A Reykjanes story

Mount Keilir, on the Reykjanes Peninsula

Iceland does it rather well. Over the 1100 years or so since the Viking settlement, it has erupted some 63 km3 of lava, the large majority of it basaltic. A similar volume of tephra was also produced. The East Volcanic Zone is the prime suspect for any eruption, and with good reason: it is responsible for 51 km3 of this lava. All four regular eruptors are here: Katla, Hekla, Grimsvotn and Bardarbunga. But this means that 12 km3 of lava is missing, or at least went elsewhere. Where is it?

Of the missing amount, 8 km3 is hiding in clear sight to the west of Langjökull, in the Western Volcanic Zone. It forms the Halmundarhraun lava field, and was erupted between 800 and 1000 AD, probably a little before Eldgja. A further 1 km3 is in the North Volcanic Zone; a region which is much better at tephra than lava.

That means we are still short of 3 km3 of lava, a not inconsiderable amount. It is enough to bury Reykjavik (a very spread-out city) under 10 meters of lava. And it is in fact found not far from Reykjavik. The missing lava is located on the Reykjanes Peninsula, in between Reykjavik and its airport, Keflavik. No other nation in the world has build its capital so close to so much young lava.

So why is this volcanic activity on Reykjanes Peninsula so little known? It turns out that this region goes for larger and occasional, rather than smaller and often. It has been a long time since the last event here. But things are stirring and after 8 centuries, this sleeping beauty may have met her prince. She seems to be waking up.

Iceland in faults

EÁ = Eyjafjörður Deep. TFZ = Tjörnes Fracture Zone. SISZ = South Iceland Seismic Zone. A = Arnarvatn fault zone. NVZ, EVZ, WVZ = Northern, Eastern and Western Volcanic Zones. H = Hofsjökull volcanic system. SH = South Iceland flank zone. GK = Grímsvötn–Kverkfjöll volcanic systems. RR = Reykjanes Ridge. ÖS = Öræfajökull–Snæfell flank zone. RPTZ = Reykjanes Peninsula trans-tensional zone. Source: Geology and structure of the Reykjanes volcanic system, Iceland: Kristján Sæmundsson et al., 2018, Journal of Volcanology and Geothermal Research.

Iceland is riddled with faults. In this map, black lines indicate volcanic zones, and red are non-volcanic faults. The blue lines indicate volcanic flank zones, with some minor rifting, where stratovolcanoes have developed. The black arrows show the spreading direction.

The main volcanic zones are pure spreading centres, excellent for generating magma. The red faults are transform faults: these can provide pathways for some magma to reach the surface but they do not generate magma themselves. The pink lines are combinations of transform and spreading faults, also called trans-tensional faults. They have both sideways (lateral) motion and spreading (extension).

The Reykjanes Peninsula contains the only transtensional fault found on land in Iceland. At the tip of the peninsula, the fault bends to join the Reykjanes Ridge, where it becomes a spreading centre. On the peninsula, it is a bit of both.

Comparing the map to the volcanic eruptions shows that the majority of Iceland’s (on-land) lava is generated by the two main spreading centres, the EVZ and the WVZ. The Reykjanes Peninsula is the only place where the eruptions occur in a fault with a transform component. There is still some spreading: the spreading rate here is about 8 mm/yr, compared to 20 mm/yr for the EVZ (it varies a bit along this fault). The Reykjanes Peninsula therefore has 30% of the spreading of the EVZ, but has only 6% of its lava production. Allowing for the fact that the Peninsula is only half as long as the EVZ, it produces 2-3 times less lava per kilometer per centimeter of spreading. This shows the effect of the mantle heat underneath the Vatnajokul which increases the magma production there. Reykjanes lacks such a pronounced hot spot. On the other hand, it is much closer to the actual MAR where the Atlantic Ocean forms its new crust. It may perhaps borrow some magma from there.

Reykjanes volcanicity

But look closer. The eruptions may belong to the Reykjanes Fault System, they don’t use this fault for their progression. On the EVZ, eruptions form long fissures along the spreading fault. But on the peninsula the volcanic activity runs at an angle to the fault. They form a series of NE-SW segments, while the Reykjanes Fault System runs E-W. In fact these segments are approximately along the main direction seen in the EVZ and in the Reykjanes Ridge. It is the direction of the spreading rift. Dikes develop much more easily in this direction, as the crust is already being pulled apart. Magma is a lazy substance, and it will always follow the path of least resistance.

On the peninsula, eruptions may begin on the Reykjanes fault, but when they spread they take their directions from the spreading, and ignore the transform component.

The easternmost segment, Hengill, is considered part of the WVZ. The next ones are Brennisteinsfjall and Krisuvik, and these are the most productive of the segments. Fragadalsfjall seems to be a new development. Svartsengi and Reykjanes make up the end of the peninsula. There is a further system off-shore, invisible below the waves.

