Home – Home – Jornals – Earth’s Cryosphere 2023 number 5

This study is devoted to substantiating the theoretical dependences of the porosity of the unconsolidated part of pressure ice ridges on the distance from the edges of the sail or keel. According to the crushing theory, particle sizes in crushed material follow a lognormal distribution. Ice blocks in unconsolidated parts of ice ridges can be considered as such crushed material. Information on the sizes of ice blocks and voids has been obtained from data on the penetration rate of thermal drilling of ice ridges and grounded ice ridges (stamukhi). It is argued that the average porosity of an ice ridge as calculated from thermal drilling data for a given depth is an estimate of the probability of finding a void at this depth. A statistical model of the depth-wise porosity distribution in the keel and sail of ice ridges as granular media is suggested. The average vertical size of voids decreases with distance from the edge of the keel or sail according to a logarithmic law, and the average vertical size of ice blocks remains approximately the same. The average porosity of the unconsolidated sail and keel changes according to a lognormal law with distance from their edge, and the porosity of the sail is approximately two times less than the porosity of the keel.