A team led by volcanologist William Hutchison from the University of St Andrews has identified an unknown volcano responsible for a significant climate crisis in the Northern Hemisphere during 1831. The eruption released vast amounts of ash and smoke, leading to widespread crop failures and famine.
The volcanic activity was traced back to the Zavaritskii caldera located on Simushir Island in the central Kuril Islands of Russia. This discovery was made possible through the analysis of preserved ash samples found in Greenland's ice.
Hutchison noted that the moment of confirming the ash samples' identity was a pivotal moment in the research. The team established a definitive link between the eruption and the Zavaritskii volcano, determining the age and scale of the eruption.
Prior to this discovery, the origins of the cooling period from 1831 to 1833 were debated, with theories pointing to various volcanoes, including Babuyan Claro in the Philippines and Graham Island in Sicily. However, these were ruled out through chemical analysis.
The research revealed that sulfur precipitation was significantly higher in Greenland than in Antarctica during this period, indicating the eruption's origins were likely in the Northern Hemisphere. The team identified characteristics of a Plinian eruption, similar to that of Mount Vesuvius, and confirmed the connection through microscopic volcanic glass fragments.
The eruption is estimated to have caused a global temperature drop of approximately 1°C, comparable to the effects of the 1991 eruption of Mount Pinatubo. The findings underscore the need for monitoring remote volcanoes that can have global climatic impacts.
Hutchison warned that many such volcanoes exist, complicating predictions of future eruptions that could lead to similar climatic crises. The study highlights the importance of international collaboration in addressing potential volcanic threats to global climate.