Strength-Temperature Relationships for First-year, Second-year and Multi-year Sea Ice

摘要

Strength-temperature relationships are presented for four categories ofice: first-year ice (FYI), second-year ice (SYI), young multi-year ice(yMYI) and thick multi-year ice (TkMYI). The equations are basedupon the borehole strengths (BHS) measured during 876 tests in 162boreholes. The strength of every type of sea ice decreases withincreasing ice temperature. FYI and SYI are governed by nearlyidentical BHS-temperature relations for overlapping temperatures inthe range -10°C to 0°C, but it is also important to note that SYI can beexpected to deteriorate about one month later than FYI. The BHStemperaturerelations for yMYI and TkMYI are similar over thetemperature range -9°C to -2°C. Factors other than ice temperatureaffect ice strength, so it is to be expected that equations based solelyupon ice temperature cannot reproduce the BHS exactly. The BHSwas overestimated for 56.8 to 69.4% of tests performed at individualtest depths and 61.1 to 72% of the depth-averaged BHS for individualboreholes, depending upon ice category. Cold ice produces the lowestrelative errors in strength, and warm porous ice the highest relativeerrors in strength.