Record of δ18O and 17O‐excess in ice from Vostok Antarctica during the last 150,000 years

Abstract

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 17O‐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.