EXPERIMENTAL STUDY ON COMPRESSIVE STRENGTH OF SEA ICE IN THE NORTH POLE AND HIGH ARCTIC

During China’s 13th Arctic Scientific Expedition, the research team reached the North Pole for the first time via icebreaker and conducted sea ice sampling and physical-mechanical property tests, filling a gap in China’s experimental data for this region. To investigate the influence of climatic conditions on sea ice compressive strength and physical properties, ice samples were collected and tested at six additional stations between 81°N and 87.3°N. The salinity, temperature, and density of the samples were measured to analyze the effects of porosity and brine volume on compressive strength. The data revealed that for sea ice from lower latitudes, salinity and density showed no clear variation along vertical profiles, and the compressive strengths of surface and bottom layers were similar. In contrast, sea ice at the North Pole exhibited distinct patterns in physical parameters along the vertical direction, with compressive strength varying significantly across the profile. The results demonstrate that environmental conditions significantly affect the uniaxial compressive strength of sea ice. Even during the end of melting season, the sea ice at North Pole’s was not entirely in a melted state; the bottom layer retained characteristics of freezing-period ice, resulting in notably higher strength than fully melted ice. Additionally, this study analyzed the impact of transportation on sea ice’s physical-mechanical properties. Under strict low-temperature storage and transport conditions, field and laboratory test results showed no significant differences.