SEDIMENTARY RECORD OF RAPID CLIMATIC VARIABILITY IN THE NORTH-ATLANTIC OCEAN DURING THE LAST GLACIAL CYCLE

Comparisons between a Greenland ice core isotopic record and marine sediment grey level records of the North Atlantic Ocean show that rapid temperature variations witnessed by the ice core (Dansgaard-Oeschger events) during the last glacial period can also be detected in marine sediments. This shows that the resolution obtained in marine cores can be sufficiently high to record rapid climatic fluctuations. Several spectral analyses of those grey level marine records consistently indicate that significative fluctuations of the climatic response exist with periodicities of 5 to 1 kyr in addition to orbital forcing. These high frequencies are close to those predicted by various dynamic ocean models.