Fracture toughness of ice and firn determined from the modified ring test
Abstract The modified ring test is used to determine the fracture toughness of synthetic, granular, fresh-water ice average density 0.891 Mg m −3 and firn (average density 0.605 Mg m 3 ) from depths between 26 and 27.2 m in the E core of the Greenland Ice Sheet Project II. Average fracture toughness...
| Published in: | Journal of Glaciology |
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| Main Authors: | , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Cambridge University Press (CUP)
1995
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1017/s0022143000016257 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000016257 |
| Summary: | Abstract The modified ring test is used to determine the fracture toughness of synthetic, granular, fresh-water ice average density 0.891 Mg m −3 and firn (average density 0.605 Mg m 3 ) from depths between 26 and 27.2 m in the E core of the Greenland Ice Sheet Project II. Average fracture toughness is 145.7kPa m 2 for the manufactured ice and 108.6kPam ½ for the firn. Comparison between the ice and firn suggests that ice-fracture toughness decreases with decreasing density (i.e. increasing porosity), suggesting lateral and vertical variations in the near-surface fracture resistance of glaciers and ice sheets may be related to firn densification. The modified ring test has many advantages over conventional, notch-based specimens in that complications which arise in notched specimens due to crack-length, loading-rate, notch-acuity and specimen-size effects are irrelevant for a modified ring-specimen geometry. |
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