The most famous eruption on the peninsula dates from 1226 and occurred on the Reykjanes system, or a few kilometers out to sea. It was part of a longer sequence of eruptions which left the tip of the peninsula a volcanic waste land. Around this time, Icelandic sagas mention ‘fires in the sea’ at the Reykjanes Peninsula for 1223 and again 1225-1227 (which may or may not have been one continuous eruption). Within this series there was one particularly violent eruption: after this explosion in 1226, the southwesterly wind spread 0.1 km3 of tephra across the area, with a thickness of almost 1 cm as far as Reykjavik. The tephra layer from this explosion is found across the peninsula and is the most pronounced layer here over the past 5000 years.The sagas mention that it caused ‘darkness in the middle of the day’. The winter of 1226/1227 was called a ‘sand winter’. This word is normally used for the year after an eruption, and indicates the effect of the volcanic ash rather than the ash fall itself. It causes mortality in the farm animals, and famine. Fluorine may be to blame, but there are other possibilities. Ash and tephra are unhealthy for cattle when digested with the gras they cover. Sulfur emissions may also have killed vegetation, leaving insufficient fodder to last the winter. Farming and volcanoes make for an uneasy partnership.

It has been suggested that the Karlinn rockstack comes from this eruption, but this stack seems a bit too close to the shore and the explosion probably occurred a bit further out. There is an underwater ridge some 50 meters deep which seems suitable.


The soil layers show that a few years before the 1226 eruption there had been an effusive eruption on land, which became explosive when it reached the sea. The 1226 ash fell on top of the lava sand from this earlier eruption. This was a double hit: the vegetation would not come back for a long time afterwards.

These were not isolated eruptions. The peninsula contains a number of lava flows which were erupted within a 400 year period, between about 940 and 1340. The series began in the east, in the Brennisteinsfjöll volcanic system, with a series of eruptions, a few decades apart and ending before 1200. After 1150 eruptions began further west, in Krisuvik, also lasting until about 1200. Now the Svartsengi and Reykjanes systems joined in with a series of eruptions, from 1211 to 1240. The 1226 eruption was part of this group. Then it all ended, and the area has remained quiet ever since.

This behaviour of progressive eruptions turned out to be typical. There had been a similar series of eruption 1000 years earlier – and the same another 1000 years before that, and again before that one. In this region, eruptions move from the east to the west over several hundred years, terminate, followed by 700 years of volcanic sleep before it restarts.

(Hengill is not part of this sequence. It erupts rather infrequently: the last time was 2000 years ago. Its eruptions are connected to the WVZ, not the Reykjanes Fault System.)

The sequence may have gone on ever since the ice melted, but the oldest series have not left a record. Their flows were overwritten by later lava. It seems that the earliest eruptions, shortly after the ice went, were larger than they are now. As the land rebounded from the ice age 14000 yars ago, it may have generated more magma. Large shields formed: the largest one covers over 20 km2. Over time, the eruptions became smaller. But they did not fade quietly into the volcanic night: The thickest tephra layer dates from 6100 BP, up to 1.5 meters thick.

Why this progressive, sequential pattern? That is guesswork. My personal guess is as follows. The volcanic systems have formed a series of echelon (parallel) faults, which are being pulled apart by the rifting component. Over 500 years the spread adds up to some 4 meters, meaning that each fault has to counter about 1 meter of movement. That seems to be the maximum stress here that can be accommodated. When the stress exceeds this, the easternmost of these faults snaps open. Several fissure eruptions follow. Now the faults give way one after another, with Reykjanes as the last one.

Towards the end of the series, eruptions can also happen beyond the end of the peninsula where the volcanic systems extend for some 15 kilometers beyond the land. It ends before Eldey: Eldey is part of another system, offset from the Reykjanes Peninsula volcanoes, with its own eruptions. Here the bend in the fault gives a larger spreading component.

The area around Grindavik showing the alignments of the volcanic system. Image from August 2019. Imagery © 2020 Planet Labs Inc.

Magma in motion

As the rift opens, magma begins to come up. This seems confined to a fairly narrow band, perhaps 4-5 kilometers wide. Initially, it appears that a sill forms, pushing up the land. Eventually a dike forms, going either upwards or sideways. Eruptions can happen along the segments, showing magma traveling sideways. But they tend to happen on land, and not too far from the Reykjanes fault. However, the dikes can continue for much further. They have been traced 50 km to the northeast, well beyond Reykjavik and even beyond Hvalfjordur. But the dikes do not come to surface beyond a few kilometers from the Reykjanes Fault System. If magma takes this route, it stays underground.

But even underground magma can have an effect on the surface. The peninsula has permeable rock, where sea water can get in. Once it hits the magma sills, even after 700 years, it gets heated and moves up. These are the geothermal centres: there are four on the peninsula, each located along a segment close to the fault. The Blue Lagoon is one of these, although it should be noted that it is completely artificial: the lake contains the waste water of the local geothermal plant. And the distant dikes still generate some geothermal heat as well.

Sweet dreams

We are now some 700 years into the years of quiet. Over the past decades there have been episodes of unrest, perhaps starting with an inflation event at Hengil in the 1990’s. There have been several earthquakes swarms on the peninsula. The current inflation shows that magma is now accumulating, something that had not been seen here before. Is this another step in the re-activation? Will it slow down and stop, as IMO considers most likely? Or will the magma prince find a weakness, wake the sleeping beauty and come to the surface? Or will a dike develop taking the magma southwest? Time will tell.

