Ice Ages


Ice ages are periods of the Earth's history characterized by glacier advance and cold climate. The response of the Earth's systems to ice ages includes extinctions and migrations of the biosphere, expansion and contraction of oceans and lakes, and the waxing and waning of glaciers.

Keywords: biogeography; climate; glacier; glaciation; interglacial; pleistocene; milankovitch; palaeontology

Figure 1.

Ice age variations on three time scales. (a) Oxygen isotope stages as proposed by Cesare Emiliani (1950). Interglacials are odd‐numbered stages (blue), and have lower 18O/16O ratios. Glacials are even‐numbered (red) and have higher 18O/16O ratios. Stages 3 and 4 are intermediate, but follow Emiliani's original publication, as does the orientation of the y‐axis. The saw‐toothed pattern of the glacial–interglacial cycles is emphasized by the blue line. (b) Oxygen isotope variations of the past 5 000 000 years as recorded in DSDP 846, data provided by Ralf Tiedman. Note the long‐term increase of the 18O/16O ratios, the beginning of the Pleistocene ice age, and 100 000 year periodicity of the last 500 000 years. (c) Older ice ages plotted on a graph of atmospheric carbon dioxide concentration relative to a modern value of ‘1’. Data after Berner (1994).


Further Reading

Agassiz L (1840) Études sur les glaciers. Neuchâtel: Jent et Gassmann.

Berner RA (1994) GEOCARB II: a revised model of atmospheric CO2 over Phanerozoic time. American Journal of Science 294: 56–91.

Broecker WS (1995) The Glacial World According to Wally. Palisades, NY: Eldigo Press, Lamont Doherty Earth Observatory, Columbia University.

Crowley J and North GR (1991) Paleoclimatology. Oxford Monographs Geology Geophysics 16. New York: Oxford University Press.

Emiliani C (1950) Pleistocene temperatures. Journal of Geology 63: 538–578.

Frakes LA and Francis JE (1988) A guide to Phanerozoic cold polar climates from high‐latitude ice rafting in the Cretaceous. Nature 33: 547–549.

Hecht AD (1995) Paleoclimate Analysis and Modeling. New York: Wiley.

Hoffman PF, Kaufman AJ, Halverson GP and Schrag DP (1998) A neoproterozoic snowball Earth. Science 281: 1342–1346.

Imbrie J and Imbrie KP (1979) Ice ages, Solving the Mystery. Hillside, NJ: Enslow Publishers.

Kukla GJ (1977) Pleistocene land–sea correlations. I. Europe. Earth Science Reviews 13: 307–374.

Martin PS (1973) The discovery of America. Science 179: 969–974.

Martin PS and Klein RG (1984) Quaternary Extinctions, A Prehistoric Revolution. Tucson: University of Arizona Press.

Prothero DR (1994) The Eocene–Oligocene Transition: Paradise Lost. New York: Columbia University Press.

Rampino MR, Sanders JE, Newman WS and Königsson LK (1987) Climate History, Periodicity, and Predictability. New York: Van Nostrand Reinhold.

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How to Cite close
Davis, Owen(Apr 2001) Ice Ages. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1038/npg.els.0001635]