Time for komatiite

The Barberton geotrail

People mellow with age. At least, most of us do. The emotions of youth become less all-important and less demanding of our attention. Young people feel that every perceived slight needs addressing. The heat goes to the head and mistakes are made. The Earth, too, went through that phase, before it settled down in middle-age continentality. Volcanoes were everywhere and the lava they produced was hot. It was a restless time. It took the Earth a billion years to grow out of it.

The young, hot-headed earth was almost entirely a water planet. We are talking 4 billion years ago and the time of the late heavy bombardment had just ended. The first continental slivers were forming. The oldest of these that survives is at Amitsoq, south-east Greenland, a combination of volcanic and sedimentary rock. Plate tectonics was beginning although still in its infancy: full blown plates with their subductions would not exist until another billion years. But mantle plumes existed, probably more plentiful and faster than nowadays. These threw up volcanic plateaus and islands, and these became the cores of the new continents.

The best recorded of the origin stories of the continents comes from the Southern African craton. This was once the heart of Gondwana. But the region was much older than this. The oldest rock here is a staggering 3.6 billion years. It takes us back into a different era, called the Archean, a period lasting until 2.5Gyr ago. The Earth was a different planet. The atmosphere was not conducive to life, with high CO2, probably mixed with methane to give a photochemical haze in the air. But the ocean already existed. The oceanic crust was divided into numerous microplates, where everything was more active than now. The interior was hotter. There were no continents yet but there were plenty of oceanic islands.

Building a continent

The location of the oldest rocks of the South African craton are in Barberton. They are called the Barberton greenstone and they tell a story about how the continents formed.

The rocks form a belt stretching from northeast to southwest, roughly 100 by 60 km with rocks covering an age range of 500 million years. The region is at the border of Swaziland, just south of the famous Kruger park. The southern parts of the Kruger park are dense with wildlife and tourists. The river is full of hippos and crocodiles and the wooded area hides the elephants well. They have right of way, even if suddenly appearing from the bush, and they know it. They happily chase the drivers to let them know who is boss. The real Kruger is not here: that is much further north where the land gets wilder and the animals more dispersed. But if you want to quickly get your African safari in, the southern Kruger is hard to beat. The birdlife is also superb. Sometimes the animals get out of the park, and you may suddenly find a hippo in your pond. Nothing to do but call the park service and ask whether they do collect.

The Kruger park is rugged, with lots of granite ‘kopjes’ (small peaks). The landscape looks ancient. But it is nothing on the Barberton area where the rock are many times older. Not much has survived, of courses. The originally horizontal layers have turned on edge in timeless upheavals. This is why the belt is narrow. The whole area is embedded in ancient graniodorite which has survived better – partly because it was underground. It is all part of the story.

The Barberton mountains are a green land: in the wet season it is covered in bush and some forest. It is an ancient greenstone, but that does not refer to the vegetation. The ‘green’ in the greenstone comes from chlorite, and it makes rock rather unpalatable to vegetation. The chlorite is a later metamorphic addition to the rocks, but it shows its origin as oceanic crust.

The original rock consists of three groups, called Onverwacht, Fig Tree, and Moodies. Onverwacht is the oldest of the three. It is mostly volcanic. The rocks of the Onverwacht group show how volcanic rocks erupted onto an ocean floor. Just like in modern oceans, the water cools the surface of the lava and the pressure prohibits any explosive activity. The result is pillow lavas. Indeed, the Onverwacht group shows plenty of these pillows in the region. There is little doubt how this land began, deep under water.

The most common origin of pillow lavas is a mid-oceanic spreading centre. That has also been suggested for the Barberton rocks. But it has been questioned. The eruptions began 3.54 Gyr ago and lasted for 250 million years. That seems too long for a spreading centre. The layers also are extensive and not faulted. The suggestion is that this was a volcanic plateau or submarine shield volcano. It is not known whether plate tectonics in its modern form, with spreading centres and subduction zones, had already developed on Earth. It may have been an environment more like Venus, with areas of volcanic activity and deeper basins without, but without larger scale motion from one such area to another. The origin of plate tectonics is still debated.

In the modern world, pillow lavas produce basalt. But although the Onverwacht group has a minor basaltic component, the majority were a different, much hotter type of lava. This type was first identified in the Barberton belt, along the southern part where the river Komati flows. It thus was given the name komatiite. They don’t make it any more. Nowadays, oceanic basalt is melted in shallow magma reservoirs at temperatures of at most 1300 C. The komatiite was formed several hundred degrees hotter, up to 1650 C. They came from a mantle that was notably hotter than nowadays.

The eruptions were not continuous: they were interrupted by epochs when thin layers of sediments collected, composed of iron-rich and silica-rich mud and volcanic tuffs. After the pillow lavas stopped forming, the sedimentation kept forming, now including carbonate layers which buried the lavas. The sedimentary layer is called the ‘middle marker’ and is a widespread part of the Onverwacht group. The carbonate shows that the ocean was much like that of today, with abundant calcium carbonates. The most notable is a dacitic layer, 2 km thick, dated at 3.45 Gyr ago. This has been interpreted as the subsiding volcanic peak, in fairly shallow water.

Fine-grained mafic ash, Onverwacht Group showing cross-bedding stratification.

Now a second pile of volcanic rocks formed, but with a composition of basalt and dacite. This is the upper Onverwacht group which formed around 3.42 Gyr ago and there are similarities with modern-day island arcs. The magma did not come from as hot a chamber as the earlier komatiites. The dacite suggests that the magma chambers had time to cool and differentiate. It has been suggested that the newly formed oceanic crust was subjected to some subduction, partly melted, and percolated back into the crust.

Now things quieted down for a while, until the Fig Tree group formed between 3.26 and 3.23 Gyr ago. It is a volcaniclastic sedimentary sequence that is capped by felsic volcanic rocks that formed in deep- to shallow-water to alluvial environments. Some of the deposits show evidence for turbidites: underwater landslides. In these slides, the coarse material (sand) reaches farthest and mud the least: mud therefore forms the upper slope. The mud stones are quite black from the amount of graphite. This suggests that the volcanic islands were bounded by a trench into which the slides went down.

The Moodies Group was deposited next, between 3.23 Gyr, and 3.11 Gyr ago. It consists of shallow-marine to fluvial sandstone and conglomerate with minor shale and banded iron-formation. It shows some banding that is typical of tidal bays, where even the neap-spring tide cycle can be seen. Counting the layers shows that there were only 18 days in a tidal month, a combination of the Earth spinning faster and the Moon being closer than nowadays.

