The Terraces of Tarawera

The Haszard family at Te Wairoa. Charles Haszard was the local school teacher. Source: Alexander Turnbull Library

It was a quintessential English village, with simple houses along streets and fenced cottage gardens of precisely 100 m2 each. This is what the heart of England, the Cotswolds, looked like. Perhaps 85% of the population was local; the others were distant immigrants. The people were farmers and workers in the local flour mill. But although typical, this village would have an exceptional legacy. It was the only English village ever to be destroyed by a volcanic eruption.

The location gives a clue. For this was the England of the colonies, and the immigrants were people who had left their home in England – not always voluntary – and traveled halfway across the world to start a new life. This was about as far from England as it was possible to get. The fact that their new homeland was already occupied was not seen as a problem, in the colonial era. The local population could provide the labour for the new arrivals.

Some saw a wider responsibility, and took it on themselves to develop the local population, the Maori, by teaching them civilized ways. Te Wairoa, on the North Island of New Zealand, was designed and build as a model village which would help educate the Maori – and would help them become more English. The intention may have been good (although this is disputed), but it was misguided. A culture grows over centuries; transposing and imposing a culture from one country to another never works. English houses and factories, and English agriculture (wheat) were a poor match to the Maori way of life. Over time, conflicts grew about land use, with different Maori tribes claiming ownership. During these years Te Wairoa was abandoned, but eventually an arrangement was reached between the warring tribes and people returned. But the factory and church became abandoned and the original English colonizers, with all their good intentions, were slowly leaving. A new way of life developed, but it was very different from what either side of the divide had envisaged. Nature finally stepped in and brought the culture war to a close.

The location of Te Wairoa had been well chosen, in a fertile valley in between steep mountain sides and in between two lakes. One of those lakes, Lake Rotomohana, contained a marvellous and world-famous attraction: the Pink and White Terraces. Once the land dispute had been settled and the area became safe to visit, people came from far and wide. And the tourists kept coming. They would travel to New Zealand just to see this. Quickly, tourism became a better source of income than English agriculture. The viewing experience was well organised. A sign at the entrance to Te Wairoa listed the exact charges for guiding. Every day during the season, some 20 people would visit the Terraces on a strict itinerary: evening entertainment in the village, travel by canoe to visit the White Terraces at 11 am, lunch with boiled crayfish at one of the hot springs, afternoon bathing at the Pink Terraces, and return to Te Wairoa where there would be concerts and dancing. The guiding was largely done by women. The local Maori became well off. This also brought a new group of English with commercial interests, and they owned the local businesses and hotels. By the end, some 120 Maori and 15 Europeans lived in the village. Alcoholism had become a problem.

The end came suddenly. In the previous days, one of the Maori guides had noted an increase in hydrothermal activity at the lake. Apart from this, there was no warning. Soon after midnight on June 10, 1886, an earthquake swarm started, which increased in strength. The eruption itself began around 2am with a “roar like a tornado”. Te Wairoa found itself next to the second largest eruption to hit New Zealand since the arrival of the Maori. When morning came, the village no longer existed.

The mountain itself was hidden from view from Te Wairoa, and the main eye witness accounts are from further away. They describe the onset: “There was no sign of a storm, the wind was steady and the stars shining; but right over the eastern end of Ruawahia was a high, thin column of black smoke with a spreading top looking not unlike an immense mushroom. All this smoke cloud was blazing with lightning, which scintillated through every part of it and, shooting out from its dark edges fringed them with vivid light. The total height of this column when first seen would have been about 5000 feet; and it stood quite straight as though not subject to the action of any wind….”

(The quotation is taken from Keam 2015. Sources for the post are listed at the end.) The observer saw flames rising 500 meter high coming from the top of Tarawera mountain. And shortly after, perhaps around 3am, a large explosion was seen some 10 kilometer southwest of the mountain; the cloud, first white, then black, rolled across the landscape. It rendered the remainder of the eruption invisible.

This large explosion had happened under Lake Rotomahana, the lake southeast of Te Wairoa. The cloud that it generated was not just ash and smoke. The bottom of the lake had blown up, and the cloud brought a rain of mud, stones and cinders which lasted for 3 hours. Te Wairoa was buried under a meter of mud; other places were hit even harder. There are desperate descriptions of people trying in vain to support the roofs of their homes. Some died in the collapses, others escaped into the streets enduring the rain of mud and stones.

The school house of Te Wairoa, July 1886. The school teacher, his son and two of his daughters had died in the eruption. Source: Alexander Turnbull Library

There had been many more explosions, but they had been unobserved behind the cloud of mud. A 16-km long, straight rift had opened, running from the mountain through Lake Rotomahana and beyond. The explosions that occurred as the rising magma met the ground water thundered across the landscape. They were heard 130 km away on the North Island, and even people in Christ Church, on the South Island, noted the distant explosions. In Auckland, the explosions were first heard around 2:30am, and lasted until after 4am. At the coast the black cloud brought darkness; even ships at sea found themselves under a rain of ash.

When the eruption was over, around 6:30am and after only 4 hours, some 120 people had died. It had been the end of the tourist season and only three tourists had been staying at the local hotels. But there had been a Maori wedding that evening and guests had come for that. A few of the smaller Maori dwellings survived better than the large houses, but most of the 70 houses, the village hall, the hotels and the factory were destroyed. Survivors had been propping up the roofs against the weight of the mud. Other had fled the collapsing buildings. In the morning people started digging out the survivors. 11 inhabitants of Te Wairoa had died. But there had been several small settlements around the shore of Lake Rotomahana, and those had been completely destroyed. Here, only a single person survived.

Te Wairoa was never rebuild, although for a while it still attracted tourists who came to view the destruction. Te Wairoa is now mainly known as New Zealand’s best known archeological site.

A mountain split

Summit fissure (source: photovolcanica)

The eruption had occurred along a straight and fairly narrow rift. It started at the northeast side of the summit of Tarawera, where afterwards there were two craters. From here the rift passed southwest through the extended summit where the three domes had split completely. The summit was covered in pyroclastic ejecta which in places reached 75 meters in thickness. After a short gap, the rift continued along the southwest slope down the mountain. Beyond that there was a further rift sections and craters, which terminated at the newly formed Rotomahana crater. After another gap, there more craters further southwest for another 3 kilometers, in the Waimangu section. The penultimate one was Waimanga (Black crater).

The 1886 rift eruption

The summit rift showed 13 separate craters, and as many as 50 vents. The Rotomahana section had at least 4 craters, and the Waimangu section had a line of craters which still showed minor hydrothermal explosions years after the eruption had ended.

Echo crater (source: photovolcanica)

The Waimangu section remained hydrothermally active for even longer. Black crater surprised everyone when fourteen years after the eruption it suddenly developed a large geyser. The geyser is still listed as the largest known: at times it erupted 400 meters high. The geyser activity ended after 4 years. Nowadays it is known as Echo crater and although the geyser is gone, there is still a hot spring which erupted mud as recently as 2016.

The summit eruption was plinian and it was basaltic. That is an unusual combination. Basalt tends to erupt effusively, without large explosions, because it does not have much volatile content which can drive explosions. And whereas basaltic plinian eruptions are already rare, Tarawera is unique in doing it simultaneously along such a long rift with so many individual eruption locations. And even stranger, Tarawera is not a basaltic volcano. Previous eruptions here produced rhyolite, with only very minor basaltic components. It appears that often, the rhyolite eruptions were triggered by a small basaltic intrusion, but the eruptions came from the activated rhyolite magma chambers. But in this case, the basalt came up and bypassed any rhyolite magma that may have been present. A dike was emplaced underneath the summit (possibly two dikes of which only one reached the surface) and very rapidly progressed along the rift direction. At the lowest point along the rift, where Lake Rotomahana was located, it produced massive phreato-magmatic explosions (i.e. water-magma interaction). The Rotomahana crater left by these explosions was 2.5 kilometers across. Further down-rift the explosions were equally watery but smaller.

