Impurity influence on normal grain growth in the GISP2 ice core, Greenland

• Published in: Journal of Glaciology
• Main Authors: Alley, R. B, Woods, G. A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1996
• Subjects: Earth-Surface Processes; Greenland; ice core; Journal of Glaciology
• Online Access: http://dx.doi.org/10.1017/s0022143000004111; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000004111

Abstract Intercept analysis of approximately bi-yearly vertical thin sections from the upper part of the GISP2 ice Core, central Greenland, shows that grain-size ranges increase with increasing age. This demonstrates that something in the ice affects grain-growth rates, and that grain-size cannot be used directly in paleothermometry as has been proposed. Correlation of grain-growth rates to chemical and isotopic data indicates slower growth in ice with higher impurity concentrations, and especially slow growth in “forest-fire” layers containing abundant ammonium; however, the impurity/grain-growth relations are quite noisy. Little correlation is found between growth rate and isotopic composition of ice.