Strength-temperature relationships for first-year, second-year and multi-year sea ice

• Main Author: Johnston, M. E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: The International Society of Offshore and Polar Engineers 2019
• Subjects: temperature; borehole strength; first-year; secondyear; multi-year; sea ice; Sea ice
• Online Access: https://nrc-publications.canada.ca/eng/view/object/?id=821af9b4-dbeb-4b12-b2d2-7ab186b90536; https://nrc-publications.canada.ca/fra/voir/objet/?id=821af9b4-dbeb-4b12-b2d2-7ab186b90536

Strength-temperature relationships are presented for four categories of ice: first-year ice (FYI), second-year ice (SYI), young multi-year ice (yMYI) and thick multi-year ice (TkMYI). The equations are based upon the borehole strengths (BHS) measured during 876 tests in 162 boreholes. The strength of every type of sea ice decreases with increasing ice temperature. FYI and SYI are governed by nearly identical BHS-temperature relations for overlapping temperatures in the range -10°C to 0°C, but it is also important to note that SYI can be expected to deteriorate about one month later than FYI. The BHStemperature relations for yMYI and TkMYI are similar over the temperature range -9°C to -2°C. Factors other than ice temperature affect ice strength, so it is to be expected that equations based solely upon ice temperature cannot reproduce the BHS exactly. The BHS was overestimated for 56.8 to 69.4% of tests performed at individual test depths and 61.1 to 72% of the depth-averaged BHS for individual boreholes, depending upon ice category. Cold ice produces the lowest relative errors in strength, and warm porous ice the highest relative errors in strength. Peer reviewed: Yes NRC publication: Yes