Volcanoes can erupt invisibly. A sudden, swift explosion in an isolated location may be unobserved and still have worldwide impacts. The source of the large eruption of 1809 remains unknown. We still don’t know the culprits of the volcanic climate catastrophe of 536 and 540. The link between the year without summer of 1816 and the Tambora eruption was made only in the 20th century. The events of 43BC have recently been assigned to the Okmok volcano – who had expected that? The Hunga Tonga eruption could have been missed even just 50 years ago, leaving us to wonder where all that stratospheric water was coming from. Was Hunga Tonga the cause of the exceptional weather last year? We may never know – it is hard to know what part of the climate is volcanic and what part is our very own global heating. But it seems eminently plausible.
Even the largest eruptions may be invisible. We see the impacts but miss the source. The largest eruption of the past millennium was in 1257; it was a mystery until very recently when it was shown to have come from an unexpected volcano, Samalas in Indonesia.
The second largest (possibly) eruption of the millennium, in the 1450’s, is a particular enigma. It has turned into a major dispute: the cause, the effects and the date have all been questioned. Science does not always give us certainty – it can also question what we thought we knew. But volcanoes will not be denied. This is their story.
The calendar was uncommonly complicated. It was based on a 52-year cycle where each year was given both a number and a name. There were four names and the numbering went up to 13, so that (a bit like a pack of cards) the calendar could distinguish 52 years. The four names were Rabbit, Reed, Flint Knife, and House. The year ‘1 Rabbit’ would be followed by ‘2 Reed’ and so on up to 13 Rabbit. After these 13 years the numbering went back to the beginning, so that the following year would be 1 Reed. This allowed for 4 counting periods or 52 years, after which there would again be a year 1 Rabbit. It sounds remarkably similar to the calendric complexity in Jostein Gaarders’ book ‘The Solitaire Mystery’. The book delves every deeper into the cycles of time in order to reconnect a broken family – using a pack of cards and a joker. It is so easy to get lost in time.
“What do you learn in school, Hans Thomas?” Dad asked. “To sit still,” I replied. “It’s so difficult that we spend many years learning to do it.” (The Solitaire Mystery)
This particular year ‘1 Rabbit’ ran (probably) from January 24, 1454 to January 23, 1455. It was a bad time. Over a period of several years, bad weather and frost had devastated the harvest; food supplies had dwindled and finally ran out. The worst crisis the empire had ever experienced was to become known as the famine of 1 Rabbit.
At the time, the empire ruled the Valley of Mexico. In spite of the name, the Valley of Mexico is a highland plateau, more than 2 km high, located in the centre of Mexico. It is surrounded on all sides by mountain ranges, part of the Trans-Mexican Volcanic Belt. There is no drainage out of the valley. Water running down from the high mountains collected in the Valley in several large lakes. The lowest lake, Texcoco, was the end point of the flow and it was salty. The other lakes provided fresh water , though it could also become saline at times. With a mild, equitable climate, a water supply and a fertile soil, the population exploded. At the time of this 1 Rabbit, a million people lived here. Much later, the lakes were drained and the entire Valley was metropolised. It is now the location of Mexico City, one of the largest cities in the world. I was there once, at a time when there was still extensive damage visible from a major earthquake. The earthquake waves had been amplified by the dry lake bed and this had increased the damage. Nature is not easily denied. The early-morning views of the mountains around Mexico City were magnificent. But soon the pollution would rise and the morning views disappear.
Famine in the Triple Empire
The Valley of Mexico was the heart of the fearful Aztec empire. The empire was build on an alliance of three of the peoples living in the region: Tenochtitlan (who eventually would become dominant), Tetzcoco, and Tlacopan, each of whom had settled around one of the various lakes. The alliance was not all powerful: there were nearby nations who managed to maintain their independence, leading to the almost ritualised warfare of the War of the Flowers. Why does paradise so often brings out the worst in people? Perhaps it takes Rainbow Fizz, the sensory drink of the Solitaire Mystery, to survive paradise.
The stories report that the problems started with early frosts, perhaps 3 years before the famine. In the Valley of Mexico, crops are planted in late spring, to make use of the summer rains. Harvest is in November or December. Frost can happen here on occasion: it is not common but temperatures can drop a few degrees below freezing during the winter months. An early frost could badly damage a late harvest. The famine began with such an early frost, so unusual that it killed not only the corn and the plants but also the trees. This happened two years in succession. The frost occurred everywhere above 2 km altitude which covers the entire Valley. Two years of summer drought worsened the situation. In the reports (compiled much later by the Spanish invaders), these two events follow one another, but it seems not unlikely that the drought and early frost were related and happened in overlapping years. The famine was caused by a few years of quite unusual weather.
Food became scarce. For a while people managed from stored food. Once this was gone, they scavenged for wild foods: roots, cactus leafs and the green of corn plants. But these carried little nutrition and people started dying. The three Aztec kings opened up the royal food storages but these too ran out. Now the kings gave permission for the people to leave. From the stories, it appears that the famine covered all lands above 1 km altitude: food was still available in the tierra caliente, the lower lying land at the coast. Many went to these low-lying region around the Gulf of Mexico where they sold their children in return for food. (They could retrieve the children later if they paid for the food those children had consumed.)
This famine was exceptional for the region. Famines are more common in regions with a shorter growing season, which can be badly affected by a period of poor weather. This is one reason they were regular in medieval Europe. With little buffer against bad times, hunger could set in quickly. The Valley’s longer season was more resilient against poor weather, and agriculture was sufficient reliable that a one-year store of food was achievable and provided a sufficient buffer in normal circumstances. But these were not normal times.
The precise sequence of events is open to discussion. The reports claim four years of famine, two with frost and two with drought. But the descriptions show some repetition which suggest there may have been some overlap. The climate upheaval may therefore have lasted 2, 3 or 4 years. The famine ended after the New Fire ceremony which was held at the beginning of the new fifty-two-year Calendar cycle. This was at the beginning of 2 Reed. That would have been in 1455.
The Aztec empire learned lessons from this disaster. They expanded their rule to cover Mexico all the way to the coast. This expansion brought the people who had left for the tierra caliente back into the fold. But it did not provide more food resources for the Valley: travel was too slow and hard (in the absence of either the wheel or horses) and the carriers would have needed more food for themselves than they could carry. The central cities therefore remained dependent on their own agriculture. The management of the lakes was improved to ensure adequate supply of fresh water. That was done by building dikes to stop back flow from the lowest, salty lake. That allowed for longer periods of irrigation.
The famine and population movement had an unintended consequence: there was now a shortage of victims for the required ritual human sacrifices. That was solved in an innovative way. There were three small, independent kingdoms near the Valley of Mexico: Tlaxcala, Huexotzinco, and Cholula, located in the Tlaxcala-Pueblan Valley. In spite of its overwhelming size, the Aztec empire never conquered these close neighbours. Even the Spanish were surprised by this. From the mid 1450’s the Aztec alliance battled against these independent kingdoms in the Wars of the Flowers. The battles were indecisive and it appears the Tlaxaca were often given advance warning of where the Aztec would approach. When the Spanish asked Muteczuma, why, having those enemies surrounded, they did not finish them off once and for all, the reply was: “We could easily do so; but then there would remain nowhere for the young men to train, except far from here; and, also, we wanted there to always be people to sacrifice to our gods.” The wars provided the human victims. The situation was complicated with the independent kingdoms often working with other enemies of the Aztecs, but there were also long periods of truce where the opposing kings would visit each other for feasts. This situation lasted for the entire period from the end of the famine of 1 Rabbit to the arrival of the Spanish. At that time, the Tlaxcala, clearly not happy with the situation, asked the Spanish the help them. They provided twenty thousand soldiers for the Spanish siege of Tenochtitlin which ended the Aztec empire.
The world beyond
The famine of 1 Rabbit did not stand on its own. Other places in the world also had problems with the climate. In China, the spring of 1453 was plagued by snow which came so late that it damaged the crops. The following winter was very cold with part of the Yellow Sea reportedly frozen.
Tree rings in the UK and in North America were narrow in 1453 and 1454. Frost damage was seen in Californian alpine bristlecone pine trees. These trees are particularly well suited to finding frost damage in annual rings during the growing season. Sometimes the event that caused it can even be dated precisely. For instance, frost damage in rings that formed in 1884, seen in numerous trees, happened on a very cold night 9-10 September. The summer of 1884 had been cold, delaying the growing season. In normal years the growth would already have been completed by the start of autumn, making the rings frost-proof. In cold years growth would be delayed into autumn, and this made the rings more susceptible to damage by an early frost, which happened in 1884. Significant frost damage was found in tree rings from 1453.
Climate on the rocks
Past climates are also recorded in the glaciers of Greenland and Antarctica. The snow incorporates pollutants in the air. One of these pollutants is sulphate, which is emitted by volcanoes. A large eruption can cause a notable increase in the sulphate concentrations. The ice forms from the seasonal snowfall, and this leaves recognizable annual layers in the ice. Count the layers, and it is possible to find out which year (and on occasion which month) the eruption occurred. The counting of ice layers has become more accurate over the years.
For the period around the famine of 1 Rabbit, there is indeed a significant sulphate layer in the ice, both in Antarctica and in Greenland. The layer counting has not always been easy, though. In Antarctica the peak was found in seven different ice cores, but not always counted to the same year. In some cores the year was counted around 1453-1455, others gave 1450 or even 1460. The problem is that every core can suffer from counting errors (a layer may be missed if little or no snow fell that year, or a large snow event may look like a double year). The counting may also have started from the wrong year. The layers only become recognizable after some decades when the snow becomes compressed by the overlying layers: this makes it hard to know when to start the count. This is solved by counting from a known event, often the 1258/9 sulphate peak, but not all cores include this. Sometimes the counting was started from the 1453 peak itself, assuming that was the right year. That is fine if it happens to be right, but gives false assurance if the wrong date was used! Greenland also had problems. There were several sulphate peaks in the ice, a few years apart: it wasn’t entirely clear which peak (if any) coincided with 1 Rabbit.