But in any case, these are only the initial stirrings. If history repeats itself, the real eruptions won’t begin here. It will be further east, south of Reykjavik, with several eruptions occuring decades apart. It will take two to three centuries before the tip of the peninsula erupts. But will history really be condemned to repeat itself? Predictability is not normally a strong point of volcanoes. They may still surprise us.

116 thoughts on “A Reykjanes story

  1. Thank you Albert! Good read.
    Thats 126km3 of materials in Iceland since settlement

    Iceland is one of the worlds most powerful magma sources and coud be the most powerful oceanic one.

    In my life alone Iceland have produced many cubic kilometers it have erupted 1996,1998,2000,2004, two eruptions 2010 and then we have 2011 and 2014.
    Thats the Icelandic eruptions during my lifetime

    • The whole holocene output is probaly 460 to 560 km3 of lava from Iceland alone!
      Since the last glacial ended

  2. Excellent Albert!

    One thought; If the progression of activity from east to west is due to spreading (what else could it be) then the first rifting in the eastern parts, wouldn’t the rifting relax the more westernly parts and rather delay more rifting?

    • Yes, and perhaps that is why the western parts erupts centuries after the east. Each segment takes up about 1 meter of the spreading, over a series of eruptions. They reach breaking point at a similar time, but the first one to go gives some respite to the others.

  3. Im so senile LoL! forgets everything
    Whats the threat of lava to Reykjavik?
    Whats the chance of lava invasion in the city?

    I guess its very small
    But There are pahoehoe flows thats flowed inside Reykjavik long ago.
    Brennsteinsfjöll is the potential threat to Reykjavik?

    • It is in the Krisuvik system but the flows don’t reach Reykjavik. I think that the last lava tor each the city was 6000 years ago but someone may want to correct me. Havnafjordur, south of Iceland, is the furthest the Krisuvik flows have reached.

  4. Looks like Krýsuvík system is the most hazardus to Reykjavik
    In your map here and in others it extends under Reykjavik.
    Indeed Hafnarfjörður area haves a lava flow from the Krýsuvík system.

  5. Great piece, really informative.

    There’s something which appears to be a typo here “But they did not fqde quietly into the volcanic night: “

  6. Iceland is defenetivly the worlds largest purely volcanic Island.
    Reykjanes Penninsula is 100 kilometers long from Hengill.
    Iceland itself is 516 km wide at widest.
    Icelands submarine lava plateau makes Iceland 780 kilometers wide.
    Its growing wider and wider, without splitting as long as the Hotspot is alive and fills the rifts.

    • Zooming out on the IMO page to view “north atlantic” shows a very wide spread shot gun pattern with peak at reykjanes. Thinking that only a very large and very deep sited intrusion could give that effect with a spear head up under the center of the current seismic activity?
      Note:I am an amateur only.

      • Yesterday it looked like this

        But now they have cleaned up many of the ghost quakes. These were happening because the swarm hardly gave IMO time to adjust their new seismic stations into the whole set-up.

  7. Many thanks Albert! Very intersting read!

    Q. That sequence in the Reykjanes, is it known to affect the activity in for example the EVZ?
    One could guess when the rift spreading at the RPTZ is active, rift in the EVZ and WVZ is slowing down so less volcanic activity there … But is it?

  8. Thank you! Just what was needed to set our current focus of magmatic interest in context.
    This really is a great website, for where else would you get such informative up-to-date interpretative volcanic science and history all of which in a style open to all? Nowhere of course!
    Bravo to Albert, Carl and all VC residents.

    Take care, now.

  9. Thank you, Albert. An informed and very easy to read explanation. I particularly like the “Iceland in Faults” diagram; that has escaped my trawling over the years and explains much very nicely.

  10. Excellent article, and a couple of comments:

    Fragadalsfjall: I used to drive sometimes my jeep there, as the area ois pretty remote. Unlike all other systems, no lava there seems to be recent or even Holocene. So its a volcanic system that has been mostly inactive in Holocene.

    Aklthough Krisuvik and Reykjanes systems have the largest lava fields, which formed around 13th century, Hengill is potentially productive system and is the beast. It has some large shields, probably dating from early Holocene and some of its pre-historic eruptions must have been a couple of km3 in size.

    As you go northwards into Langjokull, the eruptions there seemed to have been even more voluminous, in the range of 1-10km3, and Skjaldbreidur is one of the largest shield volcanoes in Iceland. So while inactive the entire west volcanic system can produce some pretty large lava eruptions. And this articles makes justice to that.

    The part of your article stating the sequence from the east to the west, over several millenia, is just brilliant, and a fact that I wasnt aware of, but I had that suspicion before. If that is so, the question is: what triggered the start of a sequence.

    I found it fascinating that the sequence started around 940. This was just around the time that Edlgja erupted, so something might have happened tectonically-wise, across Iceland, that triggered that.