The rift as it was shortly after the 1886 eruption.

And the explosions at the summit should not be underestimated either. Here, no water was involved. The scoria that was ejected from the summit covered an area of 10,000 km2. The wind blew the ejecta north and northeast, towards Whakatane. The plinian eruption appears to have come from four of the 13 summit craters, with eruptions speeds of 300 m/s. The other craters erupted with less intensity, and build smaller scoria deposits within about 500 meters of the rift.

The structure and composition of the basaltic ejecta indicates that the magma had been relatively cool, at 1100C (this is the temperature in the dike underground – not the lava ejection temperature which is rarely known) and had been fairly shallow (1-2 kbar, or 2-3 km depth). The reason why there was only 1-2 hours of earthquake activity prior to the eruption was that the dike was already quite close to the surface. But there was no existing conduit, and instead the dike ripped open the entire summit. The northeast-southwest direction which the dike and rift followed is a common alignment at Tarawera. The sides of the rift show some sideways shift, perhaps caused by a combination of some extension and rotation. The stress field made it easy for the dike to push its way out and up along this path.

The ejecta at Rotomahana were different from those from the summit craters. This was the so-called Rotomahana mud. It too contained basalt, but this was only around 20% of the ejecta. The rest was pulverized ground. The soil and rock around Tarawera are from older, rhyolitic eruptions. This was taken up in the ejecta, which became a mix of fresh basalt and ancient, cold rhyolite. In fact the same mixture is seen at the summit but with a much higher percentage of basalt, of up to 85%.

Rotomahana mud

The Rotomahana mud formed a dune field, extending up to 6 kilometers from the new crater. This indicates a base surge. The fact that the distance observer saw the explosion causing first a white and then a black cloud also points at this. Base surges are common in phreato-magmatic (shallow underground) explosions. The gas vents vertically out of the crater hole, flows over the crater edge and moves out horizontally over the ground, as an expanding ring around the explosion column. The surge cloud hugs the ground while moving out at speeds of typically 50 m/s (100 miles/hour, if you prefer these units). The surge carries the ash, mud and even stones, well beyond distances to which the rocks could be thrown by the eruption. Te Wairoa was hit by such a base surge.

Te Wairoa after the eruption. The building is a part of the old flour mill. The dune field left by the base surge is clearly visible.

The deposits change from the deep mud near the lake to a volcanic ‘flour’ further away. The two have the same composition, but the water-soaked material dropped out of the surge closer to the lake, with the dry ash traveling further. This is also the cause of the change from a white (vapour) to a black (dust) cloud. Layering of the ejecta shows that the surge dried out later in the eruption, with a thin layer of flour dropped on top of the thick mud. Whether this was because the water in the lake had all been used up, or that the mud ceased to be carried as far as the eruption declined, is an open question. The dry flour consists mainly of old rhyolitic deposits, remobilized by the explosion, with some 20% fresh basalt. The temperature of the dry flour may have been as high as 150C: trees in the region were scorched, showing the base surge was hot (unlike ash fall which is cold). But it was not as hot as a pyroclastic flow would have been, and perhaps the water in the mud kept the temperature down around the lake since none of the reports of the eruption mention heat.

The eruption was very destructive. In those four hours, some 1.3 to 2 km3 of pulverized rock, scoria and lava was ejected, making this a VEI 5 eruption. The numbers are based on several different and independent measurements of the thickness and extent of the deposits. About half the volume came from the summit eruption, and half from the Rotomahana explosion. But most of the lava came from the summit: Rotomahana contained less than 1/5th of the ejected basalt. This is an indication that the power of the Rotomahana explosion came from the interaction with the lake water. The basaltic lava itself had relatively little volatiles (less than 2% water content), and the plinian summit eruption instead was driven by the straight pressure on the dike. In contrast, the lake provided volatiles and turned what would otherwise have been a smaller explosion far along the rift into a borderline VEI-5. Phreato-magmatic eruptions are far more dangerous than the amount of lava involved may suggest. At Tarawera, all of the casualties came from the lake explosion.

The region has changed in the 135 year since the eruption. The volcanic grey, impassable wilderness has greened. The craters are filled with water, and formed new lakes with new outflows. Not all of the 1886 craters are still recognizable in the landscape. Rotomahana crater too has became a lake, different in shape to lake that went before. The level of the lake is much higher than it was before the eruption: the original outflow was blocked after the eruption. New thermal fields and hot springs have developed. There are now geysers along the western side of Lake Rotomahana. As the lake level rises and falls, different geysers become active; geyser activity is seen if the exit is no more than 3 meters above the level of the lake. When the lake drops, geysers higher up may still discharge warm water but do so without steam explosions, while new geysers appear lower down.

But this hydrothermal activity cannot undo the damage of the eruption. Te Wairou lost its village – and its biggest attraction.

The Pink and White Terraces

The world-famous White Terraces, cascading down the mountain. The Pink Terraces were a separate, smaller cascade

It was know as the 8th wonder of the world. This title may be queried. The original, ancient list had contained nine world wonders, leaving no vacancy at number 8. And there is competition for the title: many things have been called the 8th wonder. The strangest one, perhaps was the suggestion by Albert Einstein of compound interest: he reportedly said “He who understands it, earns it; he who doesn’t, pays it.” Even King Kong was nominated at one time. The Taj Mahal and the Grand Canyon are on the list. The Taj Mahal would qualify, as the original list was about marvels of engineering, not those of nature. But all visitors agreed that the Pink and White Terraces were a world-class marvel. Therefore, after the Rotohamana explosion, people quickly went to see the damage to them.

They could not even decide where the Terraces had been. Not enough of the landscape had survived for them to get their bearings. The Auckland Evening Star newspaper described the scene, shortly after the eruption: “.instead of a splendid sheet of water, there was opened out immediately beneath our feet, its edge not 250 yards distant, a huge crater, belching out showers of mud and stones from innumerable yawning mouths, amid dense volumes of steam and smoke, with a din and roar and rattle baffling description. Stones were being ejected high into the air from eleven separate orifices or small craters, on the side nearest to us, and the volumes of steam and smoke prevented further vision into the centre of the old lake site. A partial clearing away of the vaporous envelope, however, occasionally gave a brief glimpse into the gloomy recesses of the great crater revealing only a bed of steaming seething mud in flats and hillocks, bubbling and spouting in ceaseless ebullition. A small patch of discoloured water was dimly distinguishable in one part, but the lake was gone—not only the water, but the bottom driven out, scooping the bed to a depth of at least 250 feet below the old level…. The great crater was over a mile long and half a mile wide.

And together with the lake, the Pink and White Terraces too were gone. People have been looking for the remnants ever since. The largest explosion happened very close to the White Terraces and it is unlikely any part of it survived. But the Pink Terraces were further away: are they perhaps just buried underneath the 10 or 15 meters of mud? The ejecta covering Te Wairoa and surrounding areas included many silica fragments which resembled the material of the Terraces, but we do not know whether they come from one or both Terraces. Every now and then a report comes out that remnants of the Terraces have been located deep under the lake. But these reports have not been confirmed and the claims do not agree with each other. The lake has risen by 30 meters or more and any remnant would now be under water. But this rise came slowly after the eruption, and the early searches had a dry view of any surviving areas. Even if they had been buried by deep Rotomahana mud, part of them could easily have been uncovered as the mud was washed away. The steps between Terraces could be several meters. It therefore seems likely that the Pink Terraces too were mostly or fully destroyed. Only one of the original ancient world wonders survives, so this puts the Terraces in good company. But there is always hope and perhaps one day the remnants will be uncovered.

Volcanoes continuously redevelop the land they occupy. What they destroy may well over time reform. But so far, the famous Terraces show no sign of being recreated.