Plummer in 2012 (https://cp.copernicus.org/articles/8/1929/2012/cp-8-1929-2012.pdf) re-dated one of the Antarctic ice cores and found that the eruption occurred in 1458. This date agreed with some of the results from Greenland. The sulphate amount in their core was almost twice as large as that of Tambora! They found indications for two eruptions, with the main one around 1458 and a smaller one in 1453.
This did not fit well with the tree ring data which showed a strong effect only around 1453. Cole-Dai in 2013 (https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/jgrd.50587) looked in more detail, and found strong evidence for the two eruptions, where the 1453 one was only seen well in Greenland and was therefore a northern volcano, while the much larger 1458 eruption was seen in both hemispheres but stronger in Antarctica and therefore likely came from the southern tropics.
Sigl et al in 2015 (https://www.nature.com/articles/nature14565.pdf) clarified the discussions but ended up muddying the waters. They found that the older Greenland ice cores (older than 1257) had been misdated by up to 5 years. This shifted the Eldgja eruption from 934 to 939, the currently accepted year. But this change did not affect the younger dates where the two eruptions remained at 1453 and 1458. The former was seen mainly in Greenland and therefore came from a northern eruption while the 1458 eruption was tropical. They found that the 1458 eruption was the second largest in the past 2000 years, after Samalas (1257) but ahead of Tambora (1815), based on the sulphate deposition. The 1453 (northern) eruption was much smaller. They ranked it’s climate effect as the 4th worse among the known eruptions of the past 2500 years– but this climate impact was dated in their paper to 1453, not 1459 (the climate is worst a year after a major eruption). There seemed a major disconnect here between the eruption and its impact.
A later paper confirmed the importance of the 1458 eruption. Gautier et al in 2019 (https://www.nature.com/articles/s41467-019-08357-0) showed that sulphur isotopes can be used to distinguish stratospheric from tropospheric eruptions. The 1458 peak in Antarctica had the third highest stratospheric signature in the last 2000 years, twice as strong as Tambora. This really appeared to have been a very large explosive eruption.
The climate excursion was initially thought to have been caused by an eruption from Kelud in Indonesia. In the early 1990’s several papers pointed out that it could instead fit the eruption from Kuwae, in Vanuatu in the southern Pacific, which had been carbon dated to between 1420 and 1460. Kuwae’s location would fit quite nicely with the indications for an eruption in the southern tropics.
Kuwae is invisible. It is known only from oral histories in the region. It is the Atlantis of the South Pacific, a non-existing place, an island that had sunk amidst destruction. The local people still know where it was, in a gap between the islands of Epi and Tongoa. The oral stories contain details such as where each of the villages had been within this gap, and how they were destroyed when the land exploded.
In the 1890’s, Kuwae was recognized as a submarine caldera. The dark line on the map indicates the caldera rim. The coast line of each island facing the caldera consists of steep cliffs, part of this caldera rim. And if there was any doubt about the volcanic nature of the hole, there is still some activity (basaltic) within the 10-km wide caldera.
The local oral histories talk about the eruption The stories list 30 generations of chiefs before the eruption: the eruption which occurred in the middle of their history. A layer of burned trees and human-made artifacts underneath the ash shows that indeed, this was a green and populated land before the eruption.
The eruption split the island and forced the surviving people to flee to Efate where the refugees caused conflicts. The stories tell that the eruption came unexpectedly. There had been no history of volcanic eruptions at this location. (In fact, although the local islands here have a volcanic basement, much of the coast consists of raised coral reefs.) A large tsunami is mentioned, but the oral history puts the tsunamis and earthquakes before the main eruption. The eruption may initially have started on a submarine flank.
The bottom of the Kuwae caldera is around 400 meters below sea level. Originally it had been much deeper: there is as much as 380 meters of tuff at the bottom of the caldera. (A new volcano has also grown there). The coastal cliffs expose tephra which is 120 meters thick, consisting of several layers. The layering shows how the eruption proceeded. The first part was a longer-lasting maar-like eruption, where magma interacted with water. This was followed by the explosive ignimbrite event which led to the caldera collapse. As the eruption progressed the ejecta became dry: in the battle of magma against water, the magma won. Several vents were active, including some outside the caldera.
The layers indicate that it was a fast eruption: there is no evidence of any weathering in between layers. It may have lasted hours, days, or perhaps a week. During the eruption the magma evolved from basaltic andesite to dacite (the majority) . The current submarine vent in Kuwae is back to basaltic andesite.
Afterwards, Tongoa’s devastation was total. The island was covered under meters of ash. Over time vegetation and animals returned, but there were exceptions: unique in the archipelago, Tongoa was left without snakes! Grass dominated the vegetation for a while, until the trees re-established themselves. Recovery even from a major volcanic eruption can be fast in a wet, tropical climate. But it took more than 200 years before the new forest had stabilised.
A few human survivors returned to southern Tongoa only 6 years after the eruption. But northern Tongoa, closest to Kuwae, was resettled only generations later – so long after that these new settlers brought a different language with them. There are still two different languages spoken in north and south Tongoa!
This was a large eruption, as already shown by the fact that the caldera is 10 km in size. The oral histories state that there had been a cone before the eruption. The volume of the caldera, assuming a large cone, is estimated at 35 km3. That is sufficient for a VEI-7 if it was all ejected explosively.
Carbon dating put the eruption somewhere around 1420 to 1460. The Kuwae eruption has been blamed for a sharp decline in trade in the Pacific at that time, and for a major tsunami in New Zealand. We can now add to this the climate shock of 1453 with a large global temperature drop of around 1C. And of course there was the sulphate in the ice, used to be put a precise date on the eruption, on the assumption that Kuwae was indeed the source of this sulphate.
But there are problems with this interpretation. One may wonder why there were survivors at all. No other VEI-7 or large VEI-6 has left us with a local oral history, not Samalas nor Tambora. The reason is a lack of survivors: for Tambora, there were no survivors within 20 km and the local culture was wiped out. This lack of oral histories is true even for Eldgja. (We know for Laki how precarious local survival was, and how dependent on help from outside which would have been lacking at the time of Eldgja.) But for Kuwae, people managed to flee who had seen the eruption itself. The ash layers on the more distant islands are not as thick as might be expected. Resettlement within 6 years also suggests that the southern parts of Tongoa were not as badly hit, although the fact that the settlers stayed away from northern Tongoa for generations shows how bad the devastation was there.
It has been suggested that the caldera had formed in several smaller eruptions. But this is not what the oral tradition reports, nor is it consistent with the layering seen in the caldera walls. The presence of survivors could be due to the initial maar-like eruption, which could have given people cause to flee before the major explosion. Coastal eruptions can put much of the ash into the sea, if the wind is right. But the size of the Kuwae eruption and its association with the sulphate ice layer have been questioned. We don’t know.
We are left with problems. The major eruption is dated to 5 years after the associated climate havoc, and the identified culprit is in some doubt. We have an eruption in search of a volcano, and a climate excursion in search of an eruption!
Evidence from the ice
As we have seen, the ice indicates there were two eruptions. The first one was in 1453, and affected the northern hemisphere only. The second one was worldwide and therefore tropical, albeit with higher deposits in Antarctica which suggests it came from the southern tropics. This second eruption was a major one.
Hartman, in 2019, (https://www.nature.com/articles/s41598-019-50939-x) took the bait. They went through the Antarctic ice core with a microscope to find tephra: particles from the eruption which had managed to get this far, blown by the wind. It is called cryptotephra. It is only seen for very large or local eruptions. Hartman et al search a 10-cm thick section of the ice core. Five particles were found, roughly 10 micron in size.
The composition of these grains did not agree particularly well with Kuwae. The particles were rhyolitic with 75% SiO2 while Kuwae grains were typically in the 60-70% range. The sodium fraction was also a little higher than that of Kuwae. The composition is similar to that of Kaharoa (New Zealand) or Reclus (at the southern tip of Chile). Kaharoa can be ruled out as New Zealand did not have a major eruption around this time. They argue that the tephra has to come from a volcano near Antarctica because tephra does not travel far. The paper therefore argues for Reclus.
Reclus’ eruption history is not well known, but it has had several rhyolitic explosion. However, it is too far south for the Greenland ice signal. The paper therefore argues that there were two eruptions in the same year, one near Antarctic and one in the north. This disagrees though with the isotopic evidence that the sulphate came from a major stratospheric eruption.
The grains can not have come from Kuwae, and so there must have been another eruption. But whether these grains are from the same eruption as the sulphate remains an open question.
There is another way to date eruptions, using coral. Coral gets its carbonate from sea water. This includes the oxygen and carbon isotopes in the sea water and these isotopes can be affected by eruptions. Coral grows slowly, and a particular layer can be dated. Abram in 2020 (https://www.nature.com/articles/s41586-020-2084-4) analyzed corals from the Indian ocean south of Sumatra. A clear 13C spike was found in the coral. A similar spike occurred after Tambora, confirming a potential volcanic cause. The coral was dated using uranium and thorium decay to around 1452. They attributed this spike to Kuwae. The year disagrees with the ice core dates which put it at 1458. The later date might still be possible for the coral but at low probability.
