Pressure changes the melting temperature of ice according to the Clapeyron equation. Ice pushed against an obstacle can melt on its high-pressure side and refreeze downstream where pressure is lower. Conduction of the released latent heat back towards the melting region permits motion around the obstacle. Small obstacles favor this heat-transfer mechanism; larger ones can be bypassed mainly by ice deformation.
Regelation is a physical process that occurs when ice melts under pressure and subsequently refreezes when the pressure is released. This phenomenon is most commonly observed in environments such as glaciers or ice skating, where the pressure exerted by a blade or an object temporarily lowers the melting point of the ice. When pressure is applied to ice, it can cause some of the ice to turn into liquid water, creating a thin layer of water.
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