Unveiling the Enigma: The Volcano That Chilled the Earth in 1831

For almost two centuries, the site of a massive volcanic eruption that occurred in 1831 has remained hidden from researchers, but the enigma has now been unraveled.

The Zavaritskii volcano, located on Simushir Island within the Kuril Islands north of Japan, was identified as the source.

The eruption in 1831 released significant amounts of sulfur dioxide into the sky, which resulted in a global temperature drop of 1˚C. Though this might seem minimal, the cooling led to catastrophic consequences around the globe, with crop failures and widespread famine.

Until recently, the precise position of the volcano was undetermined for nearly 200 years. Some proposed the Philippines, while others suggested Sicily. Nevertheless, conclusive evidence remained absent.

This landmark advancement came from William Hutchison, a volcanologist from the University of St. Andrews in Scotland, who spearheaded the investigation. Unbelievably, the pivotal factor in his team’s findings was ice cores retrieved from Greenland.

Searching for a correlation

“It is only in recent years that we have acquired the capability to extract minuscule ash fragments from polar ice cores and perform thorough chemical assessments on them,” Hutchison mentioned. “These fragments are remarkably tiny, roughly one-tenth the width of a human hair.”

The ice cores revealed remnants of sulfur isotopes, ash particles, and tiny volcanic glass fragments that were dated to 1831. Subsequently, they applied computer simulations to trace the path of the ash particles. They uncovered that the eruption transpired in some area of the northwest Pacific Ocean. Analyzing the deposits alongside geochemical data led them to conclude Japan and the Kuril Islands.

Documentation of past eruptions in Japan is abundant, and no such event was recorded in 1831. This left the Kuril Islands situated between Japan and Russia as the only likely possibility, although they are presently governed by Russia, ownership has historically been contested.

Hutchinson correlated the ash deposits in the ice cores with ash samples from volcanoes throughout the Kurils.

“Locating the match took considerable time and necessitated extensive teamwork with colleagues from Japan and Russia, who provided us with samples collected from these isolated volcanoes many years ago,” Hutchison recounted. “The moment in the laboratory when we compared the two ashes side by side, one from the volcano and one from the ice core, was an authentic eureka moment. I couldn’t believe the results were identical.”

An intense eruption

The eruption of 1831 was so intense that it created the caldera (the sunken basin) that prevails in the volcano today. The cooling effect due to the eruption, combined with three additional volcanic eruptions between 1808 and 1835, likely led to the failure of crops and subsequent famine.

“A key area of ongoing investigation is to determine how much these famines were instigated by volcanic climate cooling versus other socio-political influences,” he stated.

Given its extensive impact, it is peculiar that there are no documented accounts of the eruption. Hutchinson intends to search through Russian and Japanese archives for any documentation of ash deposits or atmospheric variations in 1831.

“The subsequent effort to explore these records genuinely thrills me,” he remarked.