Silicified cross-bedded and wave-rippled sandstone overlain by chert-slab conglomerate; Buck Reef Chert , central Barberton Mountain Land.

What happened? The island arc and trench suggest that plate tectonics was beginning to behave more like the modern Earth. The partial melt had formed a graniodorite (felsic) which had been emplaced in the oceanic crust. This reduced the density of the crust, thickened it, and caused the area to rise. When the oceanic floor began to subduct, this region was too buoyant for that. This lower density material formed the core of the island and morphed it into young continental crust. The lithosphere thickened and formed the 100-km deep keels of the modern continents. The Barberton area was not a single terrane: it was several distinct regions which formed in different places and only came together during the last phase of the Moodie group.

This process went on not just in the Barberton area. Similar events took place elsewhere in the world. The Pilbara area is an example, with the same age as the area here. The next phase came when series of these new island arcs began to amalgamate. This formed the core of the new cratons. The earlier granite was remelted, and now formed large emplacements of over 60 kilometers in size. The process would continue for another 500 million years. By the end, the world was full of microcontinents. The first continental collisions occurred. Mountain building began. 2.5 Gyr ago, the Archaean ended and the modern world took shape.

Microbial laminations interspersed with sandstone and overlying conglomerate of a fluvial-supratidal sandplain, exposed in the Moodies Group of the Saddleback Syncline, central Barberton Greenstone Belt. Angular green clast is composed of altered ultramafic rock. This and previous photos: 35th International geological congress, 2016, Cape Town

Impact

There was another event which left its scars. At 3.26 Gyr ago, the Barberton area shows a layer of spherules. The spherules are the size of sand grains, and formed from condensation of rock vapour in the atmosphere. Effectively, these were liquid rock drops which formed in the atmosphere. It rained rock. There are four such layers in the Barberton greenstone, but this layer (number 2) stands out, at the border between the Onverwacht and Fig Tree groups. The layer has a thickness between 20 cm and 3 meters, of which between 10% and 50% consists of the spherules. It is present in the southern area of Barberton. The same layer is seen in the Pilbara area. It contains chromium indicative of an extraterrestrial origin. This was a meteorite impact, from a carbonaceous chondrite. And not just any impact.

Spherules from layer S2. Source: Lowe et al. ASTROBIOLOGY Volume 3, Number 1, 2003

Based on the thickness of the layer, the impactor has been estimated as between 37 and 55 km in diameter. This is considerably larger than then the KT event. The impact caused dikes to form in the Onverwacht group. Some of the spherules found their way into these dikes, suggesting they were still open when the rock rain arrived. Gradation of the spherules suggests passing tsunami waves. The area was still deep under water, but this did not protect against currents caused by the tsunamis, or the earthquakes. The moment of the earthquakes has been estimated at a minimum of M10.8. A crater of some 500 km across may have formed. However, this would have been on Archean oceanic crust of which little survives, thousands of kilometers away from the Barberton rocks.

Credit: American Geophysical Union

There was a second impact of similar size 30 million years later. These are likely the two largest impacts the Earth has suffered over the past 3.5 billion years ago. Were they related? That seems plausible. Perhaps a large asteroid had broken in two following a collision, and both fragments ended up with orbits with intersected the Earth. A game of russian roulette followed which only had losers.

One more thing is worth pointing out. The S2 layer is exactly at the change-over between the Onverwacht and Fig Tree group. In fact, so is the S3 layer, as the change happened a little later in the north of Barberton where the S3 layer is seen. The Fig Tree group is one of felsic volcanisms, and the onset of internal melt which formed continental crust. Perhaps these impact had a role in this. They formed large cracks where magma chambers could collect, may even have induced melt themselves, and ended the epoch of komatiite. Was this a worldwide change? It probably would have happened over time any way, but these massive impacts may have accelerated the change.

Komatiite

But what is komatiite, and what was different about the Earth to make it form?

Komatiite is an ultramafic magma. ‘Mafic’ stands for a magma that is rich in magnesium and iron. Basalt does this: it is a property of mantle material, and mafic magma thus indicates that there is a conduit to the mantle. The mantle is not normally melted, so heat needs adding. That can be done either in a spreading centre (where mantle material can upwell from deep because of a lack of pressure above), or it can through heat from a hot spot. The hot spot can be shallow (most are) or it can be a proper mantle plume. The lack of silica makes the magma to be of low viscosity: it flows easily, and over long distances. It is also dense, and that makes it harder to erupt over the less dense continental crust without some significant heat input.

Ultramafic is even closer to the composition of the mantle, and has very low silicate content. In the modern world, this happens when magma chambers collect olivine from the mantle and slowly become more and more mafic. The result is picrite basalt, and this can erupt in places like Hawai’i. But in the early Earth, the olivine from the mantle could erupt directly and this is komatiite. It is silicate and aluminium poor and has a very high melting temperature. Its viscosity approaches that of water, so it flowed every more easily than basalt. But there haven’t been any significant komatiite eruptions since 3 billion years. The aluminium is not always the same: some komatiites are depleted in aluminium, but others are not. The undepleted ones are older.

Barberton komatiite. Source: wikipedia

The melting temperature of komatiite depends on its precise composition, and it appears those changed over the archaean. For a MgO fraction of 30% (typical for the early archaean) and chromite content over 1500 ppm, the melting temperature is around 1600C. The melt happens at 400 km depth, at a mantle temperature of 2000 C. This is believed to be appropriate for the Al-rich komatiites of Barberton, and those elsewhere in the world at that time. The mantle was hotter than it is now, due to higher level of radioactives, but not this hot. So where did the komatiites come from? The temperatures of a few hundred degrees above the normal mantle suggests the presence of mantle plumes. The komatiites are believed to have formed in the tails of superplumes. This puts the evidence for the extensive pillow lava under new light. These regions may have been the ancient, subsea equivalents of modern flood basalts.

Mantle temperatures

The hotter mantle would have had lower viscosity than the modern mantle, making plumes easier to form and faster to rise. But as the mantle cooled, things changed. The komatiites show lower MgO, less Al and Cr. They would have melted at lower temperatures, 1400C, and lower depth of 150-200 km. By the end of the archaean, 2.5 Gyr ago, conditions for komatiites were only found in few places and the fraction of such lavas decreased dramatically. The youngest komatiites erupted 100 million years ago on Gorgona island. But these are lower MgO, and the melting temperature was much lower than hat of the pure komatiites of the Archaean. They are part of our new, mature world. The hotheaded days of the Earth are well and truly over. All that is left is a memory of greenstone belt. Barberton is the graffiti of our youth.

