A volcano in the northwest Pacific Ocean, previously unknown due to limited records, was identified as the cause of a massive eruption in 1831 that cooled Earth’s climate for nearly two decades. The discovery sheds light on the Little Ice Age, one of the coldest periods on Earth in the past 10,000 years.
Researchers analyzed ice cores from Greenland and linked the eruption to an island volcano called Zavaritskii on Simushir Island. This volcano is part of the disputed Kuril Islands archipelago, where Russia and Japan vie for control. The team used geochemistry, radioactive dating, and computer modeling to confirm the link between the 1831 eruption and Zavaritskii.
The eruption, one of the most powerful of the 19th century, released massive amounts of sulfur dioxide into the stratosphere, causing a 1-degree Celsius drop in temperatures across the Northern Hemisphere. The event occurred during the last gasp of the Little Ice Age, which lasted from the early 1400s to around 1850.
The discovery was made possible by analyzing ash and shards of volcanic glass from the ice cores and comparing them with geochemical datasets from Japan and the Kuril Islands. The researchers also used radiocarbon dating to confirm that the samples were within the past 300 years.
The study highlights the importance of monitoring volcanoes in remote areas, as many are poorly understood and can have devastating global consequences. Lead researcher Dr. William Hutchison warned that the next large-magnitude eruption could catch people off guard due to the lack of a coordinated international response.
The findings provide new insights into the Little Ice Age and the role of volcanic eruptions in shaping Earth’s climate. The discovery also underscores the need for better monitoring and preparedness for future eruptions.
Source: https://edition.cnn.com/2025/01/03/science/mystery-volcano-1831-eruption-simushir/index.html