The time series of volcanically produced sulfate from the GISP2 ice core is used to develop a continuous record of explosive volcanism over the past 110,000 yr. 850 volcanic signals (700 of these from 110,000 to 9000 yr ago) are identified
with sulfate concentrations greater than that associated with historical eruptions from either equatorial or mid-latitude regions that are known to have perturbed global or Northern Hemisphere climate, respectively.