Albert, February 2019

Protea in the late Barberton winter

136 thoughts on “Time for komatiite

  1. Hawaii is hot enough to potentially erupt komatiite, if magma ascended quickly from depth into kilauea it likely would be erupting at a temperature high enough to keep olivine as a liquid in the magma which would most likely classify it as a komatiite or something similar as opposed to normal basalt. The plume head under the big islands is over 1500 C and a few hundred degrees hotter than the average mantle temperature.

    1959 was probably the last time an eruption of this sort happened, its lava was mostly basalt but some of the later stages were unusual for kilaueas eruptions and included a lot of olivine and the lava was very hot probably over 1300 C on eruption.
    A similar high temperature was observed in later parts of 1960 (same magma as 1959 most likely), in 1969 from mauma ulu, 1983-86 several times at pu’u o’o, and especially last year after fissure 8 took off, fissure 8 lava was hot enough to erode the existing rock into a wide open hole which is why it never had a high fountain (no confining narrow vent). temperatures of 1250 C were also recorded in the overlook crater lava lake. Hawaii is most likely the biggest mantle plume on earth today, and probably the only one which actually has a solid connection to the earths core, making it more like the ancient archean plumes.

    • Overlook crater was not 1250 C
      It was something like 1198 C to 1220 C
      For Kilauea Overlook

      Fissure 8 in later phase was 1188 C to 1210 C

      Puu Oo was around 1150 C as it mixed with cooler ERZ magmas.

      Kilauea Iki was as you say around 1300 C as some fountains where near white hot

      • It seems unlikely that pu’u o’o lava would be that much cooler than the summit magma, maybe at the start in 1983 but by the time it became a main vent I think basically all of the magma between the chamber and the vent would be new, probably well over 0.5 km3 of lava was erupted during the pu’u o’o high fountains which would have definitely remixed all the magma involved in the conduit. Having a 100 C temperature gradient isnt even expected in lava tubes that long let alone deep conduits between 3 and 7 km underground, it likely took magma only 1-2 days or less to go between the summit area and pu’u o’o so the temperature is likely pretty much the same.
        The magma erupting at the summit didnt directly go to pu’u o’o either both were separate but fed ultimately from the storage areas under the summit, pu’u o’o and the rest of the east rift from deeper down and overlook crater from the upper system that goes to the SWRZ. Currently only the ERZ is still active the main part of the SWRZ is probably going to be functionally extinct until the caldera fills again and hosts a large volume lava lake and that will probably take decades or longer. It is fortunate no one lives on the SWRZ because eruptions there can be like eruptions on nyiragongo, sudden lava lake draining events which would be scary to be anywhere downslope from.

        • It takes much more than 1-2 days. The magma erupted has arrived to a near-surface reservoir by rising from the rift zone 2-6 km I imagine is a safe bet. In the rift zone the pit craters show that there are areas where magma can be stored, mostly in the UERZ. Even if the conduit was a perfect narrow tube it would still take a lot of time to make all the journey from the summit area to the MERZ. The DI events show that pressure changes in the summit extend into the MERZ almost instantly but the transfer of magma takes much more, I imagine days to years depending on the eruption rate. Years for Puu oo. It is strange why during the eruption in may the summit response to the collapse at Pu u oo took so long.

          • I dont see how it would take years to flow through the east rift between the summit and pu’u o’o, the best guess on how fast it moves is maybe a week, in 1960 it took about 2 weeks for the very hot kilauea iki lava to appear, and that is roughly twice as far from the summit as pu’u o’o. Last year if you ignore the initial small eruptions and take only the flows erupted after May 18 to be the real stuff, then it took about 2 weeks for summit lava to erupt at fissure 8, about the same time as in 1960. The lava erupting in fissure 8 was not stored rift lava it was almost entirely deep sourced very primitive lava from the lower half of the summit storage complex that had never been close to the surface before, so it likely takes around 2 weeks to flow the entire length of the east rift. Interestingly this is about the length of time between the last fountain from kilauea iki and the start of the eruption at kapoho so it is probable that those two eruptions should be counted as one continuous event.
            Pu’u o’o was erupting at about 10 m3/s on average based on my rough volume calculations which is a bit over 0.2 km3/year so pu’u o’o was erupting basically in equilibrium with the deep source until 2015 and likely none of the main magma system in kilauea is more than 30 years old.

          • I said it would depend on the rate. Fissure 8 was erupting at ~100 m³/s, a similar rate could be expected for the flow within the rift zone. At a rate of 23 m³/s the 1977 eruption wasn’t able to draw out any magma from the summit to the surface in 18 days. Since then the conduit through the UERZ and MERZ has been most likely enlarged by continuous use during the Pu’u’o’o and Leilani eruptions. Pu’u’o’o had very low production rates which would mean magma moved very slowly between the summit and the vent.

          • I think 1977 would be a bad example to go off because kilauea was still recovering from the 1975 quake and the 1977 eruption might have been triggered passively by south flank movement. The magma in that eruption is thought to have come from an intrusion in 1955 that preceded the second phase of that eruption. When the flank moved a bit in 1977 the summit drained into that space and the stored magma escaped due to gas pressure. During some of the high fountains at pu’u o’o the lava became primitive and unevolved within 3 days, and the same at mauna ulu in about 1 day, given that mauna ulu is about half the dustance between the summit and pu’u o’o this rate of about 10 km/day is probably the average movement. In both eruptions the high fountain stage was not faster than the slow effusion it was just not continuous so when eruptions did happen they were fast.

          • By primitive you mean rich in olivine? That olivine would be more likely to come from deep rift storage, in historic times the summit has practically never erupted olivine phenocryst rich magma, 1959 being the only exception I know. Magma can be enriched in mafic crystals through differentiation, as you know, and it is how modern ultramafic magmas are tipically generated as Albert explained.

            The 1977 eruption was preceded by inflation at Heiheiahulu so it wasn’t passive. The magma erupted was clearly of ERZ origin which means that at the rate the eruption was going and its duration magma from the summit abandoned the reservoir but never got to the eruption site and was left stranded at some point in the way, there is a permanent magma body (dikes, conduits or magma chambers) through a large portion of the rift zone and is where the lava erupted is directly drawn from, only once the eruption goes on for a long enough time and enough intensity might it start erupting melt from the summit.

