Speleothem record from Pentadactylos cave (Cyprus): high-resolution insight into climatic variations during MIS 6 and MIS 5

An improved understanding of medium and short-term changes in temperature and rainfall in the East Mediterranean is necessary for a comprehensive description of the regional climate regime. In particular, it can help advancing current climate models and predictions. A new paleoclimate record from Cyprus gives new insights into climatic variations during MIS 6 and 5 for this region. A 66 cm long speleothem from Pentadactylos cave in the Kyrenia range (800 m asl) was extensively dated with the U/Th method and investigated for petrography, fluid inclusions, stable and clumped isotopes. The stalagmite grew from 174.6 ± 0.7 to 112.2 ± 0.5 ka BP. The growth rate varies from 31 to 5 mm/ka during the early-MIS6 and evolving from 123 to 18 mm/ka at the end-MIS6. The onset of MIS5e is marked by a high growth rate (125 mm/ka) until growth decreased drastically after 122 ka. Growth rate and stalagmite diameter as well as δ18O and δ13C curves are positively correlated. We interpret the δ18Oc signal as being controlled by effective infiltration and thus rainfall amount. Climate conditions during early-MIS6 were highly variable (δ18Oc) on a millennial-scale with several short-lived wet episodes during sapropel 6. From 141 to 132 ka, δ18Oc suggests general dry/cold conditions with low bio-pedological activity, followed by a growth stop during H11. The δ18O values during the Eemian wet period in Cyprus are driven by the source effect (sapropel 5). Stable conditions during MIS 5e were rather short: ~2 ka, as shown in the δ13C signal. After 122 ka, a slow deterioration of the soil cover coupled with low rainfall amounts during the glacial inception period show rather a regional decoupling phase. Fluid inclusions show a clear shift (4-5‰) in δ18Ow between end-MIS 6 and MIS 5e. Clumped isotopes measurements indicate kinetic effects between calcite and water of up to ~1‰. After correction for kinetics using Δ47, an estimate for the MIS6-5 temperature shift in the East-Mediterranean is >10°C.