    Also interesting is the fact that the very large eruption at Langjokull erupted around that time too.
    And the sequence had just started from Brennisteinfjoll, towards Krisuvik.

    Take a moment to think about this wider sequence.
    You might think this was just a coincidence of events across Iceland.

    However, in 1783 Laki erupted. Then in 1784, a sequence of large earthquakes happened in SISZ across South Iceland, and then a large rifting events, which nearly terminated as a fissure eruption, occurred in Hengill, in 1789. The whole area had large-scale rifting but no lava erupted.

    I wouldnt be surprised if a dead zone rifting event is all that takes to start a sequence of rifting in the West Volcanic region. Or perhaps these were just two coincidences.

    Finally, interesting enough, research seems to show that there is a correlation with a general lack of activity under Vatnajokull when Reykjanes peninsula is active. Perhaps rifting switches between the East and West volcanic zone, just like day and night, and perhaps its a large rifting event like Laki or Edlgja that changes that.

    • Irpsit, about your last remark, EVZ and WVZ could, I think is, affecting each others activity. The map in the article seems to affirm this. The drawn lines displaying EVZ and WVZ are declining/ increasing width northeast-southwest wise as they are supplementary. The line representing the Reykjanes volcanic transform zone RPTZ, isn’t included in the WVZ though, it is in the map as a thin line as an extension, but possibly meant as standing alone (sorry, can’t find the full article the map originally comes from).

      It may react as such in the way as the NVZ does, independent of EVZ plus WVZ.
      So activity in EVZ means less activity in WVZ. But is not included the RPTZ…

      Triggering is another issue ofcourse.

  11. Great information, thanks Albert. Food was my reason for visiting this area: the lobster bisque in a small cafe in Grindavik (Cafe Bryggjan) is awesome. This region seemed much more barren than much of Iceland. Lack of rain? Soil Chemistry? Type of lava?
    There are probably some pretty good deals for real estate in Grindavik now.

  12. The CSM graph for Grímsvötn has by my reckoning reached a point where (according to the two previous eruptions) we may have about 200-250 days(rough eyeball) before the next eruption, that is, if the graph starts rising at the same rate as it did for the two previously recorded eruptions, when they were at the same place in time.

    • We are planning to come back to Grimsvotn soon! And there is also the Wrangell post in the pipeline, for people who like rain. 2020 has been a bit of a volcanic rollercoaster so far.

    • Interestingly, the GPS trajectory of the GFUM station will in the same timeframe reach the same spot as it had right before the 2011 eruption (with the eurasian plate as reference). The up component will be off, but I suspect that if you remove the general uplift due to melting glaciers it too would be at a similar place as before the 2011 event.

      • It is far from any habitation so is not particularly dangerous, as volcanoes go. Not safe, of course.

      • Grimsvotn was largely responsible for the Laki eruption in 1784. So yes, it is dangerous when it goes big.

        • The question is more .. like
          Whats Grimsvotns largest eruptive capability? worst scenario?
          Can it do larger than Laki?

          The more I reads about it, the more
          I learns its a volcano of great size and power..

          Grimsvotn is talked about having resovair of perhaps more than 400 km3 of magma.
          Some nerds says its 800 km3 of magma that lurks deep below Grimsvotn!
          Is that true ?

          • I read somewhere (I don’t remember where) that Grimsvotns eruptive capability is somewhat smaller than Katlas. But this is more based on a comparison between the Eldgja eruption and the Laki eruption. Eldgja was bigger and was a Katla driven event.

          • I could refer you to our Eldgja series for a discussion on the ‘fires’. They are the most dangerous types of eruptions but are infrequent and at the moment it does not look like any Icelandic volcano is primed for one. I estimated that the largest Iceland can do is 30km3 effusive, which means Eldgja came close. For Grimsvotn we expect the next eruption to be explosive, and probably VEI 3.


          • Hi Jesper here Im Johans brother

            both Grimsvötn and Katla has/have very large magma supplys and is both capable of very large basaltic eruptions.

            Grimsvötn has the largest supply and is the most active of these two.
            But because its most active.. it does smaller and more frequent eruptions than Katla does.

            Grimsvötn is much more active than Katla and thats Probaly why eruptions are generaly smaller in Grimsvötn ”smaller and more frequent”

            But knowing Grimsvötn have the largest magma supply in entire Iceland… it Probaly is the volcano with the largest eruptive capability in Iceland.

            In Early holocene Grimsvötn did a seriers of absoutley enormous basaltic Plinian tephra eruptions.
            Sakursunarvatn Plinian basalt tephras is from 5 around 30 km3 basaltic Plinian events from Grimsvötn.
            Each event was like a 2011
            But 30 times larger than that!
            The total basalt tephras from These Grimsvötn eruptions is 150km3

            The largest holocene lava flow rift eruption in Grimsvötn is Probaly Lakis 15 km3 Thats covered parts of the Eldgja flows.

          • Have Grimsvötn now Re- charged the near 800 million cubic meters that was lost in 2011?

