Mystery Volcanic Eruption of 1831 Identified After Almost 200 Years

Scientists have successfully pinpointed the origin of a massive volcanic eruption that occurred in 1831, a mystery that persisted for nearly two centuries. The Zavaritskii volcano on Simushir Island, part of the Kuril Islands north of Japan, was responsible for this event, which released significant amounts of sulfur dioxide into the atmosphere, resulting in a drop in global temperatures by approximately 1°C.

Historically, the fallout from the eruption caused widespread crop failures and famines, yet the volcano's exact location remained unidentified, with theories suggesting places as diverse as the Philippines and Sicily. This breakthrough was led by William Hutchison, a volcanologist from the University of St. Andrews, Scotland, whose team analyzed ice core samples from Greenland.

The methodology involved extracting minute ash fragments from the ice cores, where they identified sulfur isotopes and volcanic glass shards dated to the time of the eruption. Through detailed analysis and computer modeling, they traced the ash's trajectory back to the northwestern Pacific Ocean, leading to the conclusion that it was emitted from the Zavaritskii volcano.

Hutchison expressed excitement over the cross-national collaboration that enabled this discovery, which included comparing the ash deposits from the ice core with samples from various Kuril Islands volcanoes. While the eruption's impact was severe, resulting in a caldera formation in the volcano, the absence of any reports or records of the event remains a point of intrigue for researchers.

Future research aims to explore historical records from Russian and Japanese archives to reveal any mentions of the eruption or its atmospheric effects.