The number and magnitude of large explosive volcanic eruptions between 904 and 1865 A.D.: Quantitative evidence from a new South Pole ice core

A new volcanic record covering the period of 904 to 1865 A.D. was produced from continuous chemical analysis of a 2001 South Pole ice core. This new record is consistent with previous records in the number and dates of large volcanic events. The relative magnitudes of several prominent events in this new record were compared to the same events in previous records from South Pole and Plateau Remote (East Antarctica) ice cores. The comparison demonstrates that the discrepancies in reported magnitudes of these events are probably a result of the glaciological complications at Plateau Remote, and that volcanic deposit or flux measurements from South Pole ice cores are therefore more reliable parameters of the atmospheric mass loadings of volcanic aerosols. The new record also confirms the previous finding that five large or moderately large volcanic eruptions occurred in the 13t h century. The total atmospheric aerosol mass loadings, inferred from volcanic sulfate flux in this new ice core, from these five eruptions appear to be 3 to 20 times those in other centuries during the last millennium, suggesting a significant role by explosive volcanism in the climatic transition from the Medieval Warm Period to the Little Ice Age.