Researchers at the Ernest Orlando Lawrence Berkeley National Laboratory have shown that even at temperatures far below those in the Antarctic atmosphere, the surface of solid ice remains covered by a thin film of quasi-liquid water.
Ice has a uniquely low coefficient of friction which is why skaters can glide so swiftly across it.
However, modern methods of testing proved that pressure was not the answer. Now, Berkeley Lab researchers, in collaboration with French and Dutch scientists, have produced the first detailed molecular-scale pictures of the surface of crystalline ice. Water molecules in this surface layer have an unusually high degree of vibrational motion with amplitudes several times that seen in water molecules buried deeper within the bulk of the ice. The high degree of vibrational motion exhibited by water molecules in the surface layers of ice is attributed to the absence of other water molecules above them, together with the weakness of the bonds between water molecules. This not only gives rise to a liquid-like vibrational motion, it also frees the water molecules to interact with other molecules to which they are exposed, such as those in the atmosphere.