A Marine Perspective on Marine Isotope Stage 4
Abstract
We present two compilations of ocean sediment core data from Marine Isotope Stage (MIS) 4 and discuss how these MIS 4 data compare with the Last Glacial Maximum (LGM). Compiled Atlantic benthic δ13C records allow us to identify spatial patterns associated with changes in deep ocean carbon storage and North Atlantic Deep Water formation. Compiled sea surface temperature (SST) records provide estimates of global and regional temperature changes. These data suggest that, during MIS 4, deep ocean carbon storage and global mean SST were very similar to the LGM. Other data indicate that Southern Ocean productivity during MIS 4 was as high as at the LGM. These observations fit the climatic conditions expected to coincide with the low CO2 values of MIS 4. The fact that MIS 4 had smaller ice sheets than the LGM (85 m sea level equivalent compared to 130 m) had relatively little impact on many marine climate proxies, with the notable exception of δ18O. Furthermore, we identify cold climate states similar to MIS 4 during seven of the last eight glacial cycles. The timing of this early cooling varies, occurring 20-50 kyr before each glacial maximum.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMPP31F1719L
- Keywords:
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- 4914 Continental climate records;
- PALEOCEANOGRAPHYDE: 4926 Glacial;
- PALEOCEANOGRAPHYDE: 4946 Milankovitch theory;
- PALEOCEANOGRAPHYDE: 4954 Sea surface temperature;
- PALEOCEANOGRAPHY