Undocumented Volcano Contributed to Extremely Cold Decade from 1810-1819

South Dakota State University researchers and their colleagues elsewhere in America and in France have found compelling evidence of a previously undocumented large volcanic eruption that occurred exactly 200 years ago, in 1809. The discovery helps explain the record cold decade from 1810-1819.

Researchers made the finding by analyzing chemicals in ice samples from snow-capped Antarctica and Greenland in the Arctic. The year-by-year accumulation of snow in the polar ice sheets records what is going on in the atmosphere.

"We found large amounts of volcanic sulfuric acid in the snow layers of 1809 and 1810 in both Greenland and Antarctica," said Professor Jihong Cole-Dai of SDSU's Department of Chemistry and Biochemistry, the lead author in an article published Oct. 25, in the scientific journal Geophysical Research Letters.
Cole-Dai said climate records show that not only were 1816 -- the so-called "year without a summer" -- and the following years very cold, the entire decade of 1810-1819 is probably the coldest for at least the past 500 years.