How can refreezing water beneath a glacier lift its upper layers?

Refreezing water beneath a glacier can increase the glacier's total mass and physically alter its structure. When water at the base of a glacier refreezes, the process adds new material to the bottom of the ice mass. This addition of mass at the base exerts an upward force that tends to lift and displace the upper layers of the glacier. This phenomenon, which has been observed in various Antarctic ice fields such as the Dome A plateau, demonstrates that glaciers can grow not only through surface accumulation but also through basal accretion.1