Duration and structure of the past four interglaciations

Reanalysis and additional dating of the Devils Hole delta(18)O paleotemperature record confirm that the last interglaciation in the Great Basin (the continental analog of marine isotopic substage 5e) lasted similar to 22,000 yr, consistent with the Vostok paleotemperature record which suggests a duration of similar to 19,000 yr for this event in Antarctica. The three preceding interglaciations in the Devils Hole record (analogs of marine isotopic substages 7e, 9c, and 11c) range from 20,000 to 26,000 yr in duration. A similar to 20,000-yr duration for the last interglaciation is consistent with TIMS uranium-series dated sea-level high stands. Thus, the widely held view that interglaciations were of 11,000- to 13,000-yr duration and constituted only about 10% of mid-to-late Pleistocene climatic cycles needs reexamination. The warmest portion of each interglaciation in the Devils Hole time series is marked by a delta(18)O plateau, signifying apparent climatic stability for periods of 10,000- to 15,000-yr duration. (C) 1997 University of Washington.