Laborative studies of the diffusion rate of stable isotopes in firn
Abstract
The diffusion of stable isotopes of water (d18O and d2H) in ice and firn is a question of interest for ice core glaciology. The back-diffusion (or de-convolution) models used today can be improved by having better knowledge of the diffusivity within firn, and ice. This is a laboratory setup, where we study the diffusion rate of stable isotopes of water within a matrix of fabricated firn. The laboratory procedure is such that two bodies of isotopically different waters are frozen. Flakes are shaved of the ice, making firn grains. The density of this manually fabricated firn is approximately 500 kg / m3. The firn of the two isotopically different waters is then sandwiched in an isolated box held in a freezer. The thickness of the different layers are varied in the stack at the setup, the ice temperature and the ice density are held relatively constant. Samples of the stack are taken over consequent longer time periods. Both d18O and d2H of the water are analyzed, using isotope ratio mass spectrometry. Comparison the results of the diffusion experiment with diffusion models will tell if the measured diffusion rate is similar to theoretical diffusion rates, or not.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2002
- Bibcode:
- 2002AGUFM.C61A..12B
- Keywords:
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- 1610 Atmosphere (0315;
- 0325);
- 1655 Water cycles (1836);
- 1827 Glaciology (1863);
- 1863 Snow and ice (1827);
- 1894 Instruments and techniques