The name Lake Rotomahana means ‘warm lake’ and this is already an indication of the hydrothermal activity in the region. The White Terraces, on the northeastern shore of the lake, were fed from the Te Tarata geyser 30 meters above the lake. (The same name was also used for the Terraces themselves.) The silica-rich water descended from here to the lake, depositing the Terraces in the process with some 50 large pools and many more small ones. The Pink Terraces were smaller and on the opposite shore, and came from a spring also located 30 meters high, along a steep valley. The Pink Terraces were not pink everywhere: they were marble white at the bottom, but turned pink and rose higher up; the pool at the top was cobalt blue. The upper pools of the Pink Terraces had the best temperature for bathing.

Similar cinter terraces exist elsewhere in the world, for instance at Mammoth Springs in Yellowstone and Pamukkale in Turkey. Those at Rotomahana were larger and (reportedly) more impressive. It was also unique to have two such wonders on the same lake.

Pummakale, Turkey (image from wikipedia)

Before the eruption, the lake was bordered on its eastern side by a 50-meter high ridge. This ridge may have been the wall of an older caldera. The Te Tarata geyser was located on the slope of this ridge. The sketch below is the only map in existence of the old lake. The Terraces are the larger yellow areas near the bottom left (the Pink Terraces) and the centre (the White Terraces). The Pink Terraces were fed by a spring with a temperature of 80C, while the White Terraces came from a boiling intermittent geyser. The other yellow areas were fed by cooler springs which had deposited silica on the valley floors but which had not developed the silica basins of the Terraces. Temperature matters.

And the temperature was impressive. The geologist Hochstetter once camped on the small Puqi island in Rotomahana. He was not comfortable: “The whole ground is . . . so warm from below that I started from my couch unable to bear it any longer”. He put a thermometer into the ground. When pulling it out, hot steam came from the hole.

from Keam 2015

It is notable that the various cool springs, hot springs and geysers were some 30 meters above the lake level. That is very different from the current situation where the new geysers are found below 3 meters above the lake level (albeit with a much higher lake level.) It is clear that the water supply for those pre-1886 springs and geysers did not come from the lake, but benefitted from much higher pressure than provided by the water. The geyser water had been in contact with hot rocks, which were likely to have been at some depth. Indeed, ground water can circulate to kilometers depth. Rising to the surface, it avoided the lake. Instead the water came up through the ridge next to the lake, perhaps following an old eruption conduit.

Plausibly, that the water got its pressure from Tarawera, and came down underground from the summit, following a flow channel at some depth. This underground direction which also brought it in contact with the warm (even hot) heart of the mountain. The dike of the 1886 eruption followed the same direction. When the magma came, it found the water already along the rift, ready to power the explosions.

This water flow must have been stable over a long time. Estimates for how long it may have taken to build up the Terraces range from 1000 to 10,000 years. And this happened while the lake level fluctuated and the volcano cycled through its phases of activity. The Terraces formed in a most unlikely location. Geyser fields normally indicate a deeply dormant volcano.

Where did the silica that formed the Terraces come from? The region was covered in old rhyolitic deposits, and rhyolite has a very high percentage of silica. Silica is slow to dissolve in water, however this becomes much faster when the water is very hot: the solubility peaks at around 300C, which obviously requires high pressure. As the water reaches the surface, it rapidly cools and the silica precipitates again, covering the valley floor in silica. This happens in the Hidden Valley in nearby Taupo, as shown in this video. The colours in the video are caused by microbes. In contrast, the colour of the Pink Terraces was intrinsic to the silica. The precise origin is not known, but trace elements in the silica such as iron are likely to blame. (Even gold has been suggested, perhaps a bit optimistic!)

To turn a silica-rich water flow into the Terraces requires a largely flat area where the water can be caught behind small barriers. The ponded water itself now creates a level surface where the silica is deposited on the floor of the pool. As it flows over the barrier, it also deposited here. The barrier grows higher and eventually the standing water becomes a proper pool and a Terrace. The dripping water on the outside of the step barrier can cause stalactite-like formations, which did indeed exist on the Pink and White Terraces. Building such structures takes time. A shorter-lived flow will only cause a white surface, as in the Hidden Valley.

Photograph of the White Terraces, taken between 1880 and 1886

Heat measurements have shown that the hydrothermal system beneath the Pink Terraces still exists. The hot water now mainly exits below the lake, but there are also geysers along the western shore. Gravity anomalies suggest there may be a basaltic dike hiding here underneath the old rhyolite ridge, a remnant of the 1886 eruption. But there is no heat signature at this location of the White Terraces, and its hydrothermal system was likely fully destroyed in the explosions. If the Terraces ever do re-form, it will not be in the same location. And probably, they never will. We are left with memories of a misguided model village and a world-class attraction.

Post and future

Tarawera has a dangerous side. Over many years it build up a world wonder, only to destroy it in just a few hours. This was never a safe place to build a model English village. The land disputes were settled once and for all, once the volcano showed what it was capable of. But the Maori could have known. The 1886 eruption was the second largest eruption since the New Zealand settlement. The largest eruption had happened some 500 year earlier. This early eruption is a key moment not just in the settlement of New Zealand, but even in the peopling of the Pacific. But that is another story.

Albert, November 2021

Sources

Te Wairoa, The Buried Village: A Summary of Recent Research and Excavations. Alexy Simmons, 1991. Australian Journal of Historical Archaeology, Vol. 9 (1991), pp. 56-62

The Tarawera eruption, Lake Rotomahana, and the origin of the Pink and White Terraces. Ronald Keam, 2015, Journal of Volcanology and Geothermal Research, 314, Pages 10-38

Tarawera 1886: an integrated review of volcanological and geochemical characteristics of a complex basaltic eruption. Michael C. Rowe, Rebecca J. Carey, James D. L. White, et al., 2021. New Zealand Journal of Geology and Geophysics, 64:2-3, 296-319,

599 thoughts on “The Terraces of Tarawera

  1. Thank you Albert for the article. I keep wondering why we humans keep building near or on volcanoes?

  2. “…next to the second largest eruption to hit New Zealand since the arrival of the Maori…”

    Curious, what do you think was larger than Tarawera?

    I’ve always regarded Tarawera as a serious warning; I wonder just how much additional warning we would have even with modern techniques; a bloody great basaltic dyke ascending rapidly from depth and a VEI 5 over and done with between midnight and breakfast time is a frightening concept!

      • Let me guess – Tarawera (The Kaharoa eruption in the 14th Century CE) and Rangitoto in the 14/15th Century?

        Rangitoto’s VEI is not listed in the GVP site, but it was certainly quite voluminous – about 2.3 cu. km! There are indeed Māori legends attesting to this volcano – and even human footprints on its slopes. There’s also some evidence that the Māori apparently were in the area of Tarawera when it went up big time in the 14th Century.

    • Tarawera woud be like opening the gates of doom .. the lava fountains where probaly 3 kilometers tall, with ligthing flashes inside them, and white hot in the night, lots of dark tephra too, a gigantic pyrocumulus spread upwards.The opening woud perhaps look like the Tsar bombas cumulus condensation. It woud be a sight from hell. The lava fountains where so violent it formed a lava spray and No lava flows at all acually. A truely develish sight it must have been, Mega pyrocumulus condensation and Ligthing enraged lava fountains. The magma involved was insanely gas rich

      • It sourely had violent fountains, so violent it did not form much lava flows at all .. the magma was a primitive picrite mafic melt involved

        • The fountains were reported as about 500 meters tall. The magma was rather gas-poor, and somewhat evolved, not particularly primitive. The low temperature is a hint: the magma spend time at fairly shallow depths.

          • There is one source I found that a less violent section of the fissure preserved a part of the dike. There was signs of remelting of the rhyolite and the authors attribute this to a very high magma temperature. This is also generally required to explain the huge volumes of rhyolite, which needs enormous heat input.
            Not sure I agree with such a relatively low temperature.

