Who doesn’t love a good mystery? The allure of the unknown captivates all, no matter one’s social, political, religious, or scientific standing. From dark matter to what could lie beyond death to the ending of the Simpsons, these almost incomprehensible ideas steal our thoughts.  I would contend that we Volcanic fanatics have some of the best mysteries in academia. So many sciences intersect at pinpoint mysterious larger eruptions. No single field can handle the unknown eruptions of our past. The eruption of Samalas was the biggest mystery eruption of the last few decades for good reason, as it was the largest sulfate eruption in the last 2500 years, with major famines across the world. But now the mystery has been solved, and UE 1809 is the one getting all of the attention. As you probably already know, I find this event to be rather boring. The eruption had the misfortune of being placed in between the Laki and Tambora eruptions, and both of those had bigger impacts on society in 1809. It’s really not my cup of tea, and there are other eruptions that I believe should have way more attention. In this article I’ll shed some light on some eruptions that have caught my interest.

All throughout history, years, decades, or even centuries have been singled out for terrible living conditions. The global war and a deadly pandemic in the 1910s, a massive volcanic winter and plague of the sixth century, and more. The 17th century was a horrible century for all; some of the biggest wars, the biggest famines, and the deadliest plagues impacted the entire globe, and no one was safe.  One of the decades in this grim century was special; the 1690s is singled out for massive famines over a large area in northern Europe. The years 1692-1698 were bad for the harvest; cold and wet summers in conjunction with terribly cold winters destroyed the harvests for many, and as such, Finland lost a third of its population, Estonia lost 20% of its population, and Scotland lost 5-15% of its population. Lesser but significant cooling took place in Western Europe and East Asia; 1695-1697 were especially bad in the coldest decade of the Little Ice Age. The famous George Mackenzie paints a grim picture in Scotland.

After subscribing to his tack, he immediately went north to appoint collectors in the several towns and shires and to regulate the brewers, but shortly after, there happened a great scarcity in the northern countries, and brewing was for the most part given up, so that it was not possible to make up the tack duty.

Your Petitioner, foreseeing the sad and calamitous condition and the apparent famine in these places, and finding that there was not the least possibility for him to make good his tack, made application first to the principal tacksmen and then to the Lords of the Treasury, who, after consideration of what he had represented, gave him a gift of execution as to one half of his tack duty.

Thereafter the sad and deplorable Condition of these Countries increasing, the Coun∣try Brewers were so far from continuing to Brew, that there was not Bear to be had to make Meal of to keep in their Lives, so notwithstanding of all the Trouble, Fatigue and Expense your Petitioner was brought to, it was not possible for him to make one half of his Tack-duty, and yet to save himself and his Cautioners so far as he was able, he has payed in what he has collected, and near one thousand pound sterling more of his own proper Stock, which goes very near to ruine him, but he yet lying under the Obligation of his Tack to pay 9000 lib, sterling, which he never received, he is necessitat humbly to Address the Honourable and High Court of Parliament in this matter.

For years, the main cause of this famine was thought to have been the Little Ice Age. The LIA peaked in the 17th century and caused other major famines within the 400 years it lasted. This assessment wasn’t unreasonable, but I believe that this entire event needs to be rethought and studied more. I believe that these famines had a volcanic factor and are possibly some of the deadliest volcanic-induced famines on record. We have evidence of a large eruption taking place sometime in 1694-1695, right before the coldest years of the decade. The eruption is extremely overlooked, so I can’t give any specifics on just how big it was, but it looks to have been a little more than half the size of Tambora based on the ice cores. In any case, this eruption wouldn’t have to be that large to cause a devastating volcanic winter, as the climate was already cold before the eruption even happened. Candidates have been put forth, with Hekla and Serua being the most discussed, but I doubt either of them was responsible. They erupted too early and were too small to cause the sulfate spike, even if we were to assume these eruptions were extremely rich in sulfur. These eruptions could’ve caused some minor cooling preceding the eruption but definitely not the famine.

Almost nothing is known about UE 1695 except that it was a tropical eruption and is in the top 25 eruptions of the past 2500 years. This eruption is in my top 10 underrated eruptions of all time, but it doesn’t compare to my n. 1. What if I told you that the 13th century could’ve seen not 1 but 2 VEI 7s? You might be surprised, but this is actually a strong possibility. This eruption had the unfortunate luck of taking place a little less than 3 decades before the aforementioned eruption of Samalas and was massively overshadowed.

“Azuma Kagami” states that on June 9th (currently July 27th) there was a lightning strike in Kaneko-go, Musashi Province, and at the same time it was said that hail fell and that white snow fell in Makita-so, Mino Province. It was reported that frost had fallen across the country on July 16th, and it was described as almost like winter weather.'' On the evening of August 6, a flood occurred, washing away riverside residences and causing many drownings. Furthermore, on August 8, the area was hit by a typhoon, and theAzuma Kagami” records that “the leaves of the plants and trees withered, and it felt like winter was on the horizon. All the crops were lost.” Regarding the winter of the same year, ` “Meigetsuki” reports that it was a mild winter, with ears of wheat sprouting, cherry blossoms blooming, and crickets chirping.