            The subglacial lake is also permanently higher in water levels after 2011
            Suggesting 1 km3 of lava was also rapidly emplaced on the deep lake floor

            Givning the total volume of near
            1, 7 km3 erupted 2011
            A camera drone sent to the lakefloor is needed to find the 2011 s rapidly emplaced lake floor lavas.

          • A 0,2 km3 yearly supply for Grimsvötn fits perfectly to resupply 2011 s 1,7 km3 in around 10 years.
            Looking at CSM and GFUM graph for Grímsvötn its refilled soon. But lots of magma also ends up in passive rifting lowering the instant supply.

            The extra 1 km3 was erupted as lake floor lavas during the 2011 eruption a fact that IMO have checked according to Carl in papers and information he found about 2011 event

  13. Taal still showed the hot spot today, but it is quite a bit smaller than it was four days ago. Things are cooling down. Not safe (stay well away from the island, I would suggest) but not as threatening as before.

  14. Another 3.3 quake this evening, Anyway, there is a Geothermal Powerplant pretty much right on top of this volcanic area. If an eruption would take place covering a large area with a new lava field its a high probability that the powerplant (and the blue lagoon) is doomed. Where are the other geothermal powerplants in Iceland (there is another one further out on Reykjanes), and how much of Iceland’s energy production comes from this plant?

    • The Svartsengi power plant has a faceplate capacity of about 75 MWe. That’s a bit more than 10% of the total geothermal power capacity for the country, or about 3% of the overall total (most of Iceland’s electricity is produced by hydropower plants).

      Of perhaps more significance is the roughly 150 MWth produced there – Svartsengi provides heat to substantially all the homes and businesses on the peninsula.

      [Comment rescued from the dungeons. Welcome! /Lugh]

      • So a disruption there won’t do much harm to the overall power-source on Iceland then, just a matter of heating issues which is of course a concern.

        Must have been some exiting (maybe too exiting) last two weeks for the population of Grindavík! There was some (significant?) activity and inflation at Krýsuvík some 5-10 years ago is i remember correctly that slowly waned out after a while. Far from as intense as the current one in Svartsengi, but how do the two compare to eachother?

        • You truly don’t want to be without heat here in the wintertime. 🙂

          There’s been quite bit of activity in the last couple of years, but volcanoes are like cats – they do what they want, when they want, and they know how to get your attention. Also, they’re surprisingly messy.

          Fun fact: in September 1977, during the Krafla fires event in NE Iceland, magma entered the reservoir feeding the country’s first geothermal power plant. One of the wells briefly erupted, spewing several cubic meters of scoria. Not only did the power plant remain operational (it’s still in use today) – the well that erupted was returned to service, too, and remained in use for another 25 years.

          • Oh i am familiar with the heat during wintertime, because its certainly not any warmer here (Norway) than Iceland! 😉

            Interesting fun fact though!

    • Hi Jesper, there’s a written English mistake that I’ve noticed you keep doing again and again, when you write “haves” it should be “has” pretty much every single time, unless you are talking about rich people.
      Just a friendly correction to help you improve your writing 🙂

  15. What is your “amateur” projection for this, guys? Do you think it’s like what the scientists say and that it will most likely not end with an eruption or do you think it’s going to erupt? 🙂 Do you see any signs?

    • It is undecided! The earthquakes at the moment remain at 5 km depth, and there is no indication that the magma is moving upward. So at the moment it is not heading for an eruption. But if the inflation and earthquakes continue, the chance of an eruption does increase with time. We recommend though to listen to the professionals. If something is coming, they are the ones who have all the data and knowledge, and have the responsibility to keep the locals safe.

    • “amateur” … hey, I qualify for that. 😀

      As I noted in the last comment chain, the alignment of the fissures from previous activity, and the current reviewed quake sets seem to fit the criteria of Reidel sheer patterns over a transform fault. Many of the features along SISZ including Hekla, follow this same symmetry. If these are in fact Reidel features, my interpretation is that magma does not have to have the enormous pressure needed to breach a path to the surface by cracking rock and forcing it’s way out. Even if it is under moderate pressure, if a path opens up to the surface due to tectonic forces, it will flow and erupt as long as the available pressure can push it that high.

      I am not a volcanologist and am far from being an expert, but I think Hekla operates under similar mechanics.

      Hengill? Not quite the same. It sits over a veritable triple junction so good luck in predicting how it operates. Triple junctions by their nature are seismically noisy regions. The Hreppar micro plate, North American Plate and the Eurasian plate meet there. Note: Hreppar is bounded by SISZ, WVZ, EVZ (includes the Dead Zone), MIB.

      And since the ginormous rock cracking pressures are not needed for magma to get out… it would be a relatively sedate eruption once the groundwater driven explosions subside. (If anything happens at all)

  16. As a general point, if your comment does not immediately appear, it has probably been put in the dungeon by our system and needs to be approved by one of the admins. That may take some time (hours, typically). Once approved, further comments should appear without delay.

  17. What are your thoughts on the eq activity just west of Torfajökull?
    It seems to have been going on for a while now.
    Also, my drumplot reading could do with assistance. Was there a bit of noise leading up to the 2,9, and does it mean anything?

