Decay of first year sea ice : A second season of field measurements : Interim report

• Main Authors: Johnston, M., Frederking, R.
• Format: Report
• Language: unknown
• Published: National Research Council Canada 2001
• Subjects: Sea ice
• Online Access: https://dx.doi.org/10.4224/12340939; https://nrc-publications.canada.ca/eng/view/object/?id=5efb5197-64be-4af7-b6ad-e1080ef06688

This report describes a field program that was undertaken to characterize the seasonal ice decay process using a second year of measurements. Ice property measurements were made and a borehole jack assembly was used to measure the in situ confined compressive strength (borehole strength) of the ice. The project was conducted from 14 May to 28 June 2001 during which time the ice thickness ranged from 1.45 to 1.30 m. More than one hundred borehole jack tests were conducted at depths 0.3, 0.6, 0.9 and 1.2 m. No significant ice ablation occurred during the time that the borehole jack tests were conducted. Over the period mid-May to early June, the ice strength decreased by 50% in the top 0.50 m of ice. Measurements showed that the surface layer of ice decreased from a strength of 22 MPa to 10 MPa between mid May and early June. In comparison, the strength in the bottom layer of ice (depth 1.20 m) remained relatively constant (10 to 13 MPa) during that time.