Properties of Second-year and Multi-year Ice during Freeze-up

• Main Author: Johnston, Michelle
• Format: Report
• Language: English
• Published: 2004
• Subjects: Arctic
• Online Access: https://doi.org/10.4224/12327562; https://nrc-publications.canada.ca/eng/view/ft/?id=94e0e07c-4821-4a4d-aa49-723cd9325cd9; https://nrc-publications.canada.ca/eng/view/object/?id=94e0e07c-4821-4a4d-aa49-723cd9325cd9; https://nrc-publications.canada.ca/fra/voir/objet/?id=94e0e07c-4821-4a4d-aa49-723cd9325cd9

This report documents results from a field program during which the properties of second-year and multi-year ice were measured during freeze-up, October 2003. This project was undertaken in support of the Arctic Ice Regime Shipping System (AIRSS). Results from this study will be used in considering updates to the methods by which AIRSS accounts for ice decay. The thickness, snow depth, temperature, salinity and borehole strength of ice were measured at six sites in the central Canadian Arctic. Sampled multi-year ice included a one-month old ice cover that consisted of jumbled blocks of old ice (1.0 to 2.4 m thick), a 300 m diameter floe (1.74 to 4.5 m thick) and a 50 m diameter, hummocked floe (more than 2 m thick). Strength of the multiyear ice ranged from less than 1 MPa to 21 MPa, salinities varied from 0.0 to 4.7 艀 and all but the uppermost 0.40 m of ice was at near melting, isothermal temperatures. Measurements were made on one second-year floe, several kilometres in diameter. That floe was from 1.4 to 1.6 m thick, had salinities from 0 to 2.9艀, was characterized by near melting isothermal temperatures and had strengths ranging from 1 MPa to 17.1 MPa. The considerable variability in the secondyear and multi-year ice was ostensibly caused by the small-scale and large-scale voids observed in the ice and the complicated decay process. NRC publication: Yes