  18. There appears to be some very light tremor on the GRV plots today, nothing very significant but it has not been there before, winds are light this morning so you can see it.

  19. Hey
    A Quick question.
    Is The Thorbjørn volcano extinct?
    The facebook page og “Blue Lagoon” is saying so and now I’m just all “hmmmm 🤔”

    • Thorbjorn would be the name of a hill, the corresponding volcano is Svartsengi which is active. It is a fissure swarm lacking a central volcano, I think, so it can erupt from fissures over a certain area.

  20. For anyone who wishes to follow the swarming taking at Michoacan-Guanajuato Volcanic Field this I think would be the best source:


    The swarm is quite intense, 11 earthquakes M 4.0-4.1 in the last 3 days, and seemingly hundreds above M3 for the same period. It follows a volcano-tectonic distribution (as opposed to mainshock-aftershock) so it is almost surely a magmatic intrusion.

    Paricutín cone falls within the swarm.

      • The link itself takes me to a page that includes a map (chrome browser, desktop computer)

    • Yes, the link takes you to a map, the area where the swarm is taking place is near the city of Uruapan (about 300 km west of Mexico City).

      There is also an option to search their catalogue: http://www2.ssn.unam.mx:8080/catalogo/

      The swarm started in January 5 and since then 2000 earthquakes are listed and almost all of them with a magnitude of more than M 3.4! From taking a brief look it seems that activity has been increasing.

      • One day a farmer saw a steaming hole in it’s field, 4 days later it had already grown to 150 meters… The eruption lasted from August 1945 to March 1952. Parícutin is – if I’m right – still the only volcano that could be studied from birth to end.

        Image from here: http://paricutin.umich.mx/19_Paricutin_SaberMasVolcanes.html


        A 4.1 and a 4.0 have now been registered and several earthquakes of almost 4.

        This could become interesting, we may see a volcano being born.

          • Unlike Parícutin, Surtsey is knee-deep in water. As a result, it wasn’t studied from birth to end as crucial early events such as the initial formation of the eruptive vent took place out of sight underwater. If we’d known it was going to happen we might still have had instruments and cameras/divers there observing the sea bottom, but we didn’t. Whereas a farmer actually witnessed the initial opening of Parícutin’s vent, and any near-future repeat is likely to be well-instrumented and camera-observed from the get-go since the approximate site of the vent will be guessable in advance from seismic data.

          • Talking about the moment when Paricutín was formed, this is the account of Paula Pulido who witnessed the event:

            “About 4 p. m., after talking to my husband, I heard a kind of loud whistle,
            like the noise of water falling on live coals or hot embers. This noise was completely distinct from the underground noise I had been hearing, and the trees swayed strongly and continuously. I was about 100 meters from the place where these things took place, when I saw, issuing from a crevice that had formed, a little cloud of gray and I smelled an odor like sulfur, and I noticed that some pines about 30 meters from the orifice began to burn. I called to my husband. Then the ground rose in the form of a confused cake above the open fissure and then disappeared, but I cannot say whether it blew out or fell back-I believe it swallowed itself. I was sure the earth was on fire and it would consume itself. From
            the fissure arose a gray column of smoke, without force, depositing a fine gray dust.”

            I think that the Mayotte eruption should also be considered a monogenetic volcano. Mayotte itself is a polygenetic shield volcano, or better said was, when it was still over the Comores hotspot, now the central volcano is extinct. The vent that has been feeding the eruption since 2018 is independent and has been observed to get magma directly from the mantle, its magma source is 30 km deep so it would be considered a nice example of a monogenetic volcano. Its life is still not over though, as it is still erupting.

          • Paricutin was the first monogenetic cone to be observed from birth to end.

            Surgery might be a new volcano system, not monogenetic. Not sure if there was a previous hill underwater prior to 1963.

            As a system it is a very young volcano. It might have been its first eruption.

            Hekla is also very young, born around 7000 BC.

        • There is also Waiowa,a remote maar in Papua Nueva Guinea that erupted in 1943. Coincidentally it is the same year Paricutín started to form.

          • Was Waiowa monitored from birth, though? New Guinea in 1943 had other concerns, notably the unwelcome presence of the Imperial Japanese Army. I believe that more recent fieldwork has shown that it’s part of a volcanic field, albeit the only vent to appear in historic times

    • Some of those quakes are comparatively deep… movement going on down there, bringing up fresh materials.

  21. TAAL VOLCANO BULLETIN 04 February 2020 8:00 A.M.

    Activity in the Main Crater in the past 24 hours has been characterized by weak emission of steam-laden plumes 50 to 500 meters tall that drifted southwest. Sulfur dioxide (SO2) emission was measured at an average of 231 tonnes/day on February 3, 2020. The Taal Volcano Network recorded two hundred twenty-three (223) volcanic earthquakes including eight (8) low-frequency events and one (1) harmonic tremor that lasted nearly three minutes long. These earthquakes signify magmatic activity beneath the Taal edifice that could lead to eruptive activity at the Main Crater.

