St Andrews Researchers Solve the Mystery of the Missing Volcano

Once a mystery, the location of an 1831 volcanic eruption has finally been discovered thanks to researchers from the University of St Andrews School of Earth and Environmental Science.

The findings, published in the journal Proceedings of the National Academy of Sciences, detail how the researchers used samples including “well-dated ice cores and stratigraphic records” — records which produce a timeline of strata, and archaeological remains — to pinpoint the location of the eruption.

As explained by lead researcher, Dr William Hutchinson, “The polar ice cores capture the ash and aerosol fallout from major volcanic eruptions […] We were able to chemically analyse these shards and after lots of searching we narrowed the source region down to Japan and the Kurils.” After this, Hutchinson stated: “We finally got some ash samples from Simushir Island and were able to analyse these in our labs at St Andrews and make the connection between the volcanic source and the ice core deposits.”

The group’s research led them to Zavaritskii Caldera on Simushir Island, an extremely remote volcano found in the Kuril Islands between Japan and Kamchatka. Using their data, the researchers were able to match microscopic tephra from the ice cores to deposits from a more recent eruption by Zavaritskii. Other volcanoes had been nominated as candidates for the location of the mystery eruption, such as the Babuyan Claro volcano in the Philippines and the Ferdinandea volcano near Sicily, but they were dismissed as no firm supporting evidence could be found.

Dr Hutchinson remained ecstatic about the discovery: “I had a wonderful moment in the lab when I found that the volcanic ash from the ice core perfectly matched the volcanic ash from Simushir island. I couldn’t believe the numbers were identical!”

The research was an international effort; the team at St Andrews collaborated with scientists from Japan and Russia. “It was great to work with international colleagues and for St Andrews to lead this major research project. When I wrote my grant proposal back in 2019, I dreamt of making exciting discoveries like this, and so it’s just wonderful to have it come full circle,” Dr Hutchinson stated.

The 1831 eruption had a long-ranging impact. The team argues that this volcano is the cause of the climate cooling between 1831 and 1833CE. Dr Hutchinson shared: “In the years following 1831 we can see that Northern Hemisphere temperatures dipped by about 1°C. This cooling doesn’t sound like much but remember that humans are desperately fighting to keep Earth’s temperature from rising by 1.5°C due to anthropogenic climate change.” The cooling had catastrophic consequences; Dr Hutchinson shared that it “lasted a couple of years, but it likely had a big impact on crop yield and food production, and there are reports of major famines in Japan and India with thousands of fatalities.”

Although the cooling was recorded, there was no explanation for the phenomenon, as no record of the volcanic eruption itself was ever made.

“Even today it is estimated that only a hundred people live within 100km of this volcano. It seems that no one was around to record this massive eruption, and hence why it went undiscovered for so long.”

Today, the island is mostly uninhabited. It was previously used by the Imperial Japanese Army as a garrison during World War II, and afterwards as a secret submarine base by the Soviet Navy.

Dr Hutchinson emphasised the importance of the team’s research: “This work really underscores the need for more fundamental volcanic research and monitoring in the remote Kuril Islands. It also underlines the need for a coordinated international community to kick in when the next big one happens. This coordinated community doesn’t exist but, in my opinion, is urgently needed.”

While the 1831 eruption had such a massive impact on the climate, “no one is monitoring it,” Dr Hutchinson exclaimed. He explained that having a coordinated community would be invaluable: “There are so many volcanoes like Zavaritzkii and so it shows how difficult it will be to predict where and when the next large magnitude eruption might come from.”

Image by Oleg Dirksen