Experimental Study on Compressive Strength of Sea Ice in the North Pole and High Arctic

During the 13th Chinese National Arctic Research Expedition, the Chinese research team reached the North Pole for the first time aboard the research icebreaker. The sea ice sampling was conducted, and tests were performed to study its physical and mechanical properties. This effort filled a gap in China's experimental data on sea ice in this region. To study the impact of climatic conditions at sampling sites on the compressive strength and physical properties of sea ice, additional sampling and tests were conducted at six other stations between 81°N and 87.3°N. Measurements were taken for the salinity, temperature, and density of the samples to investigate the influence of porosity and brine volume on compressive strength. The data revealed no significant vertical variation in salinity and density in sea ice samples from lower-latitude regions, with similar compressive strengths observed in the top and bottom layers. In contrast, the physical parameters of sea ice in the North Pole region displayed a distinct vertical distribution pattern, with compressive strength showing significant variation along the ice thickness. The results indicate that environmental conditions in different regions significantly affect the uniaxial compressive strength of sea ice. Even at the end of the melting season, sea ice in the North Pole area did not completely melt; its basal layers retained some characteristics of ice from the freezing season, resulting in significantly higher strength compared to fully melted sea ice. Additionally, the study analyzed the impact of transportation on the physical and mechanical properties of sea ice. Under strict low-temperature conditions for transport and storage, no significant differences were observed between field and laboratory test results.