    Alert Level 3 is maintained over Taal Volcano. DOST-PHIVOLCS reminds the public that sudden steam-driven and even weak phreatomagmatic explosions, volcanic earthquakes, ashfall, and lethal volcanic gas expulsions can still occur and threaten areas within Taal Volcano Island and nearby lakeshores. DOST-PHIVOLCS recommends that entry into the Taal Volcano Island as well as into areas over Taal Lake and communities west of the island within a seven (7) km radius from the Main Crater must be strictly prohibited. Local government units are advised to assess areas outside the seven-kilometer radius for damages and road accessibilities and to strengthen preparedness, contingency and communication measures in case of renewed unrest. People are also advised to observe precautions due to ground displacement across fissures, frequent ashfall and minor earthquakes. Communities beside active river channels particularly where ash from the main eruption phase has been thickly deposited should increase vigilance when there is heavy and prolonged rainfall since the ash can be washed away and form lahars along the channels. Civil aviation authorities must advise pilots to avoid flying close to the volcano as airborne ash and ballistic fragments from sudden explosions and wind-remobilized ash may pose hazards to aircraft. DOST-PHIVOLCS is closely monitoring Taal Volcano’s activity and any new significant development will be immediately communicated to all stakeholders.

  22. Since the field is monogenetic, we shouldn’t expect Parícutin to erupt again. Instead a new cone will form. The previous two formed about one and three centuries ago, respectively, so it wouldn’t be beyond the pale for the next to form soon. Based on the preceding two events we can expect the eruption to last for several years to a decade, be mostly strombolian-to-vulcanian, and attain a cumulative VEI of 3 to 4.

    I hope the farmland in the area is insured…

  23. Radar image from a few days ago shows the craters on the old lake floor. The bank in January may have created a crater of 200 meter across, in my quick estimation.

  24. A HUGE lava lake is apparently present in the “small” stratovolcano Mount Michael at Saunders Island.
    May that volcano one day be visited to check for glow and hike up to the lava lake rim.

    Saunders Island. is as far away from the south pole as south sweden is from the north pole…
    yet Saunders Island haves a polar climate.. the immense icesheet of antartica dominates the climate up to latitude 44 in some places of the sourthen ocean.
    Sourthen sourthen Hemisphere is cooled so much by the cold ocean and antartica

  25. What Grimsvötn looked like 2011 on IMO maps
    Knowing that the swarm extends Into the dead zone we can be pretty soure that Laki belongs to Grimsvötn system

    • Jesper, those are initial locations detected by the automatic system and are not very precise. A quick way to tell is to look for a black outline. if black outlines are missing around the dots it means the quake location is preliminary and unchecked. After manual review they are all centered over Grímsvötn.

      This map contains the final, manually verified, locations:


      • Tomas Andersson thank you
        Whats is the current 2020
        pressure and eruptive/ status/ capability of Grimsvötns upper magma chamber?
        Lots of melting in the caldera ice – shelf because of increased geothermal heat these days. Albert also says that 2011 s 1,7 km3 ( with lake floor lavas erupted added in ) is now refilled.
        The 2011 site today is almost open water ( But lots of ice floating )

        Grimsvötn is one of the largest basaltic volcanoes in the world and has on avarge the fastest and most ferocious basalt eruptions: at least on a human lifespann and scale.
        In my lifetime 1996,1998,2004 and 2011.

        If 2011 was ice free..
        then it woud be a hawaiian – style lava fountain 4000 meters tall emerging from the caldera wall. Like an extremely violent lava spray.
        The 2011 lake floor lavas was probaly erupted from sepparate fissures than the caldera wall eruption.

        Haves Grimsvötn higher magma influx These years? Maybe its the Iceland plume pulse responsible?

  26. Deep tremor in Hawaii from 07:42 to 08:09 below Pahala. One tremor quake located:

    M 2.1 – 15km SSE of Pahala, Hawaii – 41.3 km depth

    While tremor are at a background or low level it is interesting to note that brittle earthquake activity (ground cracking) in Pahala keeps going up even more. It has kept increasing since last summer.

  27. Two recent images of Taal (2 days ago) (source: Planet Team)

    I think that the white correspond to the active fumaroles. The center of the crater has gone quiet.

  28. Should I make a statement about my historically contested views on anthropogenic climate change or my disdain for general humanity to breathe life into this quiet comment section?

    • But… But… what’s wrong with general humanity?

      Surely you can’t really have a problem with your fellow man? 😉

      • Oh, I don’t hate people just for being people. I hate the masses for a slew of reasons. For good practice, I make sure not to let my personal views affect how I talk and interact with people. So I don’t hate you or anyone I interact with. I don’t let personal feelings about people decide how I feel about the people I see and hear from. But I am a true misanthrope so in a way yes. Yes I do.

        • Im a proud misanthrope too : )
          Cannot wait until Homo – Stupidus ges extinct!

          ( Homo Sapiens Stinkus Imbicillus )

          Comet Swift Tuttle will fix us soon ..
          dont worry 😊

          • I love impact events as much as the next guy but I’d prefer the geological extinction or a cosmic cause. AI might do it though.
            Are there any more misanthropes here? I want to know so we can all assemble! (Misanthropes assemble!) Let us rant about Homo Vainus.

