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SAKI, LAKE (CRIMEA, UKRAINE) Rhodes W. Fairbridge (Deceased)

Description Located at 45
070 N, 33
33 E near the west coast of the Crimean peninsula in Ukraine, Lake Saki is salty due to the high E:P ratio of the local climate. It has become celebrated in paleoclimatology following a deep boring in the annually layered sediments, which average only 1–2 cm in thickness for each layer (varve). It may be noted that the Swedish term “varve” refers to an annually layered couplet of one dark-colored seasonal layer reflecting low precipitation and one light-colored layer representing the season with higher precipitation. In general, the rainfall intensity varies in phase with that of Central Asia but inversely with respect to Central and Western Europe. A count of the varves by Schostakowitch in 1934 is reproduced in Lamb (1977, Figure 16.24, p. 408), together with a rainfall scale following a suggestion by Brooks (1949). The sequence goes back to 2294 B.C. Due to the thinness of the layers, some may, however, have been lost in the counting, but for long periods, this can be checked by repeat statistical sampling. Time-series analyses have been undertaken by Xanthakis et al. (1995), using several different methods (MESA, or maximum entropy spectrum analysis; Blackmun–Tukey power spectrum analysis; PSA; Fourier FFT; autocorrelation). Interesting clusters of periodicities emerge over the entire series, notably 20–25, 44–46, 57–67, 120–130, and 200–250 years. Similar clustering is seen in long-term analysis of 14C flux levels in ten millennia of tree rings, and in magnetic and auroral records.

An earlier analysis of the Lake Saki varves based on less sophisticated methods by Dewey (1964) recognized a 17 1/3-year cycle, which periodicity he had also identified (with C. S. Jarvis) in flood stages of the River Nile during the first millennium. This periodicity appears to be a beat frequency developed by the two principal lunar tidal parameters, the I8.03-year “Saros” perigee-syzygy period and the 8.849-year apsides cycle, i.e., 17.3769 year. Following the calculations by Brooks (1949, p.299), reproduced as a graph in Lamb (1977), the rainfall at Lake Saki around 2100–2300 B.C. fluctuated around 45–56 cm/year, but for a long interval, 2100 B.C. to A.D. 700, it hovered about 38–42 cm/year; it then rose to a moisture peak of 48 cm/year about A.D. 800, fell, and then rose again to 50 cm/year in 1,100–1,300, falling to 43–45 cm/year till the present. Elsewhere in Russia, Lamb noted a very marked increase in continentality, 1,300–1,450, but after that, it is interesting that Lake Saki displayed no evidence of the Little Ice Age. In general, Lamb notes the Lake Saki record oscillates in an inverse sense to that in western and northern Europe. Particularly, dry spells occurred in the 12th, 10th and 6th centuries B.C. and around A.D. 1250, just when western Europe was particularly wet (Lamb, 1977, p.408). In view of the 21st century interest in extreme events (floods or droughts), the Lake Saki record provides specific data. In the 21