          • Still, 1977 happened after a major disturbance to the east rift, much more than last year, so it likely took longer than normal and with more places for the magma to get stuck on the way. The inflation, both then and now, could be due to hydraulic connection through a continuous system with the lower part pressurised but the summit still deflated right now, which is also notable as it means such a system also existed before pu’u o’o formed.
            I think after 30 years of continuous effusion and magma transport that the conduit to pu’u o’o would have ended up being pretty efficient and it most likely didnt do any sort of random detours through magma chambers it wasnt originally connected to when it formed. Maybe the best number is the 18 day pause after the kamoamoa eruption in 2011, so far I have said a few different numbers ranging from 3 days to 3 weeks, but nothing getting even close to years, if it took years then the rift filling would prevent any sort of activity at all after a big quake for a very long time afterwards and that isn’t what we observe now or evidently in 1977. This did happen in 1868 but that was because of much lower supply rate while most of the hotspot was feeding to mauna loa.

    • But you are correct too
      If Kilaueas rise magmas very quickly it will emerge at 1540 C and pretty much flow like komatites

  2. As @Turtlebirdman says Hawaii may be able to erupt some gorgona komatites.

    Kilauea is really really hot
    And 50 km down its maybe 1538 C
    As hot as Hawaiis hotspot is
    These rocks are likley near completely molten
    Most of Big Islands interior is molten.
    The hotspot have made one huge partial melting pool at over 1500 C that may contain as much as many many tens of km3 magma thats 80 km below the island
    This is the pure melt pool that feeds Kilauea and Mauna Loa
    Kilaueas halemaumau conduit is directly connected with it siphones magma from 70 km below thats may be as hot as 1550 C

    The hotspot rises in the mantle and decompress
    And plume head ends up with being molten
    Hawaii haves a real plume head as the hawaiian swell suggest not just a plume stem like some other hotspots are.
    How much melt the hawaiian hotspot contains is unknown but its likey many many 100 s of km3 of materials below the seafloor in sourthen part of the island chain.
    And this deep stuff is so hot it can almost melt raw iron

    • There are some pretty hot magmas on earth. They can even produce a modern form of komatiite, but with lower temperatures than the archaean komatiite. The melt temperature is reduced by having a lower fraction of MgO (20% rather than 30%), depleted chromium, and importantly added water. The effect is that the melt may form at 1300C. That is still hundreds of degrees cooler than the Barberton komatiite: it is not quite the same stuff! What I find amazing is how low the viscosity was, similar to that of water. The old komatiite would have have come down at top speed, and very thin layers. On the other hand the density is very high which means that it could not easily erupt at any altitude. It would also need to rise very fast from the deep chambers, otherwise it adds crustal melts and cools on the way. But that is hard when it is such dense stuff. The ancient komatiite was mainly an oceanic lava.

      • Albert that woud be Hawaii that erupts it if it rises very quickly

        A Komatite eruption looks like flowing liquid slag

      • The most likley to appear when Kilauea reaches here peak shield stage boost
        And magmas rise fastest from the 1530 C plume source

  3. Potential Swift Tuttle impact will be very similar to the large asteroid in the Article
    Swift Tuttle also goes ridicusloy fast adding more energy

  4. Maybe one day even basalt will stop erupting? In other volcano news: absolutely nothing apparently- very quiet at the moment!

    • Possible. As the mantle cools, the melt under the mid-oceanic ridges will become more shallow and less volume. Subduction will still continue though

  5. Komatite eruptions resembles eruptions of liquid iron or liquid iron slag…
    These prehistoric lava flows where white hot at 1600 C
    Glowing intensely and pouring like water.
    Flows where extremely thin and narrow and filled small spaces and formed small channel systems at low eruptive rates.
    And large and sheetlike floodlike when eruptive rates where high poured like a river in flood.
    A Komatite flow where completely white hot with a orange yellow glowing crust or scum floating on the quickly moving lava stream.. unlike anything we haves today. Komatite pahoehoe must have been much less than a centimeter thick and dark and almost steelish and very dense when its erupted at low eruptive rates

  6. Been busy making this, a map of all the individual fissures on kilauea since 1790. Vents within the summit caldera fault I have coded in blue while vents outside the caldera are red.

    The locations of mauna ulu and pu’u o’o are also noted, because they formed within an almost solid line of fissures that I think is probably marking the location of the existing magma conduit, beyond pu’u o’o it spreads out, the next series of eruptions will probably be in this area and a long duration eruption will likely follow after some time, probably below the o in pu’u o’o, in the area of the 1977 eruption.

    • I know you understand the system well and I’ll be wrong! But it looks almost like the caldera part is on a kind of junction, or twist. I’d not noticed that before. Good map.

    • No you are actually pretty correct, I’m sure you have seen all the discussions but basically kilauea appears to be in the process of major remodeling. Up until only a few hundred years ago the main summit center was even further north than it is now with the main vent being next to HVO, and called the observatory vent. This is what became the original caldera that has been modified since then, and even comparing 1840 to now the main activity is much further south and with the shallow system of halemaumau now gone I expect activity to migrate again, the next eruptions might happen from the south caldera ring fault, or even within parts of the volcano that have never erupted before like the koae faults that are in the blank area below the summit.
      The east rift also most likely does not connect at shallow (~1 km) depth to the current summit like previously thought, it appears to be fed from the more general area deeper down (7-3 km) starting at the area near mauna ulu, when the volcano deflated in May last year the bit between mauna ulu and keanakako’i didn’t deflate nearly as much as the caldera or main part of the rift did and took much longer to show, so there is no shallow magma there.
      Last years eruption was likely so big because the quake opened up enough and at a sufficient depth that magma was able to drain out at the base of the east rift, making todays east rift now a lot deeper than this time last year which might be significant down the road. The eruption before fissure 8 started was pretty typical of a LERZ eruption that was beginning to enter its final stage, but then fissure 8 stepped into an entirely different league that was almost like an entirely different eruption.

      If I was to guess, in a few hundred years the summit will be completely south of where it is now, making a smooth connection to the east rift, which might result in eruption styles more similar to mauna loa. The long protected and old surfaces of the hilina pali will likely get extensively overflowed in this activity too, while the currently relatively young lava north of the east rift will probably be largely untouched for a long time until the new summit is able to get high enough to flow that way.

      • It would be interesting to be around to see that. Sadly I won’t be. A fascinating system! I appreciate your thorough knowledge of it all – the last eruption has been amazing to watch.

  7. A komatite volcano on land woud either form a flat fissure flood plain if eruptions at high eruptive rates.

    Or a very very very very flat low shield volcano at slow eruptive rates.
    Flows and hornitoes and flow lobes gets very small and delicate at this molten metal fluidity.