The most reliable record of climate in prehistory comes from tree rings. Counting the rings gives the precise year, and measuring the width of the annual ring gives the growing quality of the year. A thin ring can come from a cold or dry year. Frost damage indicates that the growth in summer was so slow that it still continued into late autumn, and/or that frost came early. The best trees to use are from higher altitudes, where the growing season is shorter and which are most affected by any temperature variations: their rings show the clearest signal.
The evidence for poor tree growth in the 1450’s was already well established. The case was revisited in 2017 by Esper (https://link.springer.com/article/10.1007/s00445-017-1125-9), who collated a record from 18 different sites across the northern hemisphere. Not every location was equally affected. The strongest signals came from higher latitudes in Europe and Asia, and from the northwest of north America with the exception of one record from British Columbia which showed warming when all other records showed cooling. In the coldest year, summer temperatures were down by −0.4°C in the Swiss Alps to a staggering −6.9°C in the northern region of the Ural mountains.
There are two different ways of studying the tree rings. The one already mentioned is the so-called TRW method, where TRW stands for ‘tree ring width’ (science is very good at obscuring the obvious). The second method is called ‘MXD’: this stands for ‘maximum latewood density’ and refers to the thickest cell wall within a tree ring, measured using X-ray. It appears that the TRW is good at measuring effects over several years, since it depends in part on the health of a tree and this can be affected by previous years. The slow recovery of the tree from a volcanic eruption can be captured well. But for the sudden response to an eruption, the MXD method is found to be better. It very clearly shows the onset of the cool conditions.
Neither method is sensitive to winter temperatures: tree rings cannot show whether a winter is cold or mild. But in fact winter temperatures are less affected by volcanic eruptions. The sulphate clouds reduce the intensity of sunlight, and this has a larger impact in summer when there is more sunshine. There is little strength in the Sun in winter (especially at higher latitudes) and reducing this further does not make much difference. Europe (as an example) gets most of its winter warmth from the sea, not the Sun. The term ‘volcanic winter’ is misleading: it should be volcanic summer – meaning that there isn’t one. A volcanic winter means that the British ‘summer’ rules the world.
The plot above shows the MXD record of Esper et al. The temperatures themselves are obtained from the MXD data by measuring the correlation between MXD and temperature for a 20th century data set. The number shown in the plot is obtained by adding up all 20 records.
The year 1453 comes out as exceptionally cold: the average over each site is -2.5C. (The total of -50C looks a bit strange but comes from 20 (number of sites) times -2.5C (per site).) The temperature remains a bit low for more than a decade. In contrast, the year 1459 is not as exceptional. Based on this, one would have guessed that the major eruption was in 1453 (or 1452), not 1458.
This study shows the impacts across the northern hemisphere. We also have the coral record from the (Indonesian) tropics which shows an increase in 13C uptake, possibly because of cooler water. How about the southern hemisphere? Here, the climate record is much less well known. There are fewer trees available for detailed study, and the effects of eruptions is expected to be less because there is so much more sea in the south. Oceans have a tempering effect which keep the temperatures more constant. Land responds much quicker to changes in solar radiation. Even Tambora’s year without summer, which was a tropical eruption affecting both sides of the globe, is much less clear in the tree records of the southern hemisphere.
There is a recent study of tree rings in South America, by Morales in 2020 (https://www.pnas.org/doi/10.1073/pnas.2002411117). They were looking for evidence of past droughts, based on the expectation that drought will be the main cause of poor tree growth in this region. This expectation is based on the rainfall variability that comes from the El Nino/La Nina cycles. The study extends from the tropics to Patagonia.
The results are shown above, where the vertical axis shows the percentage of the studied area that has wet or dry conditions in a certain year. They do not directly consider temperature, but it is of course possible that some ‘dry’ periods were in fact ‘cold’. Red shows times and regions which are extremely dry. The red lines correlate well with some eruptions. Below is the same plot, but now with some eruptions indicated by the grey lines: 1452, 1458, 1640 (Parker?), 1815 (Tambora) and the unknown eruption of 1695 which we have discussed here in the past.
This plot is the best evidence for southern hemisphere climate effects from eruptions. In contrast to South America, the (sparse) New Zealand tree record does not show this effect. It is plausible that indeed the main effect on South America is from suppressed rainfall coming from the Pacific.
It is interesting that both the 1453 and 1458 eruptions appear to show up. Both volcanoes affected the southern hemisphere. The published data does not show where the drought regions were in those years, so we can’t tell whether the effects extended across South America or perhaps were mainly close to the tropics. The result is suggestive but not conclusive.
To get a reality check on how well ‘tree weather’ compared to real weather, I went through a compilation of weather records from Western Europe. The descriptions indicate cool summers in 1451 and 1452, before the eruption. In 1453 the spring is already cool and the trees blossom very late. June is very cold and August very wet, with a very late and poor wine harvest. In 1454 this scenario repeats, with a claim that Belgium had 7 weeks of rain every day in spring and summer. In 1455 there is frost in June, and the wheat harvest is poor: there is famine. Only in 1457 and 1458 do good harvests return. But extreme weather hits in 1460 with an exceptionally cold winter. The Baltic freezes over, and people travel across the ice from Poland to Sweden. The following summer, though, is normal.
This confirms the poor summers during the early and mid 1450’s, with a proviso that the two summers before the eruption were also not great. The grape (wine) harvest in northern France is late (late September) from 1453 to 1456. Although such a late harvest does happen more often (it also happened in 1451), a series of four such years in a row is very unusual. The harvest was late again in 1459, but now only for one year.
All this should be interpreted cautiously. Weather is not a perfect proxy for climate. In most years one can find examples of unusual weather. It gives context to the tree record but does not replace them.
Many will be familiar with the reports of strange weather in Constantinople in 1453 (just before the city fell) with descriptions of a poor harvest from the city gardens, a 3-hour darkness from a lunar eclipse and fog. They have been highlighted in many articles on the 1453 climate excursion. However, these reports are doubtful. The description of fog comes from a document written much later. Its claim that fog is unusual here is not correct: winter and spring fog is not unusual in Istanbul, caused by cold air from Russia coming in over the Black Sea. The lunar eclipse did not occur on the claimed day but a few days later and was only partial: the description is exaggerated. These reports cannot be used as evidence because of the lack of confirmation. There are also no similar reports from any other area in the region: if this had been a widespread volcanic effect, it would have been described in other places as well.
Back to the ice
We are left with a major problem. The ice cores show a minor, probably northern eruption in 1452 or 1453 and a large southern-tropical one (was it Kuwae?) in 1458. The climate shows evidence of a major eruption in 1453, with evidence from tree rings, coral and human history, while there is at most a minor effect after 1458. What have we overlooked?
The Greenland dates for the ice cores would appear to be well established. The Vatnajokull eruption in 1477 gives a clear marker in the ice seen both in sulphate and in tephra, and is not long after the two eruption signals of 1458 and in 1453. There is a proviso here. We cannot be fully certain that this eruption was indeed in 1477. There is not a single description of it in Icelandic reports, in spite of this being the second largest eruption in Iceland of the past 1000 years. Carbon dating gives a 1480+-11 date. The association with 1477 comes from a report of ashfall in northern Iceland from March 1477. The association of the sulphate spike with Vatnajokull is supported by the cryptotephra, but the evidence for the year is more circumstantial. It is likely, but not certain.
The plot from Abbott et al. 2021 (https://cp.copernicus.org/articles/17/565/2021/) illustrates the situation well. It shows the sulphate concentrations at three stations in Greenland, whilst the red line shows one Antarctic curve, WDC. The 1453 and 1458 peaks are seen in both hemispheres; all other peaks are absent from Antarctica. The 1458 event has a stronger signal in Antarctica and the 1452 is stronger in the north. This suggests eruptions in the corresponding hemispheres, likely in the southern (1458) and northern (1452) tropics as the sulphate did manage to spread across the equator. The cryptotephra in the South Pole core suggests a far southern eruption in 1458, possibly in Southern Chile, but this seems inconsistent with the Greenland signal. An eruption closer to the tropics would fit better.
Suspicions have been raised about the dating of some of the Antarctic ice cores. The date of 1458 comes from counting of annual layers in ice cores from the Law Dome in Antarctica. (The Law Dome is a small, isolated ice cap near the Antarctic coast opposite Australia.) Similar counting from the Siple Station ice core from West Antarctica ice core puts the date of the large spike at 1455; several other ice cores also give an earlier year (Gao et al 2007 https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2005JD006710). Is it possible one of these is missing or is double counting some layers? Both teams appear convinced that their result is correct. The timelines have been checked with known other eruptions. The closest major southern eruption is Huaynaputina, dated to 1600. Both locations find this eruption at approximately the right time. The eruption in 1257 is also used as a check. There are discrepancies of 1-2 years but that is not unexpected. In conclusion, the Law Dome and WAIS cores gives an undisputed age of 1458 whilst the Siple core and the South Pole core give an equally certain date of 1453.
There is no clear solution to these discrepancies. The climate records show that the largest cooling was in 1453. There is some evidence for cooling in 1459 as well but not nearly as strong. The Law Dome dating indicates that the 1458 eruption was by far the largest, which implies that a smaller eruption in 1453 had a disproportionate impact on the climate. If the Siple and South Pole core dates are correct, then the 1453 eruption was much larger and came from the southern tropics, whilst the 1458 eruption seen only in Greenland must have come from a northern eruption at higher latitudes, for instance Alaska or the Aleutian arc. Another peak in the Antarctic ice cores is then dated to 1448 – a third eruption which came before the others.
Could the Law Dome have been miscounted? If so, this also happened in the separate WAIS core. Perhaps it is not impossible: there is an almost 150 year hiatus in the Antarctica cores, where no significant eruption was seen in the ice between 1460 and 1595. Perhaps something was missed, a few years of less snow making two years appear as one.
