Spatial–temporal heterogeneity in a small lake and its implication for paleoclimate reconstruction

Lakes provide continuous records of past regional and global climate. Most studies utilize single trench section dig from the lake shore margins or from single core in the central part/depocenter of the lakes for paleoclimate reconstruction. These reconstructions are based on the assumption of homogenous sedimentation across the lake. However, single core approach for paleoclimate reconstruction is often debated due to inter-site spatial and temporal variations in sedimentation and proxy responses. Therefore, in the present study, we explored the spatial–temporal heterogeneity in a small post-glacial lake of the Lahaul Himalaya and its influence on paleoclimate reconstruction. The depocenter of lake received ~ 2.5 times higher average sedimentation compared to the shore margin. Despite the distinct sedimentation rate in depocenter and shore margin, environmental magnetic and total organic carbon (TOC) records showed similar environmental signals over equivalent time periods. The depocenter core provided high-resolution lacustrine environment, whereas the marginal trench recorded major shifts in paleoclimate over a longer time scale. New multi-proxy data showed strengthened Indian summer monsoon (ISM) during medieval climate anomaly (MCA) and weakened ISM during little ice age (LIA) in the NW Himalaya.