RAMAN-SPECTROSCOPIC STUDY ON THE SPATIAL-DISTRIBUTION OF NITROGEN ANDOXYGEN IN NATURAL ICE CLATHRATES AND THEIR DECOMPOSITION TO AIR BUBBLES

We present the results of Raman spectroscopic scans to determine the N -2/O-2 ratios on different planes through a clathrate in the GReenland fee Core Project (GRIP) deep ice core, in which the two axes of the s cans are perpendicular to one another. The spectra of the individual f ocal planes do not point to fractionation effects of the N-2/O-2 conce ntrations within a clathrate specimen in the range of the precision of Raman spectroscopy. In a second study, the frequency shift of the N-2 and O-2 peaks due to decomposition of a clathrate to an air bubble is shown qualitatively. From their peak integrals, there is no indicatio n of different retransformation rates to air bubbles between the oxyge n and the nitrogen contents of clathrates. The N-2/O-2 ratios we obser ve in clathrates and on clathrate decomposition at different stages ar e retained in our measurements of air bubbles resulting from clathrate decomposition.