Ice

Ice is the solid state of water. The great abundance of water on the surface of Earth includes a great quantity of ice in the Polar Regions and high elevations. The relative proportion of each of the three states of water on Earth is a delicately balanced equilibrium controlled by the amount of incoming solar energy and the amount of reflection, known as Aledo, from clouds, water, ice caps, etc. The amount of ice at any one location on Earth varies seasonally, over the long term with climatic change, and even with movements of tectonic plates. One of the most abundant of Earth's substances, ice is especially familiar to residents of high-latitude and alpine regions, and manifests itself in a variety of forms including snow, hail, glaciers, icebergs, and sea ice, along with the artificially produced ice cube. Despite being so familiar, ice and water are anomalous in a variety of respects and behave differently from other materials in a number of important ways. The study of ice, in all forms, and its related processes is known as glaciology.