting to hear him say how irritating the dust was yesterday and how the weather is not normal and has clouded over and got cooler and more humid. Local volcano impact it must be. Can’t imagine how bad the dust is going to be for all the people there, must be very uncomfortable if it gets thick and the winds aren’t strong enough to blow it out to sea.

    Bushcraft Bear says he’ll keep updating with videos when something happens.

  16. A scientific paper titled “La Palma island (Spain) geothermal system revealed by 3D magnetotelluric data inversion” https://www.nature.com/articles/s41598-020-75001-z has a very interesting graphic for figure 2. In particular (c) in fig 2 highlights the geothermal heat on the south half, west side of La Palma quite well. This paper was published almost a year ago.

  17. Can any of the experts please help out and explain this graph from IGN?

    It’s measuring the strength of something like tremor or signals, but I can’t work out what and can’t find an explanation.

    Thanks in advance!

    • This appears to be an RTSM graphic, which means “Real-time Seismic-Amplitude Measurement”. It is the intensity of the tremor since September 19th. You can see that the tremor was highest on September 21st, respectively.

  18. Did anybody mention that the current eruption seems to originate from an old cone? Is this recycling?

    On the geological map it is indicated that the crater is >20ka old (Pleistocene).

    • It is a bit further west actually, the main fountain, but a vent did open inside the old cone.

      I dont think it is correct to say it reactivated though, the old cone is just a part of the landscape. Same as if in 100 years we get an eruption inside the deep crater of Pu’u O’o it is not a resumption, just an eruption in the same place.

    • Btw there is an interesting observation one cam make: The two crushed houses, the restaurant and the green house, seem to slow the lava stream down. A fire fighter also pointed this out. I know this seems odd, but I guess we don’t know everything about the distribution of forces that act in a huge viscous mass.

    • Cooling it with water wont work!
      Lava haves a very very very low heat conductivity. You just chills the outer surface, the cold can never penetrate into the flows interior. ( Thats why lava flows can flow many kilometers, many tens of kilometers underwater in insulated submarine lava tubes )

      Heimaey is often saied to be cooled by water .. but the water only formed a strong crust on the lava… while hot inside. Had the lava flowed directly towards Heimeay the water cooling woud have not worked at all

      Water cooling may slow a flows advance by making a strong crust
      But for really fast flows .. it wont work at all

  19. Tony watching the la palma eruption today I saw this video claiming a new vent opened up further up, but is this from today or is it media blending images from the past days? Iam not sure

    • We discussed this above. The video is from the beginning of the eruption. People in the social media shared this 100000000 times, nobody cares about truth.

      • saw this in a news report, looks like nobody cares to fact check anything now…

      • This morning I went to my apple iphone to check up on things. Scores of news releases in English, nothing in Spanish, all canned for consumption, with misfacts thrown all over the place. Nothi ng live, despite many saying “live”. Mega-tsunami was mentioned more times than I could count. Finally I had to come over to VC to pick up the live links. I discovered that if you go to the local link like TV Canarias, all of a sudden the youtube video presentation changes and you can see all the real news you missed. I am a bit upset about this. I also did mail the Geographico Instituto Nacional to let them know of missing information on their webpages. Basically it looks all today is eye candy meant for a fast glance, and then on to the next visual thrill. As far as real science goes, forget it!

    • It’s obviously not today as the sky is blue on the video, but it’s not at all on the live streams because of all the ash. Twitter seems to have some amazing ability to stop brain cells from engaging!

  20. It looks like the crustal deformation is occurring between LP03 and LP04, closer to the LPO4 GPS station. The latest earthquake S EL PASO.ILP at 2021/09/22 20:58:40 is close to LP03 location. I am wondering if this deformation is permanent or not? See https://www.ign.es/web/ign/portal/vlc-gps then for a look at the quakes and deformation data.
    I am aware of the inSAR readings, but I am not putting 100% confidence in the 21-Sept-2021 06:40 am UTC reading for displacement.

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