Spectral Features of 250 kyr Long Lake Van Sediments: Milankovitch Cycles and Their Harmonics

Abstract

Lake Van, which is the largest soda lake of the earth, lies in the Eastern Anatolian High Plateau. Two different composite cores, that span the last 250 kyr and 90 kyr, were drilled in Lake Van within the framework of PALEOVAN project (ICDP). In order to test the theories of quasi-periodic behavior of climate, generated by astronomical and solar forces, this study investigates the cycles in Lake Van sediment geochemistry data by the Lomb-Scargle Periodogram (LSP) spectral method. The results are correlated with the Eastern Mediterranean LC21 sediment core, Soreq and Sofular Cave speleothem stable isotope data with LSP results. The analyses show the presence of the Milankovitch cycles, harmonics of the Milankovitch cycles, Holocene Bond cycles and the Hallstadtzeit solar cycle. However, the results do not give a 1500 year cycle for 11.5-75 kyr BP interval.