Kagami would paint an even more horrid picture for Japan in the Kanki famine of the 1230s, the worst famine in the nation’s history. 1,000,000-2,000,000 people, or about a third of the entire country’s population, died. In 1230, Japan was smashed by frosts and freezes almost the entire year, ironically, barring winter. Floods and windstorms were commonplace, making agriculture almost impossible. In 1231, the weather would change from cold and wet to hot and dry. The people had resorted to eating the seeds, and it would take years to restore the economy as well as agriculture. Social order broke, and human trafficking was made legal. Parents sold themselves and their children into slavery. in desperation, and people fled to the cities and flung themselves into servitude.  The cities were full of the dead and dying, making fertile conditions for disease. No soul would escape the scent of death, and even the shogun would despair at the horrible conditions. Russia would suffer a large famine at the same time, and England would experience a terrible famine in 1235 that may or may not have been related. Anomalous weather was noted across the globe at this time. These events were likely caused by an eruption taking place sometime in 1229 or 1230; a large tropical eruption produced a similar sulfate load to the Tambora eruption. Some studies have the eruption larger and some smaller, but it was definitely bigger than the 1695 eruption and the 1809 eruption.

Another potential mystery, VEI 7, for our records just proves that we don’t know much about our historical volcanic record. In fact, half of the largest eruptions in the past 2500 years came from unknown sources, including the largest eruption of them all, the 426 B.C. eruption. All of these eruptions are thought to be firmly within the VEI 6 range, with some likely reaching into VEI 7 territory. I am a very cynical person, but I have a hard time believing that scientists would miss so many recent major eruptions. Beyond the absolute basics, we have no idea where ME 536, 1230, and 1695 took place. Maybe our methods are just that ineffective, or maybe these eruptions weren’t all that big. It is possible that these sulfate spikes weren’t caused by VEI 6s but by VEI 5s. As you already know, not all volcanoes have the same gas budget; some eruptions will be sulfur-rich, and some will be sulfur-poor. It all depends on the geology of the volcano, and areas in the world bring forth some extreme cases. The most well-known is the 11,500 BC eruption of Laacher See; despite being just a little larger than the Pinatubo eruption, it produced at least 4x as much sulfate. Around 80-160 teragrams, to be more precise. Let’s not forget that Pinatubo was a sulfur-rich eruption in its own right! In my opinion, it would be disingenuous to assume that this is the only eruption of recent times with such a high sulfur budget. The 2011 Nabro eruption produced around 3-4.5 teragrams of SO₂ despite being an average VEI 4. In fact, all of the largest sulfur releases in the past 20 years were from VEI 4 eruptions; the eruptions of Sarychev Peak and Kastochi were extremely rich in sulfur. The Tonga eruption, despite being more than 100x larger than these eruptions, produced 10x less sulfur. It would be disingenuous with these facts and precedents to say that a VEI 5 can’t be the size of some mystery eruptions.

I’ve seen some incredulity when it comes to associating these famines with eruptions, and I can’t help but wonder why. Volcanism is one of the most important climate variables, being capable of overwhelming extreme amounts of greenhouse gases and freezing most of the earth. It doesn’t make any sense that these large eruptions played an insignificant role in these famines. In order to argue against my case, one would have to explain how these large explosive eruptions failed to produce meaningful climate effects, which is a tall order. These eruptions were big enough, were in the right location, and happened at the right time to either cause or significantly exacerbate these famines. I would say it would be harder to argue against my case since there is no evidence of any climate events that would negate the cooling from the eruption. Quite frankly, I honestly believe the fact that something as geologically insignificant as a VEI 6 caused or played a major role in apocalyptic famines is too scary of a fact for some to accept. If natural variability and ENSO could cause a devastating famine, then there is no reason VEI 6 can’t. After all, the geologically insignificant Pinatubo eruption produced a significant drop in global temperatures, despite a moderate El Niño happening around the same time.

As it stands, our community has made great strides in uncovering the unknown events of the last 2000 years. Samalas, Ilopango, Okmok, and Zavaritskii have been uncovered, with the unidentified eruptions of 536-540, !108-1110, and 1808/9, gaining the most attention The aforementioned eruptions and subsequent winters are fascinating but not uncommon. An eruption potentially exceeding the sulfur load of Samalas in 426 BC, the potentially empire-ending eruption of 626 AD, and the enigmatic !458 anomaly. Even more minor but still significant mysteries, so many that I won’t even bother to list them all. Even more elusive incidents lie deep in the bowels of the Holocene. It is pleasing to say that there is much work to be done!

Tallis, February 2026

Further reading on the 1695 weather in Scotland