GISP2 Volcanic Sulfate From 9 to 16 Ka
Periods of greatest warming coming out of the last ice age are contemporaneous with times of sulfate anomalies in numerous contiguous layers (blue circles containing the number of layers). Red bars show sulfate anomalies in individual layers of ice in the GISP2 borehole. The purple line shows the δ18O proxy for temperature adjusted for gas age. The Preboreal warming is contemporaneous with the largest sulfate anomaly observed. The Bølling warming is contemporaneous with the largest number of contiguous layers containing volcanic sulfate. Dryas periods of increased glaciation are contemporaneous with little or no volcanism.