Physical properties of the WAIS Divide ice core

Journal of Glaciology
By: , and 

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Abstract

The WAIS (West Antarctic Ice Sheet) Divide deep ice core was recently completed to a total depth of 3405 m, ending ∼50 m above the bed. Investigation of the visual stratigraphy and grain characteristics indicates that the ice column at the drilling location is undisturbed by any large-scale overturning or discontinuity. The climate record developed from this core is therefore likely to be continuous and robust. Measured grain-growth rates, recrystallization characteristics, and grain-size response at climate transitions fit within current understanding. Significant impurity control on grain size is indicated from correlation analysis between impurity loading and grain size. Bubble-number densities and bubble sizes and shapes are presented through the full extent of the bubbly ice. Where bubble elongation is observed, the direction of elongation is preferentially parallel to the trace of the basal (0001) plane. Preferred crystallographic orientation of grains is present in the shallowest samples measured, and increases with depth, progressing to a vertical-girdle pattern that tightens to a vertical single-maximum fabric. This single-maximum fabric switches into multiple maxima as the grain size increases rapidly in the deepest, warmest ice. A strong dependence of the fabric on the impurity-mediated grain size is apparent in the deepest samples.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Physical properties of the WAIS Divide ice core
Series title Journal of Glaciology
DOI 10.3189/2014JoG14J100
Volume 60
Issue 224
Year Published 2014
Language English
Publisher Ingenta
Contributing office(s) Geosciences and Environmental Change Science Center
Description 18 p.
First page 1181
Last page 1198