Volcanic forcing and climate variations during the last glacial period

• Main Author: Flinders, A. F.
• Format: Text
• Language: English
• Published: 2018
• Subjects: geo; envir; Greenland; Kya; Greenland Ice Sheet Project; ice core; Ice Sheet
• Online Access: https://doi.org/10.5194/cpd-8-4941-2012; https://cp.copernicus.org/preprints/cp-2012-123/

Measurements of δ18O in the Greenland Ice Sheet Project 2 (GISP2) ice-core from Summit, Greenland, show repeated temporal variations associated with rapid warming events throughout the last glacial period of the Pleistocene-10–110 kya. The majority of these warming events are preceded in the ice-core record by an increased concentration of insoluble micro-particulate sulfate, indicative of increases in global volcanism. Wavelet analysis of ice-core and marine-sediment records show a repeated 5000–6000 yr periodicity in both volcanic SO4 and δ18O ice records, as well as a 5000–8000 yr cycle in the lithic concentration of ice-rafted debris, atmospheric CO2 concentration, and a database of late Quaternary volcanic eruptions. Increasing concentrations in atmospheric CO2 and CH4 initiated during periods of increased volcanism, peaking during a warm transition, reflect a volcanic-atmospheric-deglaciation feedback, regulated by meridional overturning current-shutdown related cooling.