          • The magma temperature comes from the crystallization in the basalt. It depends a little on assumed water content, but the pyroxene crystals grew at a pressure of around 2kbar and a temperature between 1050C (assuming 5% water) and 1100C (assuming no water). Obviously the magma originally came from much deeper. It was emplaced as a dike and spend some time there. These are the conditions in the dike. Rhyolite crystals were incorporated in the melt but these came from several older eruptions. There is some fusing between rhyolite crystals but no significant remelting.

        • Chad is correct
          The massive subalkaline normal ryholite magmatism in the TVZ requires a gigantic heat input that comes from upwellings in the back arc rifting there. TVZ is huge it goes all way from Rupeahu and all way into the pacific ocean and keeps going for a good distance offshore. Part of an almost 3000 kilometers long belt of backarc rifting. But the Ryholite Productivity is perhaps more intense in New Zeeland with the continetal crust there. The whole region there haves a huge supply, But the supply in TVZ per square kilometer are not very Big, unlike real plumes like Hawaii and Iceland

        • Its still very hot in TVZ .. the basaltic magmas of other subduction zones can be hot too. Example Ambrym is too in a Subduction Zone enviroment, and they go up to 1160 C and are Highly fluid. And Masaya that too goes up to 1160 C is another very very hot fluid subduction melt.

          West Mata another subduction zone volcano is even much much hotter eruption temperatures than that, it erupts an odd ultramafic andesite, that formed white hot pillow lavas as it extruded. But west matas Young subduction crust zone have not formed a thick felsic crust yet, making it easier for hot melts to rise to the surface

          • Maybe some help: Draw a line between the TPZ and Raoul Island for the whole picture. You see lots of submarine volcanoes along the line. Then take the line NNW, and you get to Tonga. One long subduction zone with the old Chap Pacific Plate (or old Lady) subducting.
            Two crater lakes on Raoul. This is Blue Lake:

            North Island is the southern end.

      • The poetic imagery in Jesper is most elegant as is Albert’s research and consolidation into informative narrative.

      • Then the sources I read it is wrong then? Many papers write is as primitive melt from TVZ s deeper parts

        • Which is basalt. But basalt is not normally gas-rich (unless from water-saturated mantle), and it can still be very primitive or it can be evolved, i.e. having spend some time at lower temperature where crystals can form. In this case the basalt was low in water content, was rather cool and evolved, and had also picked up crystals from the rhyolitic crust.

  3. Chapter 29 treats of it, and Plate 14 in Jagger’s ‘Volcanoes Declare War’ contains some old photos of the post-eruption Tarawera/Rotomahana event. After more than 7 decades these words and images have finally crystalized.

  4. Many thanks for another great scholarly article! I very much enjoyed reading it.

  5. Albert, thank you for this article!

    This article was especially moving to me, because as a kid I spent several months in New Zealand, including seeing all sorts of geothermal features. Our guide (also the pilot of the float plane) talked quite a bit about the lost Pink and White Terraces, and we did a flyover of the Tarawera site.

    For quite a few years, I’ve been trying to find out which travertine terrace we did see. I know it was on a lake, and had a dock (where the float plane tied up). I recall it being far less “rough” than Mammoth Hot Springs in Yellowstone, or other travertine sites I’ve seen – it was in many places far more the appearance of marble. I think
    orakei korako (Hidden Valley) might be it!

    As an aside, the Pink Terrace, at least, may have been found.
    https://www.waimangu.co.nz/about/blog/post/where-are-the-pink-and-white-terraces-now

    This makes sense to me, because it appear to me that the lake level is drastically higher due to having its old outflow blocked by the eruption (and it no longer has an outflow). My long-ago guide appears to have had it right; he said the terraces were likely covered with mud and then submerged, and so might be rediscovered and restored one day. I remember him pointing out the narrow strip of land between Lake Rotomahana and a bigger lake to the north, and saying that the bigger lake was over a hundred feet lower, so Rotomahana’s level could easily be dropped via a tunnel a few hundred feet long. He said he’d love to see the terraces restored, because they would be such wonderful tourist attraction, and also so that what he called “A dastardly example of wanton volcanic vandalism.” could be undone.

    • “A dastardly example of wanton volcanic vandalism.” That’s a stupid sentence of that guy. Volcanoes are nature. Vandalism is done by mankind. They can possibly restore them and have 10.000 tourists there per day. Afterwards they would collect the litter. And that’s vandalism. As far as we know volcanoes cannot think, but man can.

      • I’m pretty sure he wasn’t being serious.
        Its a modified version of irony, as a kiwi he may have english humour.
        Well, I smiled anyway…..

        • First people might not like volcanoes that much. They often thought that devils inhabited them. I didn’t think of him as a Maori.

      • Denaliwatch :I suspect this was an example of antipodean wit?
        CJ : Many thanks for anecdote, I imagine it must have made quite an impression on you

        • He did make quite an impression, a very good one. I’ll always remember that day. (we were with him all day). There was the fact I’d never been in a float plane before, plus seeing some geothermal wonders, but the guide himself made a strong impression as well, a very good one.

          I was 11, so I’m sure I was too dense to pick up on dry humor, therefor I have no clue whether his “dastardly example of wanton volcanic vandalism” comment was serious or not. I do know for a fact that I found the phrase memorable, hence why I can quote it after so long. I do think that, serious or not on that, he was serious regarding lamenting the loss of the terraces, because he said more than once how, if they were restored, it would be a wonderful thing for the people of the area, both for tourism, and to have them back. He’d mentioned that his grandfather had been to the terraces many times as a boy, and told him of them. He also said his grandfather had barely survived the eruption. (I’m not sure of my guide’s age, though I’d say he was well past 50, and this was in 1989).

          I do understand his decrying the destruction of the terraces; regardless of the cause, they were a natural wonder and important to the region. I felt that too while looking at that lake and the scenes of the eruptions; I wished I could have seen what once was. I felt the same when he talked about the giant geyser there; I wished I could have seen that as well. I can only imagine that the sense of loss must be far greater for those who are from there.

          • Wishes that come to mind:

            La Palma before 2021; The east rift zone before 1983; Spirit Lake before 1980; Plymouth before 1995; St. Pierre before 1902; Java/Sumatra before1883; The Bay of Naples before 79.A.D.; and on, and on, and on….

          • Was he Maori? The grandfather must have been very young (child) a century earlier. The Haszard family had two boys but I think both died.

          • Albert, he was Maori. He did say his name, though I’ve forgotten it; it’s been a lot of years. This was over 30 years ago, and he was past 50, maybe a lot past 50. I was 11, and awful at judging ages (I still am, just not as bad).

            I wish I could remember more of what he said, especially about the history of the areas. I don’t remember him saying anything more than his grandfather had barely survived the eruption, so I have no clue where his grandfather was (I’m assuming his grandfather lived in the area, due to having visited the terraces several times).

            Thanks again for your article, which has caused me to do much reminiscing about that long-ago visit.

          • I have not found a list of names of the Maori living at Te Wairoa. One name does appear: Sophia Hinerangi, one of the guides. Somne of her children would have been the right age.

          • @ Albert;

            If I’d taken notes and asked the right questions, we’d know the answer as to who the guide’s grandparents were, plus know more about what he’d learned of the eruption over the years.

            Sophia Hinerangi was the one who noticed the increased thermal activity, and she was a guide (same line of work) so my guess is, if she was my guide’s great grandmother, he’d have said. However, that’s only a guess.

            The more I think about it, I recall my father mentioning the buried village (we wee planning on seeing it on our own, a few days later) to the guide, and I don’t recall the guide saying anything. My guess is, if he had a personal connection to that particular village, he’d have remarked about it.

          • Yes, I expect you are right about Hinerangi. Given the likely age of the grand parent, there is one other option, namely that he would have been one of the children at Charles Haszard’s school. That school was for the Maori children. There were few survivors in the region other than at Te Wairoa. But it is guess work. It is really nice to hear about this connection to this event. It brings it even more to life. These stories lift it from history to reality.

          • Good point on Charles Haszard’s school. That would fit.

