Author(s): Ase Ervik; Aleksey Shestov
Keywords: No Keywords
Abstract: The morphological, thermodynamic and mechanical properties of four drifting ridges were investigated in the Arctic Ocean from May 21st to June 23rd, 2015. Temperature was continuously sampled inside the full depths of two of the ridges. A 2-inch mechanical drill was used to establish geometry and macro-porosity. Information on salinity, small-scale strength and temperature was obtained from ice cores. Some measurements were repeated twice for the same ridge, with a time gap of approximately one week between measurements. The average sail height was h avr/sail = 1.9 m, and the average keel depth was ℎ avr/keel = 6.2 m. The average consolidated layer thickness was h mean/cl = 2.0 m, and the average rubble thickness was h mean/ru = 1.7 m. The average sail, consolidated layer and r ubble temperatures were -2.5°C, -2.6°C and 1.8°C, respectively. The average sail, consolidated layer and rubble salinities were 2.7 ppt, 4.9 ppt and 6.3 ppt, respectively. The ridge salinities and shapes suggest that all four ridges were first-year ice ridges. Furthermore, from the continuous temperature measurements, we observed melting from the beginning of June. The ridge areas decreased simultaneously with the temperature increases, the consolidated layer thicknesses increased, and the amount of rubble decreased.