MECHANICAL-PROPERTIES OF RAFTED ANNUAL SEA-ICE

Laboratory constant strain rate uniaxial compression tests were conducted over a range of temperatures, loading orientations, and strain rates on 407 small-scale landfast and rafted annual sea ice samples from Norton Sound, Alaska. This paper documents field ice sample collection, laboratory mechanical properties testing, and the test results. Overall, there was a larger difference between Norton Sound columnar shorefast vertical and horizontal strengths than between columnar vertical and horizontal rafted strengths which is attributed to ice rafting, i.e. differences in the loading direction relative to the c-axis due to tilting of the rafted ice feature from which cores were extracted. Norton Sound rafted and landfast ice sample strengths were generally lower than winter Beaufort Sea landfast ice strengths due to differences in the ice temperature, ice structure, and perhaps other variables. The Norton Sound rafted ice strengths agreed most favorably with Beaufort Sea strengths measured at relatively warm (above sea level) Norton Sound temperatures. Evidence is provided to support the contention that Beaufort Sea and Norton Sound rafted and landfast ice, having similar physical properties and tested under identical test conditions, yield comparable strengths. However, one needs to account for the affects of ice rafting and ice temperature when making this type of comparison and additional tests are needed to statistically support this theory.