Or perhaps, the climate did not behave as expected and responded much stronger to a smaller eruption than to the large eruption 6 years later.
How large was this eruption, really? Was it indeed the second largest eruption in the millennium? It turns out, that is not easy to answer. The amount of sulphate that ends up in an ice core also depends on the vagaries of the local weather. Different ice cores can give different results, just because the wind took the aerosols to one place but not another. The plot below (made from data in Sigl et al. 2015) compares one Antarctic ice core (WDC) to three Greenland ones. The Antarctic core looks much cleaner: that is in part due to Iceland which erupts frequently and causes a lot of volcanic pollution in Greenland even from minor eruptions. NGRIP is particularly affected by Iceland. Laki, of course, completely dominates the Greenland record. The arrows indicate the three major eruptions, Tambora, Kuwae(?) and Samalas.
In the Greenland ice cores, the main eruption in the 1450’s was smaller than Samalas or Tambora. In the WDC Antarctic ice core, it was larger; this is also the case for the South Pole ice core. Combining Greenland and Antarctica makes it the second largest, ahead of Tambora. It is up in the air: different ice cores give different ratios, probably due to details of wind and precipitation.
The comparison indicates that most of the sulphate from the major eruption in the south. On the other hand, the fact that the climate took four years to recover indicates that there was a major injection into the stratosphere, which did reach the north over time and which took a long time to settle.
On balance, it seems more likely that the major eruption was in 1453 rather than 1458.
But was it Kuwae? The tephra in the Antarctic ice suggests it wasn’t: it indicates a more rhyolitic eruption which does not fit Kuwae. But they may have found grains from a separate eruption. The strong sulphate signal in Antarctica suggests a location in the southern tropics. Kuwae fits the location and the crater size, and it did have a large eruption at approximately this time.
What other options are there? South America is attractive, but there is no obvious 10-km wide, very young caldera – and this was only a few years before the Spanish extensively explored South America. How about New Guinea or the island volcanoes north of there? Or perhaps Indonesia, an island chain with a track record of VEI-7 eruptions?
The second eruption is either in the northern tropics or at higher latitudes, depending which year it was in. There is no obvious candidate in Central America, and Japan is too well documented to miss a large event at this time. Can we exclude Africa? There are more options further north. The jury is out.
The mystery remains. This may well have been the second largest eruption of the millennium – and we can’t even agree on when it happened!
To quote again from the Solitaire Mystery: “When you realize there is something you don’t understand, then you’re generally on the right path to understanding all kinds of things.” And it is important to understand what happened almost 600 years ago. For the past 200 years, we have not had a volcano with major worldwide climate effects. Krakatoa and Pinatubo reduced the global temperatures only a little. Have we become complacent? All the largest eruptions of the past two centuries were unexpected. Only one person saw Krakatoa as a danger before its climatic explosion: Verbeek. Pinatubo only gave a few months warning – just enough for evacuations, Hunga Tonga came out of the blue. Tambora was not even recognized as volcanic. And we cannot find the sources of some of the largest eruptions of the past 2000 years.
The Aztec used a cyclical calendar where eventually the same year would come again. And so it is with volcanoes. Eruptions have not ceased. The next major eruption will happen – even though it may come from a very unexpected volcano. 1 Rabbit will return. Are you ready?
Albert, May 2023
References (not a complete list!)
- The Aztec “Flowery War”: A Geopolitical Explanation
Barry L. Isaac, Journal of Anthropological Research 1983 39, 415-432
- The Famine of One Rabbit: Ecological Causes and Social Consequences of a Pre-Columbian Calamity
Ross Hassig, Journal of Anthropological Research 1981 37, 172-182
- Two likely stratospheric volcanic eruptions in the 1450s C.E. found in a bipolar, subannually dated 800 year ice core record
Jihing Cole-Dai et el., JGR Atmospheres 2013, 118, 7459-7466
- The 1452 or 1453 A.D.Kuwae eruption signal derived from multiple ice core records: Greatest volcanic sulfate event of the past 700 years
Gao et al. Journal of Geophysical Research: Atmospheres 2006, 111, 12107
- An independently dated 2000-yr volcanic record from Law Dome, East Antarctica, including a new perspective on the dating of the 1450s CE eruption of Kuwae, Vanuatu
C. Plummer et al. Clim. Past, 2012, 8, 1929–1940
- Timing and climate forcing of volcanic eruptions for the past 2,500 years
M. Sigl et al. Nature 2015, 543, 562
- Six hundred years of South American tree rings reveal an increase in severe hydroclimatic events since mid-20th century
M. Morales et al. PNAS 2020, 117, 16816-16823
- Coupling of Indo-Pacific climate variability over the last millennium
N. Abram et al. Nature 2020, 579, 385
- Northern Hemisphere temperature anomalies during the 1450s period of ambiguous volcanic forcing
J. Esper et al, Bulletin of Volcanology 2017, 79, 41
- 2600-years of stratospheric volcanism through sulfate isotopes
E. Gautier et al, Nature Communication 2019, 10, 466
- Cryptotephra from the Icelandic Veiðivötn 1477 CE eruption in a Greenland ice core: confirming the dating of volcanic events in the 1450s CE and assessing the eruption’s climatic impact
Abbott et al., Climate of the Past, 2021, 17, 565–585
- Annually resolved Southern Hemisphere volcanic history from two Antarctic ice cores
J. Cole-Dai, Journal of Geophysical Research: Atmospheres1997, 102, 16761-16777
- South Pole ice core record of explosive volcanic eruptions in the first and second millennia A.D. and evidence of a large eruption in the tropics around 535 A.D.
D. Ferris et al. Journal of Geophysical Research: Atmospheres, 2011, 116, 17308
112 thoughts on “The mystery eruption of 1 Rabbit”
This became a monster post – apologies! I hope you made it this far in the reading.
It is excellently written and about one of my favorite topics: mystery eruptions.
Other locations that might be culprits because they don’t have much written history going back to that era: the Philippines, sea mounts (there are loads), maybe Ecuador/Columbia, South Pacific.
Albert it was a spectacular read, you guys are on fire right now.
thank you for the fascinating read!
Read like a good mystery novel. Loved the cartoons. It seems most certain that we will discover more about these events. BTW, where does most of the funding come from for this kind of research? Government grants? Oil companies? Student tuition fees? Rich people? Thanks for your excellent work.
The research is almost entirely government funded. Oil companies don’t do this work anymore (it is of historical interest that the evidence for higher sea level in the past when temperatures were comparable to now started with research done by Shell). Tuition fees cannot be used to support research – at least in the UK where all universities have to provide detailed breakdown to the government of what the staff are spending their time on, in terms of teaching, research and admin. Similarly, the research money cannot be used to support teaching.
I think at least a few if these nystery eruptions happened in the equatorial Pacific, and were shallow submarine volcanoes or islands that blew up, very much the situation at Kuwae but giving more options. And, well, we literally got a demonstration last year… GeologyHub on youtube has hypithesized one of the calderas near Tongatapu might have been the 1809 volcano.
Really, if you go over the Tonga/Kermadec arc, abd also west through the New Hebrides, New Britain and Vanuatu, I dont think there is anywhere else on the planet right now that has more calderas in a narrow area. There are so many that very few of the volcanoes even get close to the surface, let alone form islands. Surely at least a few are young enough to be culprits, maybe even most of them.
“The composition of these grains did not agree particularly well with Kuwae. The particles were rhyolitic with 75% SiO2 while Kuwae grains were typically in the 60-70% range.”
This says to me continental, or back-arc volcanic system, especially at 75%. And if 1458 is more likely to be south of the equator, then I’d have to plump for a South American volcano.
Geologyhub covers some great things, little did I know there are volcanics off the coast of Spain (Valencia trough) that are <1million years old.
Yes, that is possible. Also a fairly inactive volcano where the magma had been stewing and cooling for a while. But the grains may not have been from the same eruption
Mt. Lassen continues to show signs of uplift…which appears to have accelerated since the twin shocks under Lake Almanor 36hrs ago.
Interesting. I had thought those quakes might have been related to snow melt destabilizing the lake bed, and was a bit worried about the dam.
Not according to USGS: https://www.usgs.gov/observatories/calvo/news/recent-large-earthquakes-near-lassen-are-just-another-day-basin-and-range
Cyclone Mocha have grown into a monster now in indian ocean
Very nice article Albert looks like there is many large unkown eruptions possible shallow submarine as well that left climate disasters for historical eras
Interesting article. Nice to learn some things about the Aztecs and the troubles they faced due to the volcanic eruptions of the 1450s too.
I have a candidate, though it is an unconventional one. I have an excel of lava flows from Hawaii with their volumes and age. In the excel the Aila’au summit overflows of Kilauea are written down as ~1455 AD in age, which is the average of several calibrated radiocarbon ages, and have a volume of 3.6 km3, according to my calculations. The Kalahiki episode, a series of eruptions in the SWRZ of Mauna Loa but where the vast majority of the volume was emitted in the last eruption, that are likely its most voluminous in the past ~2000 years or more, is written down as ~1460 AD in age, which comes from a single calibrated radiocarbon age, and has a volume of 4.5 km3. Aila’au was a slow eruption, but the Kalahiki episode was relatively intense. The final eruption may have lasted a few months to a few years, and both may have been ongoing at the same time at some point. While may not be the main culprit, it may be related, or have contributed to what happened in those years.
Here is my map of those flows, all are pretty narrow in area but seem to have been very thick flow fields. Kalahiki is a cone which probably had fountaining as much as 100 meters, maybe more. But the other two vents have no fountaining, the lava just welled out of the ground silently and fast. Seems it was a lot like the 1935 eruption, beginning on the rift but then going to an effusive flank vent. Or like Kupaianaha. I think it even left the rift zone at the end as one half of the Kipahoehoe flow field seems to just stop underneath the 1919 flow which is very narrow, SWRZ eruptions exiting the rift is not common from what I can see.
