glaciation

A period of between 40,000 and 100,000 years in duration in which the ice and snow masses of the polar ice caps expand toward lower latitudes, covering a significantly large part of the Earth's surface. It is equivalent to a glacial period or an ice age, although there is considerable confusion with the nomenclature used to identify the various typified cold periods (Ice Age). During the Quaternary - a geological period that began 2.59 million years ago - there has been an alternation of glaciations and interglacial periods, the last of which we are currently living through. The onset of a glaciation is due to the combination of certain astronomical factors linked to cyclical changes in a series of Earth's orbital parameters (orbital eccentricity, axial tilt, precession of the equinoxes), apart from solar activity, which causes there to be periods when the Earth receives a smaller amount of energy from the sun, with the resulting cooling. The Serbian geophysicist, mathematician, and engineer Milutin Milanković (1879-1958) put forward a successful theory that explains the Quaternary glaciations in terms of those orbital variations, known in his honor as Milanković cycles.