            My other guess was his grandfather may have been living somewhere close, though not as close as the destroyed villages. It would have still been very bad just survivable. I do wish I’d asked.

  6. Question: Anyone hear anything about Volcano in Italy being evaccuated due to unrest of the volcano Volcano?? Anyone? Anyone?

  7. This beautiful piece of history of a small Cotswold-like village and those attractive terraces reads like an introduction to more as this is a part of a monster, the Taupo Volcanic Zone, last eruption on White Island (Whakaari) 2019. Tarawera itself might be responsable für the Great Famine 1315-1317. So certainly one of the worlds most dangerous volcanic zones with a large caldera and presumably well studied in the US and compared with Yellowstone.

  8. Albert, you are saying the Maori could have known. After 500 years? Who knows who had been living there – you might tell us 😉
    Anyway, they didn’t have seismic measurements back then. To allow boats out to Whakaari after the earthquake two weeks before was a mistake though – they should have known.
    It will go on every now and then. Somewhere in the area.
    The heir of Chatham rise (Cretacious)?

    • Do not underestimate oral history. No TV, radio, phones and what do you do sat round a fire at night having consumed (insert appropriate intoxicant here)?
      You tell stories, and real ones probably embellished can go on indefinitely cut short only by writing.
      Its likely many early religious stories were originally real events, but well camouflaged. Personally (given widespread early flood stories from india to europe) I think both adam and eve and the flood derive from the flooding of the caspian sea circa 15kt BP. It would have been a relatively warm and benign region. I do wonder if this dispersal of what may have been a relatively advanced pastoral people (possibly primitive agriculture) kicked off the many proto-urban settlements from india to europe.

      • Oh, I’m not underestimating that point at all. But 500y is long. With the flood (Caspian or Red Sea) there might be testimony, Tempest Stele in Egypt and the Torah. Anyway certainly today they would know that the area is a classic of the Ring of Fire, Pacific Plate subducting, sort of the opposite that Carl sits on with his family. Less inhabited though which is better.

        • No. Absolutely no written testimony of the flood, all written down at the dawn of writing as already ancient oral history. Also 500 years from a major event affecting many families (and spread by marriages) isn’t that long. Even in my family I have a story about my great grandfather born 1823, nearly 200 years, and one of a great^n grandfather born 1588. With our dispersed families we forget that for most of humanity the core family and close relatives probably lived within a few miles of each other and reinforced the oral history round the fire.

          • One thing seems as sure as Amen to me: If Moses really guided the Israelites out of Egypt he was perfectly able to write, Aaron as well.

          • They are very recent, earliest proto-hebrew about 1000 BP.

  9. Just one comment.
    Pamukkale is travertine, that is calcium carbonate.
    Tarawera is silica, silicon dioxide.
    Very different, Pamukkale travertine is quite rapidly produced, indeed they have been making it more glorious by strategically diverting the flow down the hillside in new areas.
    Tarawere is silica (that’s what’s claimed) and clearly the deposits are produced very slowly indeed, judging by the rather small size of those currently seen (given temp, flow and time).
    Its what I would expect as silica is rather insoluble in water. Personally I wonder if the silica us not brought to the surface as alkali silicates (assuming a reasonably alkaline water) which then get precipitated with CO2 to deposit silica turning the silicates to carbonates. I just do not think the solubility of silica in water at sub 100C temp would be enough to produce anything in even millennial time periods.

  10. Thanks a lot for the article Albert. I enjoy articles with unusual geological phenomenons much.

    Here a picture of one of my lithophysae from iron rich rhyolite flows in south east Oregon/USA near McDermitt.
    This one is filled with (by hydrothermal activity deposited) chalcedony. The reddish colored flares in the chalcedony and the red in the shell a caused by iron minerals indeed.

    Upper beds, McDermitt. 8 cm.

      • It is not from the miocene McDermitt caldera (west of McDermitt) starting about 19 Ma ago.
        From the Calico Mountains, one of the last known flows, late miocene or even early Pliocene, about 5Ma.
        Well yes. Its old. 😁

    • Looks really bad .. I wonder How many bannanas and other crops thats been destroyed now, and burned fruits haves a terrible smell

      • “burned fruits haves a terrible smell”…

        Merely an echo of the true disaster.

        I recall the smell coming from Ground Zero for months after 9/11. I can speak to that personally.

  11. Thank you for a very good article Albert. And congratulations on the 10 year anniversary! Time flies… when reading such good a site. And I consider myself a frequent flier as in following VC. 😉

    As a mix of reading about effects of the base surge in the article and a comment on Taal in the comments section, I searched news of Taal last 24 hrs. and came across this article in the Inquirer on…. research on aftereffects from the last eruption. Highlighting base surge effects. A good read wo. any of the normal sun/daily mirror angles. Interresting.

    For those who might read it (and are more knowledgdeable than me) I have a question;

    The article states:

    “When Taal erupted, kilometerslong fissures appeared in the towns of Calaca, Lemery, San Nicolas, Agoncillo and Talisay. Some of these continue to widen to this day, entombing entire houses along their traces. ”

    Is this an aftereffect from the eruption or is it due to inflation still going on?

    Link: https://newsinfo.inquirer.net/1517771/proof-of-life-in-taals-wasteland

    All the best from Chios, Greece!

  12. It is not from the miocene McDermitt caldera (west of McDermitt) starting about 19 Ma ago.
    From the Calico Mountains, one of the last known flows, late miocene or even early Pliocene, about 5Ma.
    Well yes. Its old. 😁

  13. Jesper

    you have a discussion with Albert further up. Albert says that the magma comes from shallow depths, you contest this. Albert might be right depending on the meaning of shallow. Tonga Trench: Depth close to 11000 m, Kermadec further south: 10000 m, North Island, Hikurangi: Between 3000 and 3750 m.

    • I am not concentrated today. But what I got so far is that only the middle is rhyolite/dacite. The south and the north of TVZ including Whakaari is andesite. And there are also different slab mechanisms. So, what you have read might be about Lake Taupo and the southern part. Tarawera is completely different, and Albert might say more about it.
      Then there is relatively hot, hydrated mantle and dry, cold mantle, separated. So, it depends about which area you have read.

    • Then you have s.th. you like in the east on the ocean floor. That is the Hikurangi Plateau which was, together with the Ontong Java Plateau and the Chatham Rise a Large Igneous Province, maybe the largest known.
      That’s enough for my concentration today. It’s certainly interesting where some settlers built their Cotswold’s replica.

    • The magma was stored at shallow depth. It would not have formed there. The source of the magma is the subduction zone, but that may have been a long time before. Or just a few months: who knows. As Mike said, no telling what we would have seen with modern instrumentation. The scary thing is that we don’t know whether that would have given much of a warning. A VEI-5 with one hour of warning is frightening.

      • Yes. That seems to be the rule on that subduction zone.
        Also thinking of Mike Kearney, Raoul Island Eruption 2006. That’s further north though.

  14. Kilauea is starting to change again, the tilt at the summit is showing gradual deflation but the eruption is unaffected. It isnt showing on the main page at all for some reason, but every GPS station on the ERZ down at least to Pu’u O’o is abruptly rising now too, seems magma is moving into the ERZ. Might be a deep intrusion, and a slow slump event perhaps.

    • Ohoh… that sounds to me a little like what occurred in 2018. I hope that magma doesn’t get past the Pu’u O’o area this time.

      Chad, do you have any thoughts on the 1924 eruption? From what I’ve read, the explosive events were triggered by the lava lake draining away, much akin to 2018, though with one big difference; the lava in 1924 didn’t seem to emerge elsewhere. Where might it have gone? Seems interesting to me that if it went into the ERZ, it didn’t erupt.

      • 1924 could have erupted offshore, I know that is a proposed and dismissed theory but all of the Puna Ridge is deep, even only 1 km offshore of Cape Kumukahi it is 500 meters deep. 1924 collapse was also not that big, 0.2 km3 volume apparently, if there was more than 1 dike emplaced in the ERZ then 0.2 km3 could be spread out easily.

