Figure 3. Possible correlations between millennial scale climate shifts and known volcanic eruptions.

(a) All known very large (M ≥ 7) NH volcanic eruptions with radiometric ages (red circles) shifted within error to previously documented rapid cooling events (blue squares). (b) Known large radiometrically-dated (M ≥ 6) SH volcanic eruptions (red circles) shifted within error to previously documented Greenland warming events (yellow squares). The small grey horizontal arrows in both panels represent the total shift required to obtain a match to an abrupt climate event. All eight NH eruptions occur within error of an abrupt Greenland cooling event, and all five SH eruptions timings are within error of a warming event. Dashed lines with question marks represent abrupt climate shifts possibly linked to yet unidentified eruptions. The label ‘Okataina’ at 33.5 ka BP refers to two distinct eruptions responsible for Okataina Units K and L. The two yellow circles indicate previously published correlations.