    A komtatite flow is much more fluid than Kilauea thoelite basalts or Nyiragongo nephelinite lavas

    Komatite lavas are even more fluid than Lengai but they are very very dense too

  8. Another nice and deep little swarm at “Greip”, southeast of Bárðarbunga. Waveform is clearly visible on the DYN drumplot.

    • If the chamber under BB is filling up from this spot, we should see a M4+ in the coming days, its due.

      • I tried to correlate the timing of swarms at Greip with the timing of M4+ BB quakes, but the timing seems random. A couple of times the two have been close in time, but most of the time they are not. BB could still draw magma from this point, but it’s not obvious from the quake data.

        BB is quite consistent in the average seismic moment release over time and given the time since the last large quake I would expect there is enough strain for an M4, but to get one of those >M4.8 I think we need at least one or two more months.

        • Waiting!! But at some timepoint the inflation should reach the pre-eruption level. When, and will there be a new Holohraun?

  9. Greip may be a forming magma chamber
    Being close to the plume source and at the spreading axis its high chance for that

  10. Im soure it will happen one day: one day Jupiter throws Comet Swift Tuttle into Earth.
    These two are for now in orbital resonace.

    Its going to be ugly.. 30 times more energy than the chicxulub event.
    We all will bake and broil under a glowing sky. Its going to be absoutley ugly if it happens.
    Earth for some days turns red with many white flashes on the nightside.
    Swift Tuttle is comming to get us all…
    Its the largest earth crossing object.
    Depending what Jupiter does it can be sent into space, into the Earth or into the sun. Here is a good article on Swift Tuttle written by an astrophysicist:
    https://www.forbes.com/sites/startswithabang/2016/08/11/the-most-dangerous-object-known-to-humanity/

    Now enough talk about that doomsaday rock pile

  11. And LoL even if taht one is avoided there will always be more
    The Ort Cloud is home to trillions of comet and frozen carbon rich volatile asteorids.
    Neaby stars as the pass often disturbs the ort cloud, sending deadly comets into the inner solar system.
    There will always be a supply of comets there are so many out there.
    These comets are so many that they will never runn out.
    There are so many that most of them will never hit the inner planets

    The only thing that will destroy the last ones is when universe dies of old age and the atoms in the comets decays. But the sun will be stone dead eons before that anyway

  12. The hottest Komatites in early Archean I read in a geological paper emerged at 1750 C
    thats freaking hot. Its so hot thats its like liquid sunlight in brightness almost.
    The days of these hot magmas are long gone.

    The magium lava temperatures today are likley 1500 C

  13. magine if Leilani 2018
    came directly from the hotspot!
    We say it was an intrusion directly from the
    1530 C Kilauea – Mauna Loa partial melting pool.
    The results woud be very scary indeed..
    The basalt woud flow out at over 1520 C
    Puna flows woud be white hot and flow watery like liquid slag. It woud be extremely fluid and Pour like water and spray like jets. Very much like the Liquid slag dumps
    The flows woud be just a centimeter thick or much less and form miniatyre pahoehoe and small lava channels. At 150 cubic meters a second it woud form a complex lava channel network

    Unless eruptive rates are super high .. souch flows woud end up very small

  14. OK… I have a question… How hot were the kimberlites that brought up diamonds? Does that still occasionally happen during the very biggest eruptions, or is Earth’s interior not hot enough anymore?

  15. Kimberlite is a cool extremely crystal rich ultramafic mush Albert
    Its totaly jam packed with Co2 too.
    Its AMAZING how these highly mafic gas rich magmas can penerate a 200 km thick craton!
    Kimberlites only erupts through thick cratons and how the @ is that possible Albert?
    How does a kimberlite gets through the worlds thickest litopsheres

    • The suggestion that it has CO2 is to provide the propulsion. It is a hypothesis: we don’t know it. It gets through small cracks. Kimberlite eruptions will always be small.

    • I noticed in a discussion about Colorado diamonds {linked above}, that there was some sort of CO interaction taking place during the diamonds forming at depth. Seeing that diamonds are pure carbon, and that CO2 and probably CO is involved… it all seems to fit quite nicely.

      Artificial diamonds use a gas {Plasma} rich in carbon to precipitate out onto a seed diamond lattice. (Methane+Hydrogen → I think the Hydrogen is used to control the concentration of carbon in order to manage the crystal growth rate; Methane ─► CH4, Molecular Hydrogen ─► H2)

      Note: Methane is also used in production of the Carbon-Carbon panels used for the Parker Solar Probe‘s heat shield. The molecules of the polymer binding the carbon fibre are replaced by pure carbon.… making it fairly robust. {Carbon sublimates at 3642° C. Tungsten melts at 3422° C.}

      “…Like the mission’s first perihelion in November 2018, Parker Solar Probe’s second perihelion in April will bring the spacecraft to a distance of about 15 million miles from the Sun – just over half the previous close solar approach record of about 27 million miles set by Helios 2 in 1976… {See Solar Probe Link for source}

  16. A Komatite eruption woud be alot like a flow of liquid iron slag in fluidity
    Liquid Iron slags are akin to an ultramafic andesite in iron content and sillica
    superhigh 1570 C temps makes it almost liquid like water

    Komatites with even less sillicon woud likley be even more fluid and much more dense.

  17. Kimberlite eruptions are very short lived
    Its akin to a huge vulcanian blast or very short violent subplinian one.
    Diatreme tuff and ash tephra rings are the products of souch rare superodd eruptions.
    A Kimberlite can never form a lava flow, its too gas rich and crystal rich for that it blows up.
    It gets very violent and and eruption likley last only a few minutes

    • Imagine the rush after the eruption when people try to find the diamonds!

    • Absoutley crazy it woud be!
      But most diamonds are tiny and not much to look at.
      But a few large ones may be found too.

  18. Komatite flows will be very very thin indeed!
    We are talking abour flow lobes and sheets just milimeters thick
    Cooled Komatite lavas looks like spilled molten iron slag

  19. Komatite pahoehoe will be a miniatyre version of basaltic pahoehoe
    Flow lobes and tounges very very very small and thin and intricate beacuse of Komatites high fluidty

  20. Imagine Komatite rivers flowing down a hadean era slope
    Glowing white hot and looks like a liquid slag dump hill.
    Flows pour quickly down in tiny narrow channels… white hot

    • The very fast lava river of Puna also was much thinner than it seemed on the video. Only the top layer went that fast. Komatiite will make laminar flows but if so thin, it could also cool quite fast. I am wondering whether it would form something like the pancake domes of Venus. (Of course, the large majority of komatiite flows will have formed under water as pillow lavas, something that Venus does not have.)