So seems like the eruption broke out at the upper vent, and stayed there for at least a while, enough to reach the ocean and build a large cone with a shield around it, probably with a vigorously active lava lake in the crater. Might well look a lot like the common eruptions on Reunion but much bigger.
I guess eventually the magma supply was either too high or the lake was itself too high or had degassed the magma under it, and then new dikes went downrift, like happened at Pu’u O’o in 1986 only because of the slope and elevation the magma was able to go much further.
I mapped at least two parallel intrusions.
Nice maps. I have studied this episode better than earlier activity episodes, because it is easier. I think the Kipahoehoe and Kolo erupted degassed magma from a shallow dike that was degassed upslope. This is particularly clear for Kolo, which doesn’t have any pyroclastic material around its main vent. But I think it is very likely that the Kipahoehoe vent was degassed too, given that it was entirely buried under thin 1950 flows. The Kalahiki flow has two different fissure systems formed in two distinct eruptions, both normal gassy fissures, Kolo seems to line up with the older Kalahiki fissure, and Kipahoehoe lines up with the more recent Kipahoehoe fissure. I think, speculation, that a dike formed from the upper SWRZ of Mauna Loa which produced the Kalahiki I flow, a shallow dike grew from Kalahiki I during the eruption and made the Kolo flow dowrift from a secondary vent (0.23 km3). Another dike followed and erupted from nearly the same place as Kalahiki I, making the Kalahiki II cone. A shallow dike grew from Kalahiki II and formed the Kipahoehoe flow downrift (0.6 km3 subaerial, 3.1 km3 in the submarine lava delta). Another shallow dike also grew and reached nearly as far downrift as Hapaimamu, making small ooze-outs of lava. The Kalahiki flow totalled 0.46 km3 subaerial, and 0.16 km3 underwater, after the two eruptions. There was at least one small fissure eruption shortly before the Kalahiki I flow. All the primary dikes seem to have radiated from the same spot near the Upper SWRZ of Mauna Loa, which is at present the down-rift end of the seismically active SWRZ. It is possible that the present configuration of the deep rift is related to the Kalahiki episode of eruptions.
Do you have maps of the vents? 🙂
Mine is entirely visual, not with any real research into dates. Only Kipahoehoe falls within the existing released new maps, and I otherwise just went on lava colour, fissures lining up, and in part your analysis.
I did try making a map that connects the southern flow field to the area of the vents. Actually one of the Kipahoehoe vents is exposed in a kipuka, small spatter cones but nothing larger. But there is really no reasonable way to get the lower flowfield to link, I think the 1919 flow buried a lower off-rift vent, one which was probably completely effusive with no spattering at all, almost like a tube fed breakout.
I can imagine Kalahiki being kind of like the center of Mauna Loa for this episode, kind of like Pu’u O’o was for Kilauea for a while, with a robust continuous connection. Maybe it intruded downrift multiple times but without killing the open vent somehow. I can imagine there being a lava lake there for a few years. Kilauea also would very likely have had at least two lava lakes at the time too, would have been fascinating if it happened today although perhaps at the time was less appreciated…
This is all very fascinating, but what I’m not seeing here is something that could have put gigatons of sulfate into the stratosphere and, thence, to both Greenland and Mexico. This eruption would have made bits of Hawaii hot and all of Hawaii stinky and that’s probably about it. The footprint ash eruption might have been able to loft sulfate high enough but occurred centuries too late. Is there any evidence for an ashy eruption in Hawaii in the 1450s? Otherwise my bet is still going to be on the Pacific islands/seamount chains and Indonesia for the eruption site(s).
Yes. I have checked the maps I have:
This was may former interpretation of the Kalahiki episode:
But the following interpretation is maybe better, with a single primary dike (orange), that created the Kalahiki vent. Then a series of secondary dikes, pink, yellow, red, intruding from Kalahiki more to the east each time, making fractures, and small oozes of lava that did not travel far, except for the major Kolo (yellow) and Kipahoehoe (red ) flows. The polygons are horizontal sections of the flow, measured from elevation contours, that I used to estimate the volume, at intervals of 300 feet underwater and intervals of 200 feet when subaerial. What is curious though is that the Kalahiki eruption shifted not only to secondary vents downrift but also its primary seat of eruption seem to have probably shifted at least once.
Keapohina was a lot like this, too. It erupted 3-4 times from the same location, and sent a few secondary dikes downrift, cracking up the ground heavily. And before that, Pu’u’o’keokeo, and the complex at 2900-3100 meters altitude, were possibly similar.
As for the sulphate, the time match was interesting so I commented based on that, but the sulphate injection is more likely to have come from plinian eruptions, I agree on that. Still, it is not impossible these Hawaiian eruptions may have contributed some sulphur dioxide to one of the multiple peaks visible during this time.
I forgot to include one fissure, which continues the red system down rift, reaching to the Manuka lava flow of ~1800.
Very interesting how at least the last few eruptive sequences at Mauna Loa were not really affecting the whole volcano and made huge flow fields like this. Probably has something to do with the caldera collapse that made Mokuaweoweo, Mauna Loa probably just doesnt have the summit storage required to erupt this way without collapse. I would imagine the Kipahoehoe flows probably erupted in the 10-100 m3/s range, so higher than Pu’u O’o but more lime that than it was like Holuhraun or 2018, and nothing like the rates of historical eruptions in the area. But at 50 m3/s it would have lasted 800 days or over 2 years
At the same time, probably a much larger area of the volcano has been resurfaced in the past 200 years than is typical for that time interval.
These eruptions are a type of their own, I think. They are wandering eruptions, where rather than having stable eruption vents, new fissures keep opening up.
The Keapohina Complex at 2800-2900 meters elevation is a better example. It has four vent complexes, each of which was erupting for a long time. They produced long-lasting lava channel systems and some lava tubes. Some of this complex have offset craters, as if there had been two different fissures running parallel 50 meters apart. There are also four shield-like structures of pahoehoe lava that erupted degassed magma, which were probably fed from shallow secondary dikes that extended down rift, from the Keapohina Complex. Late in the episode, a long fissure opened up through the west side of the complex and erupted voluminous fields of pahoehoe lava and lava tubes at low effusion rates.
Some of the 2000-year-old or more fissure systems, are even more complicated, although are more poorly preserved. Although to be fair, the vast majority of pre-Hapaimamu, pre-1660, eruptions in the SWRZ were similarly complex long -lived eruptions. Doing many short-lived, intense eruptions is something that started only in 1800-1810 with the Manuka eruptions, or maybe in 1660 with Hapaimamu, if it counts. In reality, doing many intense eruptions is more characteristic of a vigorous volcano with a mature plumbing. So those old long-lived vent complexes, although impressive, might be more characteristic of a volcano with a stunted plumbing. They are a bit reminiscent of Canary Islands’ volcanoes style of eruption, or even the penultimate, Morado Sur, eruption of Payún Matrú. While at present, Mauna Loa is actually more mature I’d say.
Is interesting to think about Kilauea then, it isnt doing big fast eruptions from its summit, perhaps it is presently less mature than Mauna Loa. I do keep coming back to all of the a’a flows that are exposed in kipukas within the Observatory flows on the SWRZ. To me it looks like Kilauea at one point was doing the same sort of powerful fissure eruptions as Mauna Loa now, and presumably not all that long ago, probably within the last 1500 years unless I am missing something. Maybe it is approaching a similar point now, the current seismic axtivity at the summit is much more extensive than the other post-2018 eruptions, it might be showing the whole chamber not just Halemaumau.
Did Hawaii did any plinian eruptions during the 15th century? We know that also Mauna Loa had explosive eruptions.
There was an explosive eruption around 1510 in Kilauea volcano. Uncertainty in the dating is large enough that it could well be a few decades earlier. But the volume is not substantial enough, VEI 3-4 event.
Excellent article !!
FWIW, are there any records of a major tropical eruption encountering a cyclone or hurricane ?? Beyond local lahars, much of the expected ash would vanish down-wind, probably fall off-shore…
Pinatubo! It occured during a typhoon
Excellent post, Albert!
I’ve always wondered why Pinatubo’s 1450-1500 eruption (the last before 1991) never comes up as a possible source for the NH weather in 1452/3. From what I’ve read, it was on par w/ 1991.
Worth considering! The 1991 eruption was too small for a major weather impact. But the earlier ones may have been larger
Correct me if I’m wrong, but didn’t Pinatubo’s climactic effects create some pretty wild northern hemisphere weather from autumn ’91 through winter ’93? Growing up in the northeastern US, I remember some truly epic snows and spring storms from around that time.
One of the reasons I think Pinatubo is worth another look is I always read the 1452/3 eruption was smaller than 1458–small enough to be a 10-15km3 eruption. But as you said in the article, it’s kinda hard to tell from the ice core signals.
Finding potential sources for mystery eruptions is a pastime of mine. Thanks for your reply!
I remember ice on the sidewalks and sea level snow (didn’t stick) in San Francisco in winter of I think 1991. Both are unusual for that climate.
California has been very unusually cold and wet this year. The jacarandas down the street still don’t have all their leaves and normally they are littering the neighborhood with purple flowers in mid-May.
1991 we have to look on the combined effect of Pinatubo (VEI6) and Mount Hudson (VEI5). It was one of few years with multiple large explosive eruptions.
Are there reports about tsunamis following the eruption of Kuwae? If the eruption was indeed a VEI7, the tsunami must have been at least as high like Krakatau’s 1883 tsunami.
