​ Ice′bergs. In the polar regions there are masses of ice covering vast fields and streams during all seasons. When the sun is hottest, huge pieces detach themselves from these icefields and glaciers and float into the open sea. These bergs or ​ ​ ​ ​ ​mountains of ice sometimes are more than 250 feet above the sealevel, while the volume of ice below sealevel is about nine times that above. At a distance they have the appearance of dazzling white chalk cliffs of the most fantastic shapes. See Glaciers.