FIGURE 2.2 The accumulation rate of ice in Greenland was low during the Younger Dryas, and both the start and end of the period show as abrupt changes. Modified from Alley et al. (1993).

Ice cores from other sites, including Baffin Island, Canada (Fisher et al., 1995), Huascaran, Peru (Thompson et al., 1995), and Sajama, Bolivia (Thompson et al., 1998), show evidence of a late-glacial reversal that is probably the Younger Dryas, although the age control for these cores is not as accurate as for cores from the large ice sheets. The Byrd Station, Antarctica, ice core and possibly other southern cores (Bender et al., 1994; Blunier and Brook, 2001) indicate a broadly antiphased behavior between the high southern latitudes and much of the rest of the world, with southern warmth during the Younger Dryas interval (see Plate 2). The record from Taylor Dome, Antarctica, a near-coastal site, appears to show a slight cooling during the Younger Dryas, although details of the synchronization with other ice cores remain under discussion (Steig et al., 1998). The Southern Hemisphere records are not comparable with those from central Greenland in time resolution; further coring is planned.

The ice-core records demonstrate that much of the earth was affected simultaneously by the Younger Dryas, typically with cold, dry, windy con-



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