StRATEGy - Reconstructing past climatic changes from lacustrine deposits in NW Argentina
Lacustrine sediments provide essential insights into decadal to millennial-scale climate variability and its driving mechanisms. Lake basins are natural sediment traps and thus geo-archives that continuously record environmental and climatic evolution. Our new analytical approaches allow for deciphering the timing and dynamics even of very rapid climate changes and extreme hydrometeorological events causing short-term catchment runoff at seasonal resolution. In this project we investigate sediment records of two lakes located in the complex transition zone between the South American Monsoon system and the northernmost influence of westerlies in NW Argentina. Our study lakes, Laguna Comedero in the Eastern Cordillera