          • If you’re a misanthrope then why would global warming bother you? You already believe people are doing what makes sense to someone with misanthropist point of view. People can’t see beyond the end of their nose in that case, Blaming, finger pointing, gaslighting, virtue signaling and assumed moral superiority without accepting personal responsibility is also a typical human behavior…. enough to make on a misanthrope

          • Humans are a very dangerous species for earths biosphere and ecosystems

            ( infact Almost no wilderness on land is left anymore with exception of deserts and the taiga and steppe )

            Too many humans using up earths landmasses and avaible space There causing habitat loss

            So its easy to intensely dislike
            homo sapiens:

            But I will make soure that I still have a tiny trust left in humans 👍

            If humans act now with reducing world population in long terms and reducing intense land use..
            it is still possible to save the biosphere and the little megafauna thats left

          • I am neither vegan nor vegetarian. But I do know that half our impact comes from cattle. If you want to reduce our impact, reducing the number of cattle is the fastest way of doing so. Reducing our population would also be helpful but of course takes much longer. The best way to do that is by improving education. Research has shown that the number of children depends on the level of education of the women (not the men!). Most of the current population increase is in Africa, especially in regions affected by wars 20 years ago. The schools closed, and world population projections went up by a billion people. Asia is showing how it can be done. Africa shows how not to it. We need education programs for women. And in view of the opposition by some men, I expect this will often have to be done remotely. Our on-line world may finally make it possible.

          • The worlds population must be reduced
            A human live for 80 years so simply billions.. just dont have to get kids this centruy. ( it can be done with information and reducing family growth in friendly and democratic ways )
            Must be done to save the biosphere and avaible resources for everyone.
            Im not a fan of our dangerous civilization.

            But at the same time, Im politicaly green enviromental.

            If 8 billion persons lived like norweigans, we woud need 8 whole earths of natural resources I think.

            Many experts says when world living standard increases
            the world population will slowly decline in numbers, a positive news too.
            But we humans needs a new kind of society and think ( economy thats dont drain our planet dry of resources )

            The world is slowly on the correct path with rise of green technology and and increasing public knowledge of humans impact on the planet.

          • Todays biodiversity is nothing compared just before agiculture and specialy just before the megafaunal mass extinction
            ( last time Earth had healthy fauna was during Eemian 140 000 years ago )

            Europe and America and Asia should be full of Elephants, lions, mammoths, giant deer, giant bears, cave lions, cave hyenas, cave bears, bison, hippos, sloths, cheetahs, leopards, ancient cattle, and predatory flightless birds.
            The Elephant diversity was specialy large just before sapiens came around.

            Thats the natural fauna of Europe and America and Northen Hemisphere.

            Im an enviromentalist and specialy intrested when the current modern fauna was at its most spectacular in Early Pleistocene.

          • Dellenite, My issues with anthropogenic climate change lie in the fact that there so much overhype with some of these issues. https://www.space.com/venus-runaway-greenhouse-effect-earth-next.html
            That is not to say the science isn’t solid but i believe when fame and money are to be made, a skeptical position should be taken when looking someone’s agenda.
            This is made worse that somehow other enviromental issues are ignored, such as overfishing, pesticides, plastic, and slew of other issues.
            I know that some of greatest advocates for action against climate change have a political agenda (Not conspiracy!) My comment concerning that got deleted on the chance it could start a flame war.

            The masses have always been selfish, around 89,000 children have starved to death due to a war and not natural causes but my fellow Americans still think that some celebrities minor family debacles is somehow more pressing then the death of innocent children.

          • If you face disaster from several things, you have to deal with all of them. Ignoring one to deal with the other still spells disaster. (d-i-s-a-s-t-e-r) The global heating predicted by the IPCC is conservative. That is 3C this century, with 70 cm of sea level rise. We are currently on a 5C track but the assumption is that people are coming to their senses. But when the US takes security measures, they plan for the worst. For climate, they hope for the best. It is a notable difference.

        • I will like to write an article on how I have viewed anthropogenic climate change maybe next month and I will list all of my grievances with it then. Something else has caught my eye at the moment
          If the entire world would use renewable energy that would still hurt the enviroment and the idea that somehow all of this is going to change through some taxes and restrictions on the common people’s resources is going to fix global warming is almost comical but for some reason that is the exactly the type of action is what alot of media and people are pushing for.

  29. https://www.instagram.com/p/B8RbfUeCQZ7/

    Nyiragongo overflowing again Into the caldera floor
    ( fresh dark overflows image: last week )
    The lava lake have never been this high since 1977
    The higher the magma column builds itself by overflow layers stacking around it, the higher the lava lake gets the pressure in the magma column gets.
    Higher pressure increases the risk for catastrophic intrusion and draining of the lake like like 1977 and 2002
    Nyiragongo is beyond creepy when it goes flank eruption

    We will see how long lived and high This lava lake will get .. But it have been there for 20 years now

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