As a result of powerful volcanic eruptions large amounts of sulfur dioxide are deposited in ice cores buried deep within the Antarctic. By studying these deposits a team of researchers from Nevada, led by Michael Sigl and Joe McConnell of the Desert Research Institute in Nevada (DRI), they were able to trace with precision the most explosive of these events over the last 2,000 years. Topping the list was placed the eruption of the Indonesian Samalas (Mount Rinjani), in 1257, followed by the event's Kuwae 1452 and Tambora in 1815. With 26 records analyzed in 19 different locations of Antarctica, this is the reconstruction most precise ever obtained. The powerful volcanic eruptions are one of the most significant causes of climate variability past, because of the large amount of sulfur dioxide they emit. This leads to the formation of microscopic particles known as aerosols.
These aerosols reflect more solar radiation to space, and finally cool the global temperature. By studying the levels of deposits of sulfate, the team was able to build a timeline that shows the precise moment when the greatest eruptions took place. The fourth most powerful eruption occurred around 674 AD, probably inherent in the eruption of Mount Churchill in Alaska. On the fifth and sixth, respectively, there may be events in the Rabaul caldera, which took place in 535 and 536 AD The seventh explosion more intense is that of Quilatoa, which occurred in 1280 in the Andes. The eighth strongest eruption occurred in Central America in 450 AD, while the ninth and last place are placed eruption occurred in Iceland in 1785 and a previous eruption of Mount Rinjani. These reconstructions are fundamental to assess the causes of climate change in place, much debated because it attributed to human factors. And 'the culmination of a decade of work with the participation of several research groups. The results were published in the journal Nature Climate Change.