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Show and timing of climate regimes in both records ( Fig. 5). There are five North Atlantic cold regimes centered at 13.6, 12.7, 12.0, 11.3, and 10.6 kyr and five western US dry regimes centered at < 13.9, 13.0, 12.2, 11.3, and 10.5 kyr. While the errors associated with our age model (± 500 yr) make it impossible to demonstrate absolute synchroneity between the two records, it is clear that both records attest to a similar number of large and abrupt climate oscillations during the Last Glacial Termination. 8180(°/ oo) - 42 - 40 - 38 - 36 - 34 30 AQ 25 20 15 5180(°/ oo) VSMOW Fig. 5. 8180 record for core OL84B. D, through D4 are relatively " dry" intervals; W, through W4 are relatively wet intervals. The timing of the Oldest Dryas ( OD1)/ B0lling ( B): Older Dryas ( OD2)/ Aller0d ( A): Younger Dryas ( YD)/ Holocene boundaries and the Inter- Aller0d Cold Period ( IACP) are based on ice- layer counts from GISP2- Cold intervals in the ice- core record and dry periods in the Owens Lake record are indicated by black/ gray intervals. In summary, we have presented an array of isotopic data from three Great Basin lakes that support the hypothesis that between 52.5 and 9.8 kyr North Atlantic cold events ( for example, the Younger Dryas) occurred during western US dry intervals ( for example, D3); whereas, Atlantic region warm events ( for example the B0lling) occurred during western US wet intervals ( for example, W2a). The last wet phase ( W4) occurred during the last Greenland warm peak. With the advent of the Holocene, linkage of North Atlantic and western US climate regimes weakened and perhaps disappeared. Prior to the Holocene, relatively dry western US conditions occurred when the North Atlantic region was relatively cold. During the early and middle Holocene this relationship was reversed; that is, the western US was relatively dry and the North Atlantic region was relatively warm. |