The process of freezing water in cloud formation. In thunderstorms, glaciation usually indicates strong updrafts and potential for hail. Glaciation is also believed to be required for lightning formation.
A long period of time (10,000+ years) characterized by climatic conditions associated with maximum glacial extent. Compare to " interglaciation" and " stade". Also used to refer to covering of an area by ice: see " glacierize".
The formation, advance and retreat of glaciers and the results of these activities — associated with periods of prolonged cold although not always glacial conditions, and periods of lowered sea levels.
process of growth and spreading of ice sheets and glaciers to cover a major portion of the Earth's land (app. 30% during height of Pleistocene glaciations). Deglaciation is the opposite, the shrinking of ice sheets and glaciers to uncover land areas; the world is presently in an interglaciation in which roughly 10% of the land is ice covered.
A glaciation (a created composite term meaning Glacial Period, referring to the Period or Era of, as well as the process of High Glacial Activity), often called an ice age, is a geological phenomenon in which massive ice sheets form in the Arctic and Antarctic and advance toward the equator. Conversely, the term interglacial or Interglacial Period, such as the current era, is used to denote the absence of large-scale glaciation on a global scale — i.e., a non-Ice Age. Interglacials are, in general, shorter than glacial epochs.