Volcanic signatures of the Toba-Eruption (73 ka B.P.) in the EDML ice core (Antarctica) and southern ocean sediment cores: Implications for climate impact and climate teleconnections

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The Toba eruption (73 ka B.P., Indonesia) is the largest volcanic event in the Quaternary period but its sulfuric acid signal so far has only been found in a Greenland ice core. Sulfuric acid aerosols forming by volcanic SO2 in the stratosphere disperse solar radiation and thereby have a significant global cooling effect. Tephras enhance the cooling effect because they fertilize ocean water by introduction of nutrients to the ocean and promote plankton photosynthetic activity, leading to net sink of CO2 due to planktonic fixation of CO2. This project, therefore, seeks to verify the presences of the Toba signal in the EDML ice core (Antarctica) and the Toba tephra layer in Southern Ocean sediment cores to provide essential basic data on an amount of sulfuric acid aerosols and the southward distribution of tephra. These lead to comprehensively evaluate its global impact. It also seeks to verify the presence of common volcanic signals as “tie-points” between Greenland and Antarctic ice cores to synchronize the cores and estimate a phase relationship due to the bipolar seesaw phenomenon.