HYDROCLIMATIC VARIABILITY DURING HOLOCENE IN THE EASTERN COLOMBIAN ANDES DISCERNED USING HIGH-RESOLUTION LAKE SEDIMENT RECORDS FROM LAGUNA DE TOTA

The South American monsoon (SAM) has major influence over the variability of tropical South American hydroclimate and is the primary source of precipitation in the Colombian Andes. Decadal to centennial variability in SAM and, therefore, hydroclimate of this region during Holocene is less well understood owing to limited availability of high resolution paleoclimate records. In this study, the nature of centennial-multidecadal variability is assessed using lake sediment cores and surface sediments. Sedimentological analyses, including bulk density, percent lithics, grain sizes and magnetic susceptibility are sensitive to hydroclimate and lake levels. The lake sediment cores and surface samples were collected from Laguna de Tota, the largest lake in Colombia, in the Eastern Colombian Andes. The results show changes in variables indicating periods of wet and dry climate during the past 9000 years which show coherence with other available regional high resolution paleoclimate records. The future work will focus on hydrogen isotopic measurements (ẟD_wax) of leaf-wax, constructing a multiproxy record aiming to evaluate the hydroclimate variability. The assessment of decadal to centennial variability in Andean component of SAM is important because water resources fed by the monsoonal precipitation are the major sources of freshwater to the population living in Andean cities.