Record of δ^18O and ¹⁷O-excess in ice from Vostok Antarctica during the last 150,000 years

We measured δ¹⁷O and δ¹⁸O in recent Antarctic snow and down the Vostok ice core and calculated the excess of ¹⁷O with respect to VSMOW. The magnitude of the ¹⁷O excess in the Holocene and the last interglacial is ∼45 per meg, and it remains constant in a transect from the coast to the continental interior. Analysis of the transect data shows that the ¹⁷O-excess is not sensitive to temperature variations over the continent. There are significant shifts in ¹⁷ O-excess from low values in glacial to high values in interglacial times. The observed shifts suggest higher normalized relative humidity and/or wind speeds over the source oceanic regions in glacial times.