What are the Major Ice Ages of the Earths History?
The Earth has experienced at least five major ice ages in its 4.57 billion year history: the Huronian glaciation (2.4 to 2.1 billion years ago), the Sturtian/Marinoan glaciation (710 to 640 mya), the Andean-Saharan glaciation (460 to 430 mya), the Karoo Ice Age (350 to 260 mya) and the most recent Ice Age, which is currently ongoing (40 to 0 mya). The definition of an Ice Age is a long-term drop in global temperatures from the historical norm, accompanied by an extension of continental ice sheets. Each Ice Age is cyclical, generally on timescales of 44,000 and 110,000 years, during which glacial ice rhythmically extends and recedes. The precise causes of historical Ice Ages are unknown, but likely emerged due to a variety of factors, including: positions of the continents, atmospheric composition (greenhouse gases), volcanic activity, the Earth’s albedo (reflectivity), variations in the Earth’s distance from the Sun (Milankovitch cycles), variations in solar output, and asteroid impact
