The consolidation of saline ice blocks in water of varying freezing points: Laboratory experiments and computer simulations

摘要

The thermodynamic consolidation of ice rubble in the ridge keel is an important mechanism both in global heat balance and when it comes to offshore structure interaction. Classically, it is considered that consolidation in the keel occurs due to reserved cold at the stage of formation and due to further atmospheric cooling. Such scenario brings consolidation layer thickness to a value of about two times only thicker than the level ice around the ridge, while in-situ observations after summer season show that many ice ridges are almost fully consolidated. The authors propose a thermodynamic process inside ridge keels during the summer season, which may cause the keel to become more consolidated. They assume that fresh water can flow through the keel increasing the freezing point of fluid in the caves, which allows extracting additional cold from the solid ice of the keel and, as a consequence, freezing fluid inside caves. The physical mechanism of possible keel summer transformation in water with varying freezing points was investigated in the laboratory and numerically.