Great post Albert, had to read it twice and slowly !
Great detailed post. Pity no conclusion but applauded the detail and amount of time it must of taken to produce.
Here is a nice video of a small pyroclastic flow on Semeru, from yesterday I think.
Dome collapse? Didn’t look like there was much activity at the summit beyond a moderate dust cloud kicked up by something. I doubt there was fresh magma involved here at all. At most a phreatic explosion or two.
Semeru is apparently basaltic andesite mostly (Smithsonian = source)
I noticed the plume didn’t go up very high before things went downhill, so to speak.
Tallest mountain on Java, though.
It isnt very fluid but definitely a different sort of magma to the sticky stuff erupted at Merapi or Sinabung. The basaltic andesite at these volcanoes is more like dacite or rhyolite that has alot of mafic crystals, so is overall in the basaltic andesite range. Semeru might be more like andesite magma with possibly less percentage of mafic crystals, but enough to stop it being free flowing. Its eruptions dont form domes really, all the info on it says it does but videos of it show otherwise, it just oozes sticky but mobile lava that flows down its steep slope and piles up until it becomes unstable. The end result is the same but the mode of eruption is very different, it isnt peleean like Merapi or Shevluch, probably closer to strombolian than anything else, but less explosive.
Semeru doesn’t seem terribly explosive though, based on a quick look at its eruptive history in the last several hundred years. Lots of VEI 2. I guess that is ideal for building a gigantic stratovolcano.
Great ALBERT !
It shows how difficult is, even with very sophisticated techniques, find sound truth about the past.
Sometimes we had to stop and wait until something NEW can give independent data (a new method, completely new samples). That’s HOW SCIENCE WORKS !
Fantastic detective work! It is difficult to construct the past before the global science (beginning with Global Britain?) could make professional records of events. History and geological history are much more difficult than law oriented sciene.
Climate and weather are complex dynamic systems. Small changes can have big effects. The swarm of conditions is difficult to survey. The Little Ice Age was from 1400 to 1800. Astronomic, volcanic and human made effects may have added to each other. In it the period around 1450 may have had a spike downwards. A short term climate change around 1450 can easily have caused a major desastrous change in weather in Mexico. Weather is more variable than climate. We’ve noticed the changing years of draught and floods in several parts of the world since climate change has begun. It is possible that around 1454-55 there was a perfect event for cold weather in Mexico with advection of Canadian cold air and a regional weather pattern which conserved the cold air.
Too bad there was no recent Miyake-event before 1450’s.
See e.g., Michael Price, “Marking time – Radiocarbon timestamps left in ancient tree rings by cosmic ray bombardments can date historical events with unprecedented precision”, published in Science, 13 Apr 2023.
Yes, there are no such markers in this period. There are two good markers before 1000AD from cosmic-ray spikes but none in the middle ages. Volcanic eruptions are used instead but that can lead to a circular argument when dating the eruptions. The 1477 eruption is a case in point since it was originally dated from ice cores, I believe. Then one document was found with an tephra fall for that year, and now that eruption is used to date the ice core. It may be right but is a risky way to certify dates. Another independent date would be most welcome
What causes such spikes? Nearby supernovae?
Not known. Nearby supernova are too rare. Major solar flares are one option, another one is an extreme gamma ray burst
Oh, great. So somewhere out there is some thing that will, every few centuries, blast our planet with radiation at levels greatly exceeding the Carrington event, and we’ve no way of seeing it coming? So, one day, zzzap, every astronaut and everyone in a plane, fried, half our electronics, fried, our power grids, fried, half the population of Tibet and the Altiplano, fried, and most of everyone who doesn’t get fried on the spot will starve during the following month or so. Long, hard, laborious rebuilding of civilization for whoever still lives, for generations. Basically, all the worst consequences of World War III, but without the fun bits. Lovely.
It would explain the Fermi paradox though, if nobody can quite get to self-sustaining space colonies in between two of these events. Every civilization that gets electric power, and then becomes dependent upon it, knocked back down when this comes around again, like trying to build it all out of beach sand but every twelve hours the tide comes back in.
I think they should also try taking ice core samples from the Andes/Himalayas/Alps/Carpathians etc. to narrow an area down. Well maybe not the Andes… It is slightly tougher to find long-glaciated mountain ranges south of the equator that aren’t volcanic themselves.
These exist but are hard to analyze for older data. Too much effect from melting. Here is one of the better ones from the Hamalayas
Makes sense its the highlands beacuse lowlands at latitude 19 ( Yuccathan Penninsula) are searingly hot all year around, Chicxlulub area often see 33 c in winter and up to 40 in summer combine that with the high humidity of a warm ocean and you set up conditions that are as bad as Singapore If not worse in summer
How cold was these highlands during the last glacial maximum? Any glaciers? Highlands experience dramatic cooling and drying during a low cO2 Ice Age. I do think global cooling is just as bad as global warming, beacuse rainfall is very much reduced during cold spells. During LGM most of Earth was very dry and desertic and woud be useless for agicultural stuff. During a Severe nuclear winter there Maybe a 90% drop in rainfall same with a volcanic winter
Infact most of the civilization disasters have happened during cold dry spells where agicultural activities have been slowed down
With my own VC article I wants it in a document so I can write on it on phone before its posted next week, as its not done yet after Albert done the first edit.
Woud be good to have an edit of my own article as soon as possible so I can write on it on phone
I dont have acess to computer now
But have it shared as
a google document woud be good
I think one solution that to certain unknown eruptions is that these eruptions weren’t massive but were actually extremely rich in SO2. Laacher see wasn’t that much larger than Pinatubo 1991 but produced an SO2 load matching or exceeding that of Tambora, a VEI 7. It would stand to reason a minimal VEI 6 be the cause for at least of one the mystery winters in history.
Alkaline magmas like Phonolites are very much more volatile rich than subalkaline magmas
There have been possibly 3 quakes this afternoon at Hekla, two of which were deep.
These quakes happened about 3 hours ago and no signs of eruption yet, but the likelihood for a sudden Hekla eruption is a little bit bigger this evening. If a more moderate M3 quake occurs, then an eruption could be likely. Otherwise it still indicates magmatic movements that could result in an Hekla eruption sometime in the next few days or weeks. Hard to know.
Interesting times in Iceland for sure. Not been on here for a while as a lot of family problems. So I am hoping to be able to keep a bit informed againnow grandchild needs less care. I knew many years ago that Hekla was well overdue and quite a lot of years have passed since then so it must be very poosible things could start soon especially with seismicity seeming to increase throught Iceland. so thanks for the heads up.
Although it’s only 3 they seem to form a similar trajectory to the fissure itself. Like you say, it’s very temperamental and it seems to erupt with little warning.
I think we need to see more, the system is a lot more sensitive than in 2000, and the whole no-quakes thing was probably because of erupting every decade which has since stopped. Earlier eruptions quakes werent noticed but anything under mag 3 probably wouldnt be noticed except at very close range where people were not going to be., it is a mountain in the Arctic after all as well as one with a reputation. Hekla isnt unique for erupting without felt quakes, the entire quake swarm up at Kilauea I have talked about for weeks now, has had maybe a few felt quakes, out of thousands. Many stratovolcanoes that are active will erupt without felt quakes too.
Not that I think we will need a big swarm, but definitely not just 3 quakes in a line on the mountain, tens of quakes at least.
How does the swarm before an eruption look like at Hekla compared with f.e. Grimsvötn?
Probaly similar as both are open conduited fast intense svarm and then boom and perhaps not that much Earthquakes
There is no comparison. Hekla is quiet until an hour before erupting. Grimsvotn shivers for years. Actually we do not know what to expect from Hekla at this time. The sudden eruptions were when the conduit was still fairly open from a previous event. It has now been decades and there is probably a nice solid plug in there. In the 19th century, there were reports of earthquakes as much as a day before Hekla erupted. Still no comparison with Grimsvotn. Most Icelandic volcanoes give you a decade of warning, at least in hindsight. Fagradalsfjal was discussed here on VC several years before the eruption because of earthquake swarms. Not Hekla. Well – we discuss it all the time because of its reputation, but have very little to go on. Even Carl, our most uninhibited volcaneer, said he would not want to climb Hekla!
Grimsvötn does run up quakes as the increasing magma chamber pressure puts strain on the walls
The eruptions there are a short intense svarm when the magma breach the caldera roof. I doubt it will erupt this year either. Grimsvötn can go decades without, but I doubt it will be a long silent period for it. 2011 was a much bigger than normal eruption and apparently takes time to recover the direct magma supply to the summit is likley fairly small
I understand the longterm differences. But what’s on the day of eruption?
Iceland’s catalogue tells about Grimsvötn that “The outbreak of eruptions is preceded by a 1-10 hour long swarm of earthquakes reaching magnitudes 3 – 4.”
Hekla: “For eruptions of Hekla volcano the only observed signals are earthquakes up to 90 minutes before eruption breaks out.”
The timeframe on the actual first day of eruption is different. What did Grimsvötn show on May 21st 2011 before the eruption began?
I don’t know the 2011 Grimsvotn sequence. For Hekla, there may be no felt earthquakes until 15-30 minutes before eruption. It seems to be a very fast affair with magma coming suddenly from some depth and arriving explosively. Grimsvotn is wet (the ‘votn’ part gives a clue) so probably less of a temperature gradient, a ductile conduit and a hydromagmatic explosion – and not much more. Hekla can produce copious lava while Grimsvotn produces little.
OK, thank-you Albert! Hekla is even more awesome, if you can’t feel the earthquakes as a mountain hiker. Iceland’s Volcano Cat adds that in some cases water supply for creeks around Hekla ceded before eruptions.