        • I hadn’t realized the lower volume of the 1924 magma, thanks!

          When, at the start of the 2018 eruptions, andesite was reported from one of the vents, I did wonder if it might have been from 1924. However, from what I heard, the chemistry pegged it as 1956 or so.

      • Should add that 2018 showed us one quite scary thing about caldera formation in Hawaii, it is a positive feedback loop. In Iceland or actually pretty much everywhere else, the big eruptions tend to decline gradually and begin fast. Hawaii the eruptions begin slower and accelerate until the caldera collapses to the level of where the dike started.

        Not actually sure if this applies to Mauna Loa though, it might behave more like the Icelandic eruptions, with a fast start. So this might really be a feature unique to Kilauea.

        • At Leilani, the initial eruption was slowed down by the older magma that had to be pushed out. It was more viscous and slow to react to the pressure from the new magma. That wasn’t the case at holuhraun where there was no old magma in the dike. Once Leilano got going with fresh magma, it evolved similarly to other eruptions. But that took some time

          • I am talking about after the new magma began to erupt actually, the eruption still accelerated to an abrupt end.

            Effusion rate in late July was as high as over 500 m3/s DRE or 2000m3/s bulk. The channel was built up over time giving an illusion that flow decreased, really the low levels were still very high just the walls grew so high only extreme surges could overtop. This was discovered in post by looking at drone footage taken over the duration of activity, the original estimates of channel depth were vastly underestimating. Most of the downdropped block in the caldera also fell late in the eruption.

            I think actually, the very last collapse and surge was the biggest of them all, with major overflows of most of the channel that expanded the flow field.

          • It is several years ago and memory can mislead. In my recollection, the cone activity had ben declining for some time before the end. It had become more episodic, where a collapse would push magma through but rather little happened otherwise. The end was not a surprise. But has anything been published on eruption rates in July and August?

          • https://link.springer.com/article/10.1007/s00445-021-01443-6

            Might be this, if not then there was definitely another recent paper that had the statistics and graphs.

            I recall that at the time the eruption was thought to be declining, but that was based on an assumption about the depth of the lava channel that turned out to be incorrect. The eruption did end in the predicted time but that might have been a bit of a lucky guess. Maybe effusion rate didnt really accelerate so much between June and August but it didnt decline the way Holuhraun did either.

            Seems effusion rate was closely tied to the magnitude of collapse. When the eruption began it was not even a draining event, entirely local intrusion and magma. It was not until the big quake and south flank slid down that the summit started draining. Early collapse was just conduit draining similar (nearly identical actually) to 1924. The collapses after May got bigger as an actual ring fault formed, and at the same time the eruption got more powerful and changed style from wandering vents to a fixed location.

  15. Confinement of San Borondón, Tazacorte and the disseminated one from El Cardón to Camino Los Palomares in the north.

  16. No idea. I can’t find the mechanism for its production.
    I may be missing something but silica (SiO2) is pretty insoluble although alkali silicates are quite soluble.
    Hmm, CaSiO3, is insoluble but Ca2SiO4 is a bit at 0.1%@20C oh, and is one of those chemicals with complex physical chemistry and all sorts of allotypes. I’ll bet this is what produces the silica when it cools and comes into contact with air. It would be nice to see a few actual mechanisms, but probably too complex to be worth studying.

  17. Now assume that finally the really deep stuff is erupting on the volcano (might have been that way for a month now).
    As such I consider it being hot enough to create true pahoehoe.
    If the volcano was generating true pahoehoe why does it always turn into A’a if flow rates are higher [citation needed] than some (low) threshold?

    Only one thing I could imagine for reason: Pahoehoe quickly cools off at the surface and creates those typical perpendicular micro “hoses” and structures. Since the flow is laminar, as I presume, it doesn’t intermix with the cold surface structures.
    A’a in the volcano’s example would have initially been pahoehoe when it, after having flown through the lava piping, comes to daylight, but due to higher flow rates the hot flow becomes turbulent and quickly mixes with the cold surface parts, bringing new hottest parts to the surface that in turn cool down rapidly.

    I think Jesper once suggested that this volcano’s lava should be runny enough to get pahoehoe but it wouldn’t work in the example.

    • The ground slope causes degassing and temp loss which increases the effective viscosity, which turns pahoehoe to aa. Also, the variations in volume over a period of time can rupture lava tubes, which create aa.

    • Hmmm thanks for your explanation. 🙂
      However, how would gentle slopes not (so fast) cool off and degas the lava as would steeper slopes?

      • Lava tubes form and can be maintained easier on gentle slopes. Look at Puu O Oo–lave which was tube-fed reached the top of the palis and immediately turned to aa at the bottom of the slope.

        Only after the tube became established further downhill did the flow remain tube-fed past the pali and onto the coastal plain, and remained pahoehoe throughout. This could conceivably happen at Cumbre Vieja, and to apply human attributes, it’s been *trying* to form a tube system.

        • Thank you for your sharing of knowledge, much appreciated.
          Looks like a plausible explanation 🙂

          One thing I also remember (in the end days of FAF actually), was that someone mentioned the word “shear stress” in terms of pahoehoe quickly turning into A’a, but I don’t know if I remember that correctly.

          • That’s deeper into chemistry than I’m familiar with discussing! 🙂 But I have read papers describing exactly that.

  18. On the other hand, what do we need to turn A’a back into pahoehoe?
    (Impossibly) reheating to 1500 °C or something like that?

    When we’re just at it, would 1800 °C pahoehoe turn into A’a only at much higher flow rates than 1150 °C (wasn’t that the threshold for pahoehoe in the first place 🙂 ) pahoehoe?

    • 1st paragraph: It’s possible, I guess, but you’d have to re-introduce gas into the lava–essentially turn it back to magma. You’d also have to dissolve every (or almost every) crystal that had formed during the transit from the mantle to the sample site.

      2nd: take a hike across Kilauea–the December 1974 lava (express train from the magma chamber) looks nothing like the November 1975 stuff (stored for some time), even though they’re both broadly tholeiitic basalt. Subtle changes in chemistry, temperature and flow rates, along with topography make all the difference.

    • Some fast channelized Aa lava flows can acually turn into pahoehoe If they reach flat ground and slow down.. providing the channel haves an insulating skinn ( this happens in Only the most fluid Hawaiian lavas )

      At 1800 C all lava woud flow like water almost .. white hot liquid
      But Thats Hadean Komatite territory

      • Hahaha was only a random example for the sake of clearly different numbers =D
        1800 °C should not be possible once more^^

      • Althrough the Hawaiian Hotspot is almost that hot
        But it cools on the way up

    • The burning fruits must smell awful
      A kind of sickly sweet smell. Banannas are mostly water, so they burn very slowly, still If inside the lava flow They probaly burn anyway If a hot enviroment is around them ..

    • Looks like fake news xD

      No, of course I made a joke, thank you for posting a video such rare! 🙂
      I just downloaded that since it is looking particularly spectacular!
      Wonder what the heck they (I guess it was geologists) were trying to measure there in the midst of the banana palm trees..??

    • I wonder if Taal is doing some low level throat clearing right now, after almost 2 years of unrest, I don’t think there the volcano has clear access to it’s magma because if it did I am sure it would be erupting by now/

        • I wouldn’t say it’s primed, rather unstable. Magma is pouring in and each and every day. In fact the longer it goes without a ‘proper’ eruption the worse it could be medium to long term. And there’s no telling that it couldn’t unzip right now, but I think it’s got a few months to go before anything at least and this strained frequent phreatomagmatic activity will be the status quo for the time being.

