On the limits of Antarctic and marine climate records synchronization: Lag estimates during marine isotopic stages 5d and 5c

Abstract

North Atlantic sediment records (MD95‐2042), Greenland (Greenland Ice Core Project (GRIP)) and Antarctica (Byrd and Vostok) ice core climate records have been synchronized over marine isotopic stage 3 (MIS 3) (64 to 24 kyr B.P.) (Shackleton et al., 2000). The resulting common timescale suggested that MD95‐2042 δ18Obenthic fluctuations were synchronous with temperature changes in Antarctica (δDice or δ18Oice records). In order to assess the persistency of this result we have used here the recent Greenland NorthGRIP ice core covering the last glacial inception. We transfer the Antarctic Vostok GT4 timescale to NorthGRIP δ18Oice and MD95‐2042 δ18Oplanktonic records and precisely quantify all the relative timing uncertainties. During the rapid warming of Dansgaard‐Oeschger 24, MD95‐2042 δ18Obenthic decrease is in phase with δ18Oplanktonic decrease and therefore with NorthGRIP temperature increase, but it takes place 1700 ± 1100 years after the Antarctic warming. Thus the present study reveals that the results obtained previously for MIS 3 cannot be generalized and demonstrates the need to improve common chronologies for marine and polar archives.