The article presents an analysis of the expedition results on morphometry and 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 problem of the CL distribution in the ice ridge is considered. Dependence of the CL thickness change on the external ice ridge parameters (sail, keel, total thickness) is determined. 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 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 corresponding protection it is necessary to know the main morphometric parameters of ice ridge for a specific region: crest length, sail height and width, keel depth and width, total thickness, porosity, consolidated layer (CL) thickness, etc. (Alekseev et al., 2001). The latter parameters refer to internal structure characteristics of ice features, and it is possible to determine them only by using special equipment.
In different publications, studies of parameters of ice ridge internal structure are frequently based on rather coarse measurements using mechanical drilling where the internal structure characteristics in the borehole are obtained practically by touch. The need of using more modern equipment to exclude both the objective technical imperfection of the mechanical method of internal structure investigation and subjectivity of the drilling system's operator is noted in (Ervik et al., 2018). Besides, most articles on the internal structure of ice features present observations of single ice ridges - evidence on more than five features is rare (Strub-Klein and Sudom, 2012). Such data paucity is also a result of imperfect methodology.
