CLIMATE CORRELATIONS BETWEEN GREENLAND AND ANTARCTICA DURING THE PAST 100,000 YEARS

THE ice cores recovered from central Greenland by the GRIP(1,2) and GISP2(3) projects record 22 interstadial (warm) events during the part of the last glaciation spanning 20-105 kyr before present. The ice core from Vostok, east Antarctica, records nine interstadials during this period(4,5). Here we explore links between Greenland and Antarctic climate during the last glaciation using a high-resolution chronology derived by correlating oxygen isotope data for trapped O-2 in the GISP2 and Vostok cores. We find that interstadials occurred in east Antarctica whenever those in Greenland lasted longer than 2,000 years. Our results suggest that partial deglaciation and changes in ocean circulation are partly responsible for the climate teleconnection between Greenland and Antarctica. Ice older than 115 kyr in the GISP2 core shows rapid variations in the delta(18)O of O-2 that have no counterpart in the Vostok record. The age-depth relationship, and thus the climate record, in this part of the GISP2, core appears to be significantly disturbed.