How dangerous is the solid plug in Hekla? Can it lead to a horizontal eruption like St. Helens (on smaller size)? The plug in St. Helens was made by Andesite magma of previous eruptions. There the magma type can change from eruption to eruption. Hekla does the variation of magma within a single eruption. So there can a viscous solid type of magma have been left behind.
Hekla erupts from a rift, and therefore the magma can change along the rift depending what was left behind in the past. St Helens is a bit different in structure.
The drying up of wells is a known precursor of eruptions, seen for instance at Mayon. It is caused by inflation, which reduces the water table by raising the ground. At Mayon it happens weeks or months before an eruption. We found indications for something similar in Krakatau was happening a long time (50 years) before its catastrophic 19th century eruption, perhaps one of the reasons the island was abandoned around that time. Verbeek never said what it was that made him concerned about Krakatau several years before it began to erupt. I expected it may have been signs of inflation.
Norway’s second volcano (not counting its overseas territories) has been discovered! Murky business
Popocatepetl has been very active lately. Sulphur dioxide emissions ramped up substantially in February, eventually peaking on May 7 at 5650 tonnes/day of SO2. Although it is not the first time that Popocatepetl goes over 5000 tonnes/day. Explosions are happening frequently, with as much as 6 different vulcanian explosions on May 15:
First signs of a developing El Nino detected in the Pacific
The nutrient rich cold water current at Pacific Equator there will be replaced by sparkling clear blue tropical waters 🙂
I do love the North Pacific Gyre having the most blue and nutrient starved waters on the planet
Here’s the latest US CFS forecast
And current Sea Surface Temperatures passed previous record (2016) back in March.
A question for our weather experts: is there any chance that the cold spring in western Europe, with frost in places in mid May, is still related to Hunga Tonga?
Here in Italy on the meteo websites climatoligists made seasonal summer forecast for a record high temperature 2023 Summer…we will see … (I hope they will be wrong, I can’t bear another summer with 45 days in a row with maximum temperatures exceeding the 35/38 °C like in the 2021 summer)…they say that “El Nino” effect will push up temperatures
If HT is involved, it’s a second or third order effect.
While ENSO just “technically” moved into El Nino territory, it’s based on ONI which is a 3 month running average.
In reality, it’s the atmospheric teleconnections that drive our weather and climate, and El Nino-ish teleconnections were starting to emerge as early as late 2022…primarily the emergence of a southern jetstream (a classic signature of El Nino), an eastward migration of the mean NPacific Walker circulation, and a significant/persistent negative shift in the AO (Arctic Oscillation) i.e. a southward shift in the sub-polar jet.
In response to the strengthening jet(s), high pressure over the NPacific/Bearing Sea was periodically displaced/amplified well into the Arctic which on several occasions, bridged with equally strong/large H.P. centered over Greenland and the far NAtlantic. That put western Europe under persistent troughing on the east flank of the Greenland High, not dissimilar to what’s occurred here in California along the eastern flank of the NPacific High where record snowfalls (nearly 1,000″ of snow fell over Mammoth Mountain in the southern Sierra!! and widespread totals of 600-700″ of snow down as low as 6,000′) plus several storms that dropped snowlevels to near sea level in the normally warmer N. Sacramento Valley. Overall, this year has been of the most persistently colder than normal Winters on record…though interestingly we never got a true Arctic blast that can drive temps down to the ‘teens (F)…just steady, bone chilling cold with frequent rain/snow.
But is HT causing these “localized” cold temps? With the planet as a whole now rapidly approaching records for the hottest it’s ever been, (note much of the East Coast of the U.S. did not see hardly any snow during one of the warmest Winters on record), and with the Pacific Ocean about to vomit a humongous amount of stored heat into the atmosphere (from El Nino), the building temps over next few years are going to wreak havoc over much of the planet (but that’s a subject for another post).
The bottom line, there is little/none data (that I know of) to suggest that HT has caused any kind of planetary/hemispheric “cooling” that is usually associated with large volcanic eruptions. So that leaves only the WV that was injected into virtually all levels of the stratosphere as a possible smoking gun of a HT effect. The physics suggests that WV in the stratosphere should have a net warming effect due to GHG warming…i.e. a strengthening of the inversion above the tropopause….which in turn would induce a generalized downward “pressure” on the troposphere thus intensifying domes of High Pressure, and inhibiting vertical heat transport flux and helping sequester heat near the surface instead of re-radiating out into space.
So, in a nutshell, it may be the HT has actually warmed the planet and altered the characteristics of High Pressure systems globally which due to their altered location and amplitude, are resulting in localized zones of periodically much cooler weather like western Europe and western NA that are around the flanks of the H.P. systems (forming Rex and Omega blocks), with equally anomalous heat elsewhere…especially areas that are directly under a dome of H.P. (like what just happened over NW Canada as persistently above average heat and dryness have triggered massive wildfires that ATTM is producing smoke across the entire NA continent (west-east) and well into the Atlantic.
In the past years northeast wind directions have happened more frequently in Europe. This moves cold Russian air to Europe. It reminds to trade winds, although it is not the same. But climate change changes weather much more. Westerly winds have decreased and meridional winds increased.
Can anyone tell me what this seismic signal is? Looks like Tornillos to me..
What volcano? 🙂
Not sure if this is magma tremor, not from an intrusion anyway although possibly it is movement within the chamber. Kilauea does these constantly and it looks exactly like the chart. But that is in a volcano with very fluid magma, I presume your volcano is more on the rhyolitic side so it might be more of a hydrothermal signal in that case. I am assuming these signals are from lower viscosityviscosity fluids.
I am getting tired of being teased by the volcano so I am giving it the silent treatment. So unless something significant happens, I’ll be very vague about my language. but since you asked, It’s at CCN. The IGEPN and SGC are taking this pretty seriously now as they’re adding new instruments almost every year and this one of them
I would take these as hydrothermal signals then, which doesnt mean magma isnt rising too but from the looks of it lava is not fluid in the slightest at CCN so probably wont make fluid movement tremors. But someone who knows more about seismology is probably going to correct me.
What’s off about these signals is that whenever the volcano starts producing more fracturing earthquakes, they weaken substantially but when the VT quakes slowdown, you see these signals get stronger and more frequent. I don’t know where exactly this station is but 2 other stations are practically right on top of the hydrothermal chambers but these signal are far weaker at those instrument.
Found this on YouTube. Some of the narrators’ explanations made me cringe, but the footage is spectacular, and certain descriptions are interesting:
I enjoyed it, but as an atmospheric scientist I was sorely disappointed they didn’t mention a) the massive coherent Lamb (pressure) wave that circled the globe multiple times (my personal weather station detected its passage at least 3 times — twice from the NE and once from the SW), and b) the meteotsunami that was detected even in the Atlantic ocean.
Yes, the pressure wave was quite an event. We saw it for 3.5 days, but this was close to the opposite point on the globe where the wave amplifies a bit. The first time, the amplitude was 2mbar – even at this distance! The bit about the tsunami seemed to mix the tsunami height of the wave and the run-up height.
Yes, I didn’t like either the way they explained the tsunami and pressure wave; they missed some of the most interesting questions. And also, the bit about the empty subterranean chamber suddenly collapsing was unrealistic. It would have collapsed gradually.
I also sometimes feel this extraordinary event (Lamb wave) is under-represented. Goes in hand with some quotes regarding the total energy expended by the event which I do not appreciate very much.
And indeed, I also have only ever seen the one photo mentioned here of the column on Jan 15. It is a bit a Pinatubo-like situation, where most material circulating is from before the large events…
Same for Krakatoa: the famous picture of its eruption is from a ‘minor’ blast a few weeks before. Pinatubo was hiding in a typhoon so has an excuse. For very large eruptions, if you are close enough to see a plume, before it gets completely dark from the ash, you are unlikely to leave a permanent record of it!
Indeed, there is an implicit effect of large eruptions making it impossible to get close-in photos. It was a grace of nature that HTHH is so remote in that sense. But still it would be fantastic to get more high res photos e.g. from the main island.
Albert, you have seen it already? Supernova 2023ixf in M101. Closest core collapse in more than a decade.
Maybe supernovae now indeed are giving a real effort in catching up to the volcanoes 😉
I hadn’t heard! Outer spiral arm, I see. Is there a known progenitor?
Progenitor, I think unknown. I hear there is an immediate precovery image found in retrospect by ZTF, around 16mag, but only upper limits from a few days earlier still.
Closest cc in more than a decade however is not exactly correct, sorry, that was my La Palma biased world-view. Cen A had one in 2016 of course.
Thanks so much for this, I’ve been struggling to find more ground level footage /images of the eruption column. Google is saturated by images of the satellite imagery and then pictures of the Jan 14th eruption which was observed up close.
Now of course most of the Youtube footage I’m familiar with is from the surrounding islands and quite far away, but I figured there had to be someone on the water that survived and has spectacular footage. I wish this documentary showed more of what they captured, but at least I know something is out there!
Let me clarify that I just mean unobstructed (by island, trees, etc) clear footage from a strong vantage point like exactly what they showed in the beginning of the doc, however brief. There’s one good image that has a write up on it marking the pyroclastic flow at the base of the column and is the clearest, best image of the eruption column I’ve come across. It was shared here way back, I believe by Hector as well? I can dig it up if anyone hasn’t seen it. But I’m looking for more along those lines.
And yes, I’m happy loss of life was minimized, and thrilled the people that captured the footage in the doc survived a precarious situation with the looming tsunami.
Yes, I’ve also been hoping for some good footage of the eruption column during the climax. I also found very impressive the images of a massive, steam-rich co-ignimbrite cloud, during the precursory activity of Jan 14th. After searching on YouTube I found a better version of the Jan 14 th eruption:
Very nice and high resolution.
