We compared oxygen isotopic profiles from authigenic calcite in nine freeze cores from Lake Turkana, Kenya, with the historical record of lake levels for the past 105 years. Pb-210 dating of the cores indicates that sediment in two of the cores spans the complete historical record. We observed spatial variability in delta(18)O and delta(13)C values between cores and an offset from expected isotopic equilibrium values in several of the cores. Both of these characteristics can be explained by proximity to river input. In model calculations of lake level, we muted the spatial variability of the delta(18)O dataset by using a normalized and stacked record. There is good agreement between the lake level history modeled using the normalized and stacked record and the historical record of lake level. The lake level record derived from the delta(18)O data indicates that lake level fluctuated by 15 m during the last century. Our model calculations indicate that delta(18)O records can be used to generate quantitative lake level curves even using datasets with significant spatial variability.
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