Measuring stable isotopes of hydrogen and oxygen in ice by means of laser spectrometry: the Bølling transition in the Dye-3 (south Greenland) ice core

Abstract

Abstract We report on the first application of a new technique in ice-core research, based on direct absorption infrared laser spectrometry (LS), for measuring 2 H, 17 Oand 18 O isotope ratios. the data are used to calculate the deuterium excess d (defined as δ 2 H– 8δ 18 O) for a section of the Dye-3 (south Greenland) deep ice core around the Bølling transition (14 500 BP ). the precision of LS is slightly better than that of most traditional methods for deuterium, but not for the oxygen isotopes. the ability to measure δ 17 O is new and is used here to improve the precision of the δ 18 O determination. Still, the final precision for δ 18 O remains inferior to traditional isotope ratio mass spectrometry (IRMS). Therefore, deuterium excess was calculated from a combination of the LS and IRMS isotope determinations.