      • Probably. It has increasing heat, and some of that may be due to the hydrothermal circulation re-establishing after the previous eruption. But people should be careful. Taal can do what Tarawera did

    • The inner crater cone of Taal will prevent a major blast perhaps ..?
      Lots of gases are escaping the magma system, removing pressure
      Infact its a semi open conduit there

  19. Assume this volcano consists of a deep magma chamber with it’s top at 30 km and a shallow chamber with it’s bottom at 15 km.
    Both chambers are connected by a hose having the usual diameter in such a setting.

    How long will it take for the magma to rise from the lower chamber into the upper chamber? About 2 days?

    I don’t know if that’s the true setting, and I don’t care for the sake of the example.
    But some are suggesting that to be about the setting of that volcano.

  20. And on Mars Ingenuity continues its journey with flight 16 back towards the landing site then, all going well, to lead the way to the ancient river delta for Perseverance.

    NASA JPL @NASAJPL

    #MarsHelicopter continues to thrive! The mighty rotorcraft completed its 16th flight on the Red Planet last weekend, traveling 116 meters northeast for 109 seconds. It captured color images during the short hop, but those will come down in a later downlink.

    And as a bonus a new video of Ingenuity in flight filmed by Perseverance during flight 13.

    https://www.jpl.nasa.gov/news/nasas-perseverance-captures-challenging-flight-by-mars-helicopter

    NASA’s Perseverance Captures Challenging Flight by Mars Helicopter

    Recently downlinked imagery of a September flight has allowed the rover imaging team to put together a video of rotorcraft performing to near-perfection.

    Video footage from NASA’s Perseverance Mars rover of the Ingenuity Mars Helicopter’s 13th flight on Sept. 4 provides the most detailed look yet of the rotorcraft in action.

    Ingenuity is currently prepping for its 16th flight, scheduled to take place no earlier than Saturday, Nov. 20, but the 160.5-second Flight 13 stands out as one of Ingenuity’s most complicated. It involved flying into varied terrain within the “Séítah” geological feature and taking images of an outcrop from multiple angles for the rover team. Acquired from an altitude of 26 feet (8 meters), the images complement those collected during Flight 12, providing valuable insight for Perseverance scientists and rover drivers.

    Captured by the rover’s two-camera Mastcam-Z, one video clip of Flight 13 shows a majority of the 4-pound (1.8-kilogram) rotorcraft’s flight profile. The other provides a closeup of takeoff and landing, which was acquired as part of a science observation intended to measure the dust plumes generated by the helicopter.

  21. Great post Albert, never heard about it before and fascinating informative post
    Thanks

  22. Tallis

    I just read this excellent piece of your’s that I’d like to add an idea to, not mine though:
    https://www.volcanocafe.org/eruptions-of-basalt-and-rhyolite/
    Concerning the Permian-Triassic extinction In Dorrik Stow’s book about the Tethys Ocean he writes: “The consequences (of the construction of Pangaea) were manifold, although the process was very slow. Sea level fell to an all-time low, its lowest point in the whole 542 million years of the Phanerozoic era. It was around 250 metres – meters 😉 lower than at the beginning of the Permian period…..The seas simply rolled back from the land until only 13% of the continental shelf areas were submerged, thereby greatly reducing habitat diversity (most life was marine) and promoting ecological instability. Shallow shelf seas are regarded ecologically as the nurseries and hothouses of the ocean world……A further important result of lowered sea level was the exposure of many of the peat-rich deltas and swamplands that were a legacy of the great Carboniferous and Permian forest.”
    This then, he says, released large amounts of carbon dioxide into the atmosphere and also into the ocean waters which, he thinks, led to inevitable global warming and a change in the ocean chemistry. The Siberien Traps adding to this might have caused a “nuclear winter”, albeit shorter, but then added with their gasses to global warming, a poisoning of the atmosphere and acidification of the oceans where most of the life was concentrated.
    Geologist and Oceanographer in Edinburgh Uni, I believe emeritus now, who was also specialized in marine paleontology.

    I thought this might interest you concerning the temperature at the end of the Perm. I at least got an idea.
    I also get the impression that there were mostly two processes, the same 66 Ma.
    Very good piece of yours which I basically read because of Rhyolite.

    • All major flood basalts are acossiated with global warming too, they release insane ammounts of CO2 over short geological timescales, We humans civilization release as much as CAMP did perhaps even more.

      Its true that the start of a LIP maybe acossiated with cooling indeed because of the massive sulfur injections.

      But in the end the atmosphere fills up with Carbon Dioxide. Siberan Traps and CAMP had both short lived But extreme global warming events. This cannot be denied because its in the geological data.

      • What is short-lived then? Everybody who reads geology, volcanism and esp. astrophysics – or teaches them for that matter 😉 has two timescales, one for deep time. So, this is difficult. It is estimated from fossils that the extinction period went on for 8 million to 10 million years. That’s a rather long thing and a sign for a permanent climatic change with new plants and new species who were better adapted. The Sib. Traps are supposed to have lasted for less than 1 million years.
        S.th. interesting though: Greenland’s fossils show a more rapid extinction (80 000 years). I’ll try to find out whether Greenland was the neighbour of the Sib. Traps back then.

      • Denaliwatch

        Chixlulub was a geological instant event: most of the damage was done in a day
        And the extinction by impact winter probaly Only a few took years. A major asteorid impact is in a geological instant! and very diffrent from even Volcanism or climate changes

        Whole continental interiors was burned down in hours during that Impact

        • I know. But this was about the Permian Extinction and some additional information for Tallis/Albert whose article I appreciated. Not that much similarity to 66Ma and more devastating wiithout a meteorite impact as far as science knows.

  23. The terrfying scale of the Chixlulub impact event. That woud have been an Impressive sight for soure. Most of the damage comes from the ejecta that later reenters the atmosphere heating up the entire atmosphere.
    Lots of atmospheric heating with so much stuff moving through and falling into the atmosphere at souch speeds

    This really makes any VEI8 eruption look like a fart 🙂

    Asteorid impacts kinetic energy is equal to almost 300 million tsar bombas is the impact worth. The crater is filled by a 200 km wide and 10 km deep impact melt sheet. Many many tens of thousands of km3 of Earths crust was vaporized.. anyway Volcanocafe stores old comments, they are never overwritten.. You can always find them

    https://phys.org/news/2020-03-simulation-evenly-earth-chicxulub-asteroid.html#lightbox

    • Chad have you seen this? Crazy stuff
      Not strange that North America became totaly incenirated by this ejecta kinetic heating. It woud be an INSANE sight to go back in time and see Chixlulub. I give you the task to draw Chicxulub in paint as it woud have looked like from Cuba one minute after impact.

      Any volcanic eruption is small fish compared To this of course.

      • Dont know if you would really see anything, the flash would look like a star but much brighter. Cuba also is not really that close, the Earth isn’t a flat surface so the fireball would not be visible as far as you think. I don’t know if Cuba was even there in the Cretaceous.

        • No. Good point. Cuba wasn’t there (probably), and the Caribbean Plate is assumed further west.

      • The really insane stuff is hours.. after when the ejecta reenters Earths atmosphere
        Thats alot of atmospheric heating, trillions of meteors fills the skies, transforming Earths skies into an oven.
        The whole biosphere in the northen hemisphere was probaly burning.

        This explains why the large crocodilians mysterusly surivived that, because coud shelter in water bodies. Thats why They surivived.. the ejecta heating

        Perhaps only Antartica was relativly untoutched by the Chixlulub Tephra Reentery heatwave

        Dinosaurs most of them was probaly warm blooded, and that haves a high food demand, so They perished during the impact winter, while cold blooded crocodilians surivived

      • Infact the large semi aquatic crocodiles, was one of the few very large animals to surivive Chicxulub. They are cold blooded and dont need to eat often: makes it easy for them to surivive an Asteorid Winter

        They coud shelter in ponds and lakes – rivers and avoid the searing surface temperatures during the Reentering ejecta

        The land dinosaurs where both incenirated and starved

      • But the boiling ejecta plume and ejecta curtains woud have been very visible minutes after impact .. that stuff coud have been as hot as 27 000 C making you blind instantly. It woud fan over North America and begin to reentry

        The Impact Plume rised to many thousands of kilometers in height hours after impact, full of condensing rock vapour and glass droplets

        I guess in Gulf Coast the entire sky woud look like an kiln oven .. terrfying perhaps even white hot

      • Woud a fictional Tsar Bomba with same energy as Chixlulub be as destructive as the real asteorid thing?

