Here we report the recovery of a deep ice core from Dome C, Antarctica, that provides a climate record for the past 740,000 years.For the four most recent glacial cycles, the data agree well with the record from Vostok.The interglacial stage following Termination V was exceptionally long—28,000 years compared to, for example, the 12,000 years recorded so far in the present interglacial period.
In this scenario, annual ice layers would be on the order of metres.
The project is best known for producing records of atmospheric carbon dioxide and methane with high time resolution and dating accuracy.
This was accomplished by collecting and analyzing an ice core from a site named WAIS Divide (79.468° S 112.086° W) that is on the WAIS ice flow divide.
The earlier period, between 740,000 and 430,000 years ago, was characterized by less pronounced warmth in interglacial periods in Antarctica, but a higher proportion of each cycle was spent in the warm mode.
The transition from glacial to interglacial conditions about 430,000 years ago (Termination V) resembles the transition into the present interglacial period in terms of the magnitude of change in temperatures and greenhouse gases, but there are significant differences in the patterns of change.