The article presents an analysis of the expedition results on morphometry and the internal structure of ice ridges. A regression equation connecting the consolidated layer (CL) thickness of ice ridges with the sum of degree-days of frost is proposed. The issue of the CL distribution inside the ice ridge is considered. It is shown that the largest CL thickness is observed in the zone, combining the maximum sail and keel. The averaged porosity distribution by vertical is derived, and the main regularities of its change inside the ice ridge are shown.
Ice ridges are typical large ice features of the Arctic seas. Having a significant mass and being as a rule in constant motion, ice ridges present a potential threat for marine engineering infrastructure. To determine possible loads on offshore facilities and design appropriate protection, it is necessary to know the main morphometric parameters of an ice ridge for a specific region. They are the crest length, sail height and width, keel depth and width, total thickness, porosity (the volume of voids divided by the total volume of the ice feature; hereafter porosity is referred to as macroporosity), consolidated layer (or CL, the part of the ridge in which the ice blocks were frozen into a monolith), thickness, etc. (Alekseev et al., 2001). Figure 1 presents a diagram of an ice ridge. The CL and porosity refer to the internal structure characteristics of ice features, and it is possible to determine them only by using special equipment.