        Perhaps there woud not be an ejecta storm..

        I can just imagine the mushroom cloud ..

        But a hydrogen bomb that Big will not do a mushroom cloud, the atmosphere is too thin for that on that scale. Tsar Bombs fireball was 10 km wide

    • Never underestimate the Chicxlulub blast, even the atmospheric entry, that lasted just a few seconds even at shallow angle, produced a fireball that woud make the 2013 russia meteor look like childerns play. It woud kill millions the Chicxlulub boilde if it came into the atmosphere over a densely populated continent, from its own thermal radiation.

      The asteorid itself was around 14 kilometers wide, and may have gotten in at 35 to 45 kilometers a second.

      And thats the atmospheric entry, the blast is much much much worse.

      Im also fascinated by the ionized plasma and vapour trails that all reentering objects Leave behind, man made or natural

      But perhaps better to discuss this in the VC bar

      • This happens extremely rarely, and NASA is working on it. Which is something I consider sensible.

  24. Latest 12-day InSar of Mauna Loa from ASF. No expert, but this looks ominous, given how much weight must be pushing in the opposite direction.

    • Yesterday I happened to google earth both Hawaii and Pa Palma and was struck bu the similarity of shape (teardrop) with a big old volcano to the north and an eruptive fissure of long standing trailing to the south. Very similar shapes, I have no idea why I didn’t notice this months ago.

      • The jet stream a few thousand miles either side of the atlantic looks very odd, too.

      • You wrote Hawai’i and then must have been thinking Pahoehoe, so you got Pa Palma 🙂

      • As you are interested in the deluge. There are many of them, and here and interesting passgae for friends of Toba and of the history of Homo sapiens leaving the rift zone: “The Lake Toba event, approximately between 69,000 and 77,000 years ago, caused a massive drop in sea levels, exposing the barrier and enabling modern Homo sapiens to leave Africa via a route other than Sinai.”
        https://en.wikipedia.org/wiki/Outburst_flood

        • Toba is blamed for many things. Even the ice age. In reality, there is little evidence for that. The ice age was already under way and got worse, but that happened in all ice ages. Single eruptions tend to have fairly short effects, up to a decade, because the sulphate drops out of the stratosphere within a few years. Toba is also blamed for a genetic bottle neck in humanity, but this also has little evidence and of course directly contradicts the claim that it allowed humanity to leave Africa. Modern people were living in India and Southeast Asia at the time, and may even have reached Australia. The population in India was particularly badly affected by Toba because much of the ash ended up there. But archaeology shows that the culture there before and after was very similar, so they did survive.

          • The Yemen route was never entirely dry and would have required sea faring ability. The Yemen barrier was smallest around 65k ago (i.e. 10 thousand years after Toba). The northern Sinai route was feasible much earlier. There was a major migration out of Africa around 65k but people were spreading into Asia before, possibly by 80k.

          • Considering even the most primitive humans on the planet that were stone age until recent times all had quite effective water faring techniques I am totally baffled as to why anyone considers a land bridge as essential.
            The reasons why one might risk s longish passage can be anything from evading vengeance, evading slavery, needing a new patch of land to exploit, blown by storms, to crazy eddie, and they had a VERY long time to do it.
            Certainly anything visible from a high point across a strait would suffice.

          • Definitely. People made it to Australia very early on, by island hopping. The Yemen red see barrier was surmountable. The climate might have been more of a problem. People do need fresh water. Rainfall varied over time

        • I cannot agree with the Wikipedia entry. Not only does it lack any reference, the effect of even one large volcano in no way can affect global sea levels. Given how much water there is on this planet, a small explosion on the world’s surface is a pinprick compared to it.

          Toba was no doubt a devastating event for the area. But rises and falls of global sea levels can only result from the ice cycles caused by orbital variations.

          Unless, of course, someone pulls the plug out.

    • The cenozoic Ice Age haves To do with the ever dropping CO2 levels since Eocene. The Atmospheric CO2 have crashed totaly Since meozoic. In the late Eocenes it dropped below 750 PPM and Antartica glaciated, that caused a huge drying of the planet.

      The drop of CO2 haves To do with rainfall sillicate weathering from orogenic mountain building,colder more productive oceans and volcanic outgassing not being as vigorous as before

    • “FUUUUUUUUUUU… I made a sign error in the math!! =(
      But no other could find it since the math was so overwhelmingly complicated.

      Alas, now this asteroid’s harmless trajectory became into a dangerous trajectory due to the deflecting attempt 😉
      But I hope it won’t do too much of damage ;)”

      Well, unlikely for now, but might happen with further, more serious attempts^^

      • No, why. This will happen in Sept. 2022, and I believe that NASA did some Maths as well.

      • Wouldn’t matter, its in orbit round a bigger asteroid and the satellite is so pifflingly low in total energy they are hoping they might just detect a small orbital change.
        Damn smart these scientists, they think of stuff….

        • Yes, they are smart. It’s an experiment. If they are lucky they can figure out what to do with a bigger one. They target the moonlet, and with results they might target the main asteroid or another one. In 100 years they would know what to do.

          • The reason they are going for the moonlet is be able to see the effect. The change is too small to detect for normal asteroids. But the orbit allows one to see a minute change in the period of the orbit.

          • I just looked at the colonization of New Zealand. The earliest dates are for 1280 (1250-1300), but more points to after Tarawera’s first explosion in historical terms, which makes sense as they might not have enough to eat on the Pacific Islands after the eruption. Yet, even 1280 would mean that there weren’t too many and they might have all died.

          • And thank you for the more detailed explanation. I roughly got it, but wasn’t able, obviously, to explain it precisely.

      • Thanks for your explanation. My example was a bit on the joky side =)
        Moreover, I thought they would be looking for a more direct effect.

  25. Spectacular article, Albert! The Tarawera eruption is perhaps the most fascinating to me of all the historic eruptions. I love the geologic oddity of basaltic plinian eruptions, and the unique elements of this eruption really spark the imagination.

    I couldn’t have asked for a more interesting article, thank you Albert!

    • Indeed Basaltic Plinian eruptions are one of my favorite style of activity, really Impressive sight they are. They produce the largest lava fountains among mafic eruptions.

      But Sillica rich plinian eruptions are also just another more explosive form of lava fountaining. Calbuco 2015 produced fantastic pumice fountains.
      But sillicous magmas haves more violent fragmentation as their viscosities wont allow gas bubbles to escape easly

      • Calbuco was not silicic, andesite and basaltic andesite. The eruption was glowing so probably the magma was not that viscous, somewhere around 1000 C which we have seen is enough for andesite to flow freely if slowly.

        • Right: “The highly hydrated magmas that characterize the volcano’s petrology increase its potential to generate explosive eruptions. The main hazards are associated with the volcano, however, there are the evidences of lahars and block and ash flows, mainly directed towards the fans to the Northeast, South and Southeast, in areas with growing population and infrastructure development (Selles and Moreno 2011). In April 2015, the last volcanic eruption of the Calbuco was recorded. According to studies such as Castruccio et al. (2016), the erupted products were mainly basaltic andesites.”
          https://earth-planets-space.springeropen.com/articles/10.1186/s40623-020-01332-w

  26. Something’s up at Grímsvötn (from https://twitter.com/gislio/status/1463540652118102018)
    “Potential glacial outburst starting in #Grimsvotn based on icecap dropping suddenly according to instruments say scientists at
    @Vedurstofan
    . Some outbursts there lead to #volcanic #eruptions but no evidence either way. Last eruption was in 2011. #Iceland”

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