The way I see it, activity escalated gradually towards the final ignimbrite event. With more and more powerful explosions. The crystal-poor, basaltic-andesite magma of Hunga Tonga is very fluid, and yet the explosions were quite remarkable in terms of size, which could have given some warning of what was to come.
If I’m understanding correctly the enormous column on Jan 15th was something like 1/3rd of the total erupted volume, yes? The remainder was ejected in a massive underwater ignimbrite?
I’ve read some papers that take the total volume as high as 20ish km^3, but with odd methodology so I’m sure a borderline high 5 to low 6 is most likely. Still, what an incredible event that I still find myself thinking about nearly daily.
There is a very well written follow-up by Albert here on this page. As always, uncertainties.
To me, in a way what characterises HTHH is not the total ejected volume (which, while sizeable, was surely smaller than several well known larger eruptions), but the intensity with which it happened. That was surely extraordinary, and may well be a once in a lifetime event. As such, I always like Albert’s original nickname “The Millenium VEI 5”. A large, but not astronomical, eruption, that was however vastly impressive, and displayed phenomena way beyond what was previously believed to be classical VEI 5 terrain…
My Volcanocafe Article will be posted tomorrow
No spoilers from Albert! 😉 more than it will be very fun
The ‘swarm’ at Hekla is still continuing.
Hekla is the only volcano where 1 or 2 quakes a day is considered a swarm.
Remind me, why is Hekla so quiet before erupting? Never understood it.
Because we have only got seismological data from when it was very active, and no one could feel any quakes earlier. There were reports in 1846 up to a day before the eruption of an audible low sound, from tremors, so Hekla is probably not silent if it goes dormant long enough. It has been 23 years since it last erupted which might be getting towards long enough for this to come into play.
It is important to remember how small the small 1 and 2 quakes are. All of the many thousands of earthquakes that have happened at Kilauea in the past few weeks that I have been commenting about, almost every single one of them was too small to feel, if you were there you wouldnt suspect a thing, until a mag 3+ happens just below surface in Halemaumau and lava blasts out within the hour, there were people present in December 2020 who had no idea until the crater glowed like the sun comign up and the steam cloud blew out. Hekla really is not all that different, if Kilauea had only one rather basic seismometer that could pick up mag 3s or above but not lower, then it woudl also appear to be dead silent until under an hour before it erupts. Hekla just goes years between eruptions, and the opening stage is usually very powerful, so when it goes it really goes big.
Hekla probably produces the same microseismivity around its magma chamber as Kilauea and every other inflating volcano, but if its magma chamber is 15-25 km deep instead of 3 km deep, then that wont be noticed by anything at the surface. It might well be impossible to accurately resolve this over the background.
Also, probably the obvious fact that even ignoring its reputation, Hekla is still a tall mountain in the Arctic, the weather is much more dangrous than the volcano, very few people are going to be in any position to feel any quakes coming from it especially historically when mountaineering was far more dangerous than it is now. Plus, just like a hypothetical unlucky idiot who climbed down into Kilauea and felt that big quake right underneath them, anyone who is close enough to Hekla to feel its warning is probably not going to get out of the way fast enough to tell anyone about it later… 🙂
Basically, Hekla is a relatively normal young stratovolcano, relatively open and with a hig hrate of supply, so it doesnt need to break open a pathway to the surface from the bottom of the crust. But such volcanoes are very weird in Iceland, where most volcanoes do big eruptions in rifts that let the whole country know they have opened, and weeks in advance, before flooding everything with lava. The weirdest thing about Hekla is that it isnt conical, but it is not absolutely unique in that regard either. Possibly it is becoming conical too, 1971 and 1991 had radial vents instead of a fissure.
While we think much about the explosive phase of Hekla, it is often pretty short:
“In the 2000 CE eruption of Hekla (VEI 2-3) the eruption plume rose rapidly to 11-12 km a.s.l., the most intense phase lasted about 80 minutes and tephra fall was mostly over in 3 hours.”
After three hours the tephra fall was over, and the effusive stage took over. The explosive phase is spectacular and makes great images, but most of the eruption is effusive with mainly hawaiian type and only a bit strombolian. The effusion of lava can begin at the same time as the explosive eruption phase or begin later. In small eruptions the effusive phase lasts days do weeks. Moderate eruptions make lava for weeks to months.
All good info. Too many Icelandic volcanoes are stuck in neutral, Katla and Grimsvotn have already had their time to tease so I guess it’s Hekla’s turn
Youtube has some nice old eruption videos, here f.e. 1970 which shows the lava fountains and ash clouds on first day: https://www.youtube.com/watch?v=N7WP20BxynY
Nyamulagira is active…!
And here is some daredevil volcano reporting from 1980, from the top of Mt. St. Helens 17 days before it exploded. Complete with geologist with pick and a helicopter. And several small rockslides.
Fantastic find, and really depressing to see how far typical news media have deteriorated in the last 40 years. Today, they would be standing in front of a greenscreen with animations of Yellowstone erupting in the final product, and the anchor would be asking things like:
“Is that an American volcano?”
“Is that really fire coming out of the Earth?”
“Aren’t there a lot of experts who say volcanos originate from burning coal deposits?”
“Is that dangerous to me?”
“How will the stock market react?”
I must have put a typo in my email address, got a different avatar.
In afternoon today we will post my VC post and will be the first of its kind on VC, its a subject that needs to be talked about
New post is up! Edgar Allen Jesper: The Pit and the Pahoehoe
Hahah I dont know If they are pahoehoes in traditional sense these are ”flood lavas”
Yes a New article is up as Albert says
Have a fun time reading! : )
The entire matter is less confusing than you have presented.
Major eruptions occurred both in 1452 and 1458, with the former taking place in the Northern Hemisphere (NH) and the latter in the Southern Hemisphere (SH). This is well-established in the chronologies of SP19 and WD2014, which have been synchronized across multiple Antarctica ice cores.
You correctly observed that tree ring records and historical accounts indicate a significant cooling event in 1453, but there is little to no evidence of cooling in 1459. Additionally, the 1458 sulfate peak in Antarctica is considerably larger than the sulfate peak in 1452.
However, it is important to note that all the tree ring records (from Europe, North America, and Northern Asia) and historical accounts (from Europe) are from the Northern Hemisphere. Naturally, the Northern Hemisphere responds more dramatically to eruptions that occur in its region.
Recently, the first tree ring density-based reconstruction of past summer temperatures for the Southern Hemisphere was published in VICS 2023 – PAGES (https://pastglobalchanges.org/news/137267).
The coldest decade in the Southern Hemisphere over the past 640 years was from 1454 to 1464 CE (so predominantly occurred after 1458). The single coldest year in the Southern Hemisphere was 1459 CE, in contrast to 1453 in the Northern Hemisphere.
It is clear that the eruption in 1458 was at least of similar magnitude to the eruption in 1452.
Thank you for this info. (The comment was held back by our spam demon: this happens to all first time commenters, sadly for good reason. Any further comments should appear without delay.)
Your link is meant to go to the following abstract, I believe:
Significant volcanic cooling expressed in a summer temperature reconstruction from Northern
Rob Wilson, Emily Reid, Rory Abernethy, Ricardo Villalba and Ignacio Mundo
No traditional tree-ring (TR) density-based reconstruction of past summer temperatures exists for the Southern Hemisphere. It is therefore no surprise that current published ring-width (RW) based temperature reconstructions provide ambiguous evidence for past volcanic forcing in the Southern Hemisphere. In this study we present a new January-March summer temperature reconstruction (1381-2016) for Northern Patagonia based on RW and Blue Intensity (BI) parameters measured from Araucaria Araucana trees from 6 locations across the middle to southern end of the species’ range. The multi-TR-Parameter reconstruction
explains 53% of the summer temperature variance (1902-2016) which is on par with similar TR based reconstructions from the Northern Hemisphere. The reconstruction coheres strongly with surface mean air temperatures for a large region in South America from 48-37S / 75-65W including sea surface temperatures well into the eastern Pacific for these latitudes. The warmest 11-year period is 2006-2016 while the coldest period is 1454-1464. The coldest reconstructed year is 1459. Superposed Epoch Analysis focussing on significant tropical eruptions since the 1400s indicates a significant mean cooling of ca. 0.5-0.6 degrees Celsius, depending on which volcanic events are used. The degree of relative cooling is on par with the cooling represented by individual TR records used in the Northern Hemisphere N-TREND reconstruction suggesting that the volcanic response in northern Patagonia over the last 6 centuries is equivalent, or even more extreme, to what is observed in many Northern Hemisphere locations.
Reading the abstract with more care, the result applies to Patagonia, i.e. the temperate zone. It must have been a major eruption but it had more limited impact in the north, so a large explosion fairly far south. The effect was only one year in the north, while the 1453 eruption had a four year impact. The ocean data indicates that the 1453 eruption had a more wide ranging effect, including the tropics around Indonesia, and reaching parts of Antarctica. The 1458 one perhaps mainly affected southern South America. Does Kuwae fit either one? It doesn’t seem we c an answer that question yet.
Yes, that’s the abstract I was referring to. If we were to assign Kuwae to either 1452 or 1458, it would have to be 1458 since the 1452 spike is only faintly recorded in Antarctica cores.
However, I have doubts about it. The published radiocarbon age of Kuwae pyroclastic flows (Monzier et al) and the lake age-depth model of distal Kuwae tephra (Strandberg et al) both indicate ages that are too young for 1457 CE. The radiocarbon age of bone collagens from Ti Tongoa Liseiriki also indicates that the majority of the age probability density is before 1457 CE.