      • The river was about 20 meters deep near fissure 8, at least in that upper part probably the entire thing was moving at a constant velocity. Also it was not laminar at all near the vent, any close up video during a surge shows it being almost like a set of rapids.

        • Rapids are always shallow. The river was deep, but the flow speed was deceptive. The fast movement was confined to the top layer. That is characteristic of laminar flow. Because water does not behave like that (or at least not as much), the brain is deceived. At the point of the fissure the flow was turbulent, with lots of movement in all direction and without the change with depth. But turbulent flow is slower than it appears to be as so much of the pressure is wasted in going off in wrong directions. Same with traffic: turbulent traffic (lots of lane changes) gives much lower traffic flow.

        • Yes but the depth of the molten lava was not shallow, the bottom might gave been a bit slower but the channel was molten and about 20 meters deep and probably at about 10 meters above ground level. Overall the thickness of the lava is about 30 meters and then the cone is another 35 meters, so ahu’aila’au is about 65 meters tall from the pre-eruption ground. At its peak it was about 90 meters, quite a big cone especially as it formed mostly in about 5 days.

          • The channel was 20 m above ground level during surges, probably around 16 m during most of the time, measured with lidar. It was the thickest part of the flow if we ignore the lava delta. I don’t think there is any evidence for thermal erosion.

          • I was going off the drained channel measurements which I think are about 20 meters deep in the fast bit near the vent and 10 to 12 meters deep in the big ponded area. I dont know if there is any way if really telling if the bottom of the channel is at original ground level but it probably is slightly above.

          • The depth of the channel was impressive, as it build up over time. And the levies on either side never gave way which is also notable. But the point is that the flow speed varied a great deal with depth. Only the surface layer went at those incredible speeds. That was visible from the lava boats which got carried on the channel. These went much slower than the lava around them. Their speed showed how fast the lava was going below the surface.

            The bottom of the channel is a bit of a difficult one to define. The lava speed near the bottom was near zero (the viscosity anchors it to the bottom). If the situation had continued for much longer, the bottom would have solidified but over the two months or so the insulation was very effective. 20 meter depth may take 4-5 months to solidify (this is a bit on a guess on my part, scaling from 1 meter thickness taking a week). If the eruption had continued, I expect that the channel would have ruptured. In the end, the eruption ended quite fast. It became intermittent which is dangerous, but that didn’t last long. Leilani was lucky.

          • The channel next to halekamahina actually fully overflowed in the very last surge, if another happened then that area would have been flooded by the lava river.

          • Yes, those were dangerous events. But the levy itself held. Hawai’i lava is tough.

          • The levees of perched channels are very resistant, they grow over time as overflows of pahoehoe are piled up on the flank of channel. Each surge added more mass to the levee, as the channel grew taller the levees grew taller and wider. The part near Kapoho and Halekamahina was different, there it transitioned into a blocky channel and it was very unstable.

        • And an even better example, these guys took some epic footage.

          • Looks alot like Holhuraun at peak strenght
            But Baugur vent was quite bigger its 450 meters long

          • Mick kalbers video is incredible
            Mordors flows
            Its flowing freaking like a churned up river
            the fluidity here is amazing
            Extremely hot and fluid around 1195 C for Fissure 8
            All minerals molten.. only the olivine solid

        • Thats perhaps my favorite voclano video of fissure 8!
          Looook how its flowing! I wnats to take a canoe of titan and isulated with sillica foam and go down the flow!

          Ash nazg durbatulûk, ash nazg gimbatul, ash nazg thrakatulûk, agh burzum-ishi krimpatul!

      • Komatite can never form panacke domes Albert!
        venusian Pancake domes are high sillica rich magmas that formed from diffrentitaion in the crust.

        Komtities are so incredibely fluid they cannot even form normal pahohehoe flows
        Komatite pillow lavas? then the pillows must been very small beacuse of the high fluidty

        • See the picture in the post!

          To get the flat pancakes, you need quite fluid lava that flows for a fixed distance. It is not clear how they formed: the high surface temperature on Venus may have helped by slowing down the cooling. But is silica rich, it may be hard to keep it fluid enough for the material to become so flat. It looks like a shield volcano without any gradient – the flattest shield you can imagine. They go down a little in the centre but that is probably due to draining of the conduit after the eruption.

          • It was local sillica rich lavas likley dacite or ryholite that was keept hot by the hellish atmosphere.. and slowly cooled and spread out
            Its like an oversized version of earths obersdian domes and flows that forms from hot ryholites on earth

          • Venus is one big inferno… on the nightside the ground is hot enough
            To glow very very very very faintly dark red at 490 C

          • Likley not glowing since it needs little above 500 C for that
            But venus surface is almost there to be faint red in night darkness

          • Not just the surface. The air is 100 times denser than ours and equally hot

          • Walking through that is like going through airy liquid in a way
            The venusian air is indeed very dense

          • Hotter than Venusian Surface temperatures will engulf Earth for around 2 days if Swift Tuttle hits Earth and all rock vapour and ejecta reenters the atmosphere

  21. We had some more deep activity on/offshore of Pahala. Included with the 3 quakes the recorder shows some tremor. Tremor showing around the start of the quakes (12:07 utc) and running past the last quake and ends at around 12:45.

    2019-02-12 12:37:12 2.3 41.5
    2019-02-12 12:25:29 2.3 41.9
    2019-02-12 12:07:40 2.4 33.8

  22. Looking back over the past month, there are some small quakes at the centre of the Mauna Loa caldera. I think that is new: the quakes used to be along the north rim and the rift zone (the large majority still are). I gues it has to do with the continuing extension of the caldera.

    • I have noticed that we have more sharp rock cracking quakes (small tails) than I remember in the past. They seem to come in groups. I would guess that these are also part of the slow expansion.

  23. Probably nothing too significant, but just very recently some of the UWEV GPS circles made contact with the -0.3 meters line, which is quite a way above the median since the eruption last year ended. Might be a random signal but if this keeps going then we might be in for something pretty soon.

    • There also seems to be some signals on a few other GPS stations, mostly small but they all line up and look a bit more conspicuous than the other times a slight movement has occurred. Most are also moving east which is interesting, that might be caused by mauna loa because UWEV is also moving east…

    • Appart from the recent “bump”, whatever it is, most summit GPS have the vertical component flat or slightly deflating. Pu’u’o’o and JOKA continue to inflate, still probably far from any eruption.

      • Historically most small eruptions have been preceded by activity that is in the range of about 1-3 cm of uplift and so a small summit eruption like some of the 1961 eruptions is plausible even right now, the upper system is gone so if more magma rises then it will just erupt and not get stored within the summit area like it could have before. An eruption like this might be so small as to go unobserved though, there is no close view of the bottom of the caldera from the ground anywhere now.

