Document Type

Article

Publication Title

Journal of Glaciology

Publication Date

2010

First Page

12

Last Page

19

Issue Number

195

Volume Number

56

Abstract/ Summary

Firn microstructure is accurately characterized using images obtained from scanning electron microscopy (SEM). Visibly etched grain boundaries within images are used to create a skeleton outline of the microstructure. A pixel-counting utility is applied to the outline to determine grain area. Firn grain sizes calculated using the technique described here are compared to those calculated using the techniques of Cow (1969) and Gay and Weiss (1999) on samples of the same material, and are found to be substantially smaller. The differences in grain size between the techniques are attributed to sampling deficiencies (e.g. the inclusion of pore filler in the grain area) in earlier methods. The new technique offers the advantages of greater accuracy and the ability to determine individual components of the microstructure (grain and pore), which have important applications in ice-core analyses. The new method is validated by calculating activation energies of grain boundary diffusion using predicted values based on the ratio of grain-size measurements between the new and existing techniques. The resulting activation energy falls within the range of values previously reported for firn/ice.

Citation/Publisher Attribution

Spaulding, NE, Meese, DA, Baker, I, Mayewski, PA, and Hamilton, GS, 2010, A New Technique for Firn Grain-Size Measurement Using Sem Image Analysis: Journal of Glaciology, v. 56, p. 12-19. Available on publisher's site at: http://www.ingentaconnect.com/content/igsoc/jog/2010/00000056/00000195/art00002

Publisher Statement

© Copyright 2010 by the International Glaciological Society

Version

publisher's version of the published document

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