Peculiarities of consolidated layer growth of the Kara and Laptev Sea ice ridges

UDK: 622.24.085.5

Key words: ice ridge, keel, consolidated layer, porosity, thermal drilling

Authors: V.A. Pavlov, K.A. Kornishin (Rosneft Oil Company PJSC, RF, Moscow), Ya.O. Efimov (Arctic Research Center, RF, Saint-Petersburg), E.U. Mironov, R.B. Guzenko, V.V. Kharitonov (Arctic and Antarctic Research Institute, RF, Saint-Petersburg)

In spring seasons of 2014 and 2015 the Arctic and Antarctic Research Institute according to the contract with Rosneft Oil Company carried out the expedition studies in the Kara and Laptev Sea aimed at determining the morphometric characteristics of ice ridges using hot water drilling methods with recording the penetration rate on computer. Average and extreme values of basic morphometric characteristics of ice ridges such as a sail height, keel depth, total ice thickness, consolidated layer thickness, porosity etc. are obtained for the several investigation areas. Special attention in the paper is paid to the growth of consolidated layer of the ice ridges. The following large-scale spatial regularity is revealed: the thickness of the consolidated layer increases when moving eastwards from area to area. The connection between average thickness of the consolidated layer and total degree-days of frost in separate region is confirmed. Regression equations of this dependence with high level of validity are obtained. This peculiarity is consequence of the effect of gravity and buoyancy forces, under the influence of which the concentration and following compaction of small ice fragments occur nearby the sea level during the ice ridge formation. In general, the most massive consolidated layer corresponds to the areas of the most massive keel.
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