        • The south caldera reservoir is still intact, it can get stored there. At OUTL it is even 10 cm more deflated than when the eruption ended, so far no signs of summit pressurization to me.

          • I still think a lot of that movement is because of slow summit settling as the area adjusts to having a massive new hole in the middle of it, the actual collapse was contained but the whole area around the summit sank by a large degree and all these areas are moving fault zones so of course they will move in response even if there is no actual earthquake. If there is any deflation from volcanic processes it is also probably because the rate of feed to the east rift is likely higher than the supply from depth after the rift was opened so much last year. The MERZ inflation is I think centered uprift of heiheiahulu now under tge 1977 vents though because the jonika station is not rising as much as it was before. With the rift so open now after 30 to maybe over 50 years of continuous feed along with several meters of deep spreading in 1975 and 2018 there is not a high chance of this being the end of any significant rift activity, and unlike after 1840 mauna loa isnt taking all the magma so I think things will probably go on pretty much as before last year once the refill is complete. 1975 took 8 years to recover from but last years quake was smaller so it likely wont take as long as that, maybe 5 years until a larger ERZ eruption can occur and maybe a few eruptions before that are small and brief. One thing that I also found interesting is that the elevation of the 1977 vents down to heiheiahulu is about the same as the bottom of halemaumau, probably coincidental but that could be why only this area is inflating.

  24. And in other news, the Mars rover Opportunity is unresponsive and presumed dead.

  25. Albert is it possible to predict Swift Tuttle orbit
    Beyond year 4400?

    I found someone on internet saying:
    ”Its possible to move its orbit with laser arrays and with very large nulcear bombs or use orbiting mirrors to shine sunlight at the right point in its rotation to send it away from the direction of Earth”

    Is this possible?

    Yuck I should stop being worry over this very large Earth crossing object

    • Not easy to predict that far ahead. It is currently in a resonance with Jupiter which will likely pull it towards the outer system, but this resonance is short lived. However, with so much time we could use a gravity tractor. Ideally, crash it into the moon.

    • Yes you should stop worrying its 100% not going to hit in your lifetime anyway

      • If you only worry about things that happen in your life time, you should become a politician. The essence of science is to look ahead further than that. Our children also count.

      • There is also a point where you have to be realistic about it all too. Some things require long thought but those are not everyday occurences, climate change is one where looking far is ok, but most aspects of our lives are much shorter. I have only fairly recently come to terms with this but I will never go back now, no im not a politician.

        Anyway swift tuttle is literally not going to even complete this current orbit before everyone born on earth up to today is dead so yes it is pretty pointless for anyone here now to worry, and even more if its orbits for the next 4000 years are known and all misses. Sending a nuke to it will never work either, not even a tsar bomba would do it and good luck getting one of those (nevermind anything bigger) into space and then accelerate it to a velocity capable of getting it near something that covers the earth-moon distance in less than 2 hours…

        • Wrong, I think. Asteroids can be moved given enough time. Don’t use explosive events: it is enough to apply a small push. In this case, a gravity tractor. It may need a thousand years to change the orbit, but we have the time. For something as dangerous as Swift-Tuttle, it it worth getting it right. The chance of a collision is around 10^-8 per orbit. Over the remaining time for life on Earth (1 billion years), that gives a 10% chance of a collision. High enough to do something about it.

          There are many things that require forecasting and planning beyond a politician’s attention span. Climate change: the quoted numbers tend to be for 2100, while the really big changes come in the decades after that. Population: the peak is around 2050 but the big challenges come after when population may be slowly declining but our resources will be heavily depleted. Long term planning is essential. Swift-Tuttle is a solvable problem – but ignoring it does not work. The planning will take a century and the execution a millennium.

    • Yes, I saw that. Very speculative. But geothermal activity below the Martian surface is not unlikely – I just don’t buy this particular one.

    • Nice toy to play with! Wonder what data they will get out of it. Must have got a considerable amount of funding!

  26. Oppurtunity will never come back to life, its been there for almost 15 years and its pretty much done.
    Sand and particles have worn it out and solar planels are done. Electic systems are old too
    Now its a junkheap that will slowly erode away by meteors and sandblasting and be liley buried one day

    • The failure is likely in the charging of the batteries. The solar panels are covered in dust, and the batteries don’t work without any heating. If someone would go there, wipe the panels and turn on the heater, chances are it would come back to life.

  27. I wonder if a Venus rover will be possible one day………
    But the problem is the heat … the heat will always get into the rover according to laws of thermodynamics and cooling systems cannot go on work/ forever.
    Electronics also preforms horrrible in these high temperatures.
    batteries explodes in high temperatures, electronics overheats.
    The mecanical structures also swell in the heat jamming the Venus Curisosity

    I burned my old dead Iphone 7 in our fireplace at 950 C and it exploded in a loud bang
    Electronics and heat simply dont work togther

    • True. Heat and pressure is what limited the life time of the Venera probes to about an hour. That is how long it managed to keep the Venusian air out.

      • Phones becomes very explosive in hot enviroment
        I put my comatose Iphone 7 in the fire, the screen swelled and
        Kaboooooooooooooooom after 1,5 minutes
        It blew very loud and formed almost a firework like explosion with “stars”
        Its a horrible smell too.
        Do NOT burn electronics! as the sign on the back says do not incenirate.
        I did it just for fun and I will never do it again.. it coud have damaged our firebox furnace in Our living and TV room. No electronics in fires

  28. https://www.volcanocafe.org/the-fall-of-surtsey/
    Albert
    Just a correction here. ( sorry being nerdfy ) You writes that surtsey became strombolian after the surtseyan phase…Thats totaly wrong. Surtsey was way more fluid than that.

    Surtsey became a fluid Hawaiian style eruption once the conduits where insulated from seawater.
    Surtur phase 1964 basalts where hot ( 1160 C ) and formed highly fluid pahoehoes.
    Surtsey formed a lava shield that consistsed of pahohehoe lavas.
    In 1964 the lava from the lava lake in Surtungur flowed constantly forming pahoehoe fields and many lava tubes. The lava tubes from the subarial carried the lava below sealevel underwater and it keept flowing for year without surface flows. That phase ended in 1965, with a pahoehoe shield of 0,5km3 built.
    In total Surtsey erupted 1,3km3 of lava.

