Studies of isotopes and various atmospheric constituents in the core have revealed a detailed record of climatic variations reaching more than 100,000 years back in time. The results indicate that Holocene climate has been remarkably stable and have confirmed the occurrence of rapid climatic variation during the last ice age (the Wisconsin). Delta-O-18 variations observed in the core part believed to date from the Eemian Stage have not been confirmed by other records  including the NGRIP core and are now believed not to represent climate events: the interglacial climate of Eemian Stage appears to have been as stable as the Holocene.
The GRIP logistics were managed by what is now called Centre for Ice and Climate at the Niels Bohr Institute, University of Copenhagen, Denmark. This research centre maintains a web page about ice core research: