We use measurements of annual layer thickness in the ice core to estimate past accumulation rates. Because ice flow thins annual layers, ice flow calculations are essential for inferring past accumulation rates.
We use this estimate of thinning to "unstretch" the measured layers and construct an accumulation rate history.
Comparisons of inferred accumulation rates and temperatures reveal the temporal relationship between them.At Summit, Greenland, temperatures and accumulation appear to have been correlated during the early Holocene and then anti-correlated during the mid to late Holocene.