    Here is an absoutley excellent text about surtsey lavas: https://books.google.se/books?id=7-l_65bugsoC&pg=PA53&lpg=PA53&dq=effusive+activity+in+the+1963+-+1967+surtsey+eruption,+flow+and+emplacement+of+lava+shields&source=bl&ots=OM161KkAw1&sig=ACfU3U3NZQv_edUqn_r6jjjXsJr8zdcuzQ&hl=sv&sa=X&ved=2ahUKEwjvhuWqzLvgAhUQ0qYKHQD6AogQ6AEwA3oECAcQAQ#v=onepage&q=effusive%20activity%20in%20the%201963%20-%201967%20surtsey%20eruption%2C%20flow%20and%20emplacement%20of%20lava%20shields&f=false

  29. OT well the sun finally hit the window this morning and i thought…………. “WOW!…….. i’ve got to clean that.” Best!motsfo

    • Any snow? we’ve been getting on and off snow since Feb1st in NE Oregon.
      the Polar je tis going to have its way with Oregon (again next week, I’m told..

      • There’s 2 feet out there from previous falls and more will come in the future but there was sun today snd sun due tomorrow but the cloudless skies make it colder down into the minus F’s but i can stand it… really missing the sun this winter…. i’ve decided to be extra nice to myself for the next 30 days. (half way thu Feb to half way thu March is my worst month of the year) Extra Nice…. ((like always 🙂 )) Best!motsfo

        • Beach holiday would be nice? There are some nice volcanoes near warm seas.

          • Can’t blame Hubby’s Parkinson’s for this one; i have very bad back and have trouble travelling but why would i leave and miss the (CENSORED) going on in my country… and i can see Redoubt from here (if not Russia; altho i’ve waved to Migs from my beach) So here’s a tip to everyone….. You never know when old age will make travel more uncomfortable than just staying home. Besides i can travel to EVERY volcano from my computer and still stay warm and dry. So Off to another adventure, everyone… take the trip sooner than later. Best!motsfo

          • And that is good advice for anyone. Now I am curious where you could see both Russia and Redoubt – from the space station, perhaps?

  30. “Mad science means you never have to worry about:what is the worst possible outcome?” I like the scientist guy running/explaining the program. Liquid sodium is nasty stuff. been around it a bit.. You throw oyut every thing you knew about how to handle a fire. Do not let that material come in contact with water…

    • Yeah, but at least their mitigation plan seems to have some thought put into it. Flood the thing with Liquid Nitrogen. That serves two purposes, it smothers any incidental fires that are triggered, and it might get the liquid sodium down to a temp where it’s reaction might actually slow down.

      Cooling it down is actually a workable idea. I managed to get a VW microbus’s engine block down to a point where it quit spitting fireballs out at me. But it took a whole truckload of water and two of us laying on the hose to stay in control of it. (solid stream) This all started because I mistakenly put water where I thought the fuel tank was at. Surprised the crap out of me wen it spit fire back out at me. The pump operator freaked a bit as well and cranked up the throttle for the PTO. Next thing I know I’m laying on this hose and my backup hose-man is laying on my back as it’s trying to lift me up.

      • Sodium doesnt react with nitrogen, only lithium does out of all the alkali metals. Sodium nitride can only be made by decomposing sodium amide which is made by dissolving sodium in anhydrous ammonia. If this was a ball of molten lithium then basically nothing will put out that fire, even smothering it in argon will do nothing because the metal will undergo a very exothermic redox reaction with basically everything in the room that has reacted with oxygen (lithium is the strongest reducing agent that exists and really likes reacting with oxygen).

        Titanium and zirconium also burn in nitrogen but if you have a sphere full of liquid Ti or Zr then you are playing with something that literally freezes on contact with freshly erupted lava but before that happens they are both violently reactive with oxygen and burn at over 4000 C…..

        While we are on this subject, probably the worst fire possible, meaning the most energetic, lithium borohydride in either ozone or fluorine.
        If you are brave enough you can look at the energy involved… I dont think anyone has ever done it but the heat of reaction of neutral H2 (H is negative in BH4 so even more energy) and F2 is enough to evaporate elemental carbon so I think that says enough. If you want to go all out and really get your moneys worth you can use oxygen difluoride as both an oxidiser and a solvent for the O3 and F2, and maybe add some KrF2 because it is spicy.

        Also LiBH4 has a density of 666 kg/m3 😀

        (maybe also reverse NaH in fluorine, contains the Na- anion, and yes it does exist)

        • I ”cremated” my dead Iphone 7 in our fireplace.. as hot as a cold basalt
          Is this lithium – sodium thing why the batteries explodes when you Burns phones and other electronics?
          Very loud bang in the fire and ”glowing stars” possible magnesium…
          why do phones go crazy in fires?
          Do not burn electronics!

        • I wonder what will happen if I burns my old dead Playstation 2
          At parents summerhouse backyard…
          Electronics can be explosive
          I lives extremely far north and the heavy snow wont allow acess to backyard until may.

          • Kids – please don’t try this at home!

            Seriously – i’d be very cautious about burning any electrical equipment, especially Li batteries that may contain PTFE as this could generate HF (hydrogen fluoride) residues in the ash and emissions.
            I’m a chemist of too many years experience, i’ve handled plenty of “nasties” in my time but HF is the one substance that makes most chemists a little nervous.

          • Addendum – i typed PTFE courtesy of a brain fart (although this is used in most electronics and batteries). The HF issue with Li batteries is actually down to fluoride salts in the lithium gels.

            Same warning still – don’t burn batteries/electronics.

      • Liquid nitrogen is not ideal. It has a very low heat of evaporation and tends to form a gas layer insulating the liquid from the stuff its dumped on. I once (decades ago) bet another student £5 (a LOT of money in the 60’s) that I wouldn’t put my hand in a dewar of liquid N2 to my wrist. I did with no ill effects and before I could stop him he followed suit.

        But he had a lot of rings on his fingers ….

        Risk must be associated with knowledge.

        I doubt the liquid N2 would work. Better would be oil, possibly silicone based.

        • Its more that N2 is not oxygen, so the sodium cant burn in it and then once it is solid it is pretty safe.

        • Agree! I have handled and spilled liquid N2 for many years. It just floats of your skin. BUT if you get it into your glove (better not use gloves) or into your pockets or shoes, it will cause severe tissue damages

          • Yes indeed. Given the design I am pretty confident the N2 would flow over the sodium and end up uselessly on the floor without doing much cooling. They are not proposing to fill the room and the volume wouldn’t fill the experimental chamber even assuming it was airtight (which it didn’t seem to be).

            Also noted is the safety issue that you are better off NOT wearing gloves, knowledge over dogma any day.

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