Ice that forms as a result of the freezing of water-saturated snow. It commonly forms at the surface of a glacier between the equilibrium line and the firn line, and gives the glacier additional mass.
The blue ice on the surface of this glacier above McMurdo Ice Shelf on Ross Island, Antarctica, is superimposed ice. It was formed by melting of the ice cliff to the left and refreezing in the depression below. Photo M. J. Hambrey, 1995.