The 2009 eruption of the Sarychev Peak volcano in the Kuril Islands, seen from international space. … (+)
The mysterious location of a giant volcanic eruption that occurred nearly 200 years ago has finally been solved thanks to traces of ash preserved in ice cores.
In 1831, the famous German composer Felix Mendelssohn wrote about the catastrophic weather during his summer trip through the Alps, remarking that “it is as cold as in winter, there is already a thick layer of snow on the nearest hills. The weather remained rainy and cold for the next two years, leading to widespread crop failures, famine in Asia, and first major cholera epidemic in Europe.
Scientists have long suspected that this cold spell was caused by a massive volcanic eruption releasing sulfurous gases and ash into the atmosphere. This volcanic cloud layer reflected sunlight, causing a global cooling of about 1 degree Celsius.
While scientists knew it was a major event, the identity of the volcano responsible remained unknown and has been hotly debated until now.
By analyzing traces of ash preserved in ice cores recovered from Greenland, the authors of a new study produced a chemical fingerprint of the lava, matching it to a volcano on a remote island halfway around the world.
“Only in recent years have we developed the ability to extract microscopic ash shards from polar ice cores and perform detailed chemical analyzes of them. These shards are incredibly tiny, about a tenth of the diameter of ‘a human hair,’ explains first author Dr. Will Hutchison from the School of Earth and Environmental Sciences at the University of St Andrews in the United Kingdom
Dr. Hutchison and his team were able to precisely date and match the ice core deposits to the Zavaritsky Volcano on the remote and uninhabited island of Simushir, part of the Kuril Islands. The islands today constitute a disputed territory between Russia and Japan.
“We analyzed the chemistry of the ice at very high temporal resolution. This allowed us to determine the precise timing of the eruption back to spring-summer 1831, confirm that it was highly explosive, and then extract the tiny shards of ash. Finding the “The match took a long time and required extensive collaboration with colleagues from Japan and Russia, who sent us samples collected from these remote volcanoes decades ago.”
“The moment in the lab when we analyzed the two ashes together, one from the volcano and the other from the ice core, was a real eureka. I couldn’t believe the numbers were the same. After that , I spent a lot of time delving into the age and size of the eruption in the Kuril archives to really convince myself that the match was real.
The volcano responsible for the 1831 eruption was very remote, but it had a significant global impact on the climate and serious consequences for populations.
Volcanic eruptions can cause severe climate changes depending on the size of the eruption and its location. When a volcano erupts in tropical regions, atmospheric currents parallel to the equator can distribute ash and gases evenly across the globe. At higher latitudes, atmospheric circulation is more complex, as cold air from the poles mixes with warm air from the tropics, much like the volcano’s effect on climate.
Identify the sites of past volcanic eruptions is crucial because it allows scientists to map and monitor the regions of Earth most likely to produce climate-altering volcanic events.
“There are so many volcanoes like this, which shows how difficult it will be to predict when and where the next large eruption might take place,” concludes Hutchison.
The study, “The mysterious eruption of 1831 CE identified as the Zavaritskii caldera, Simushir Island (Kurilles)“, was published in the Proceedings of the National Academy of Sciences and maybe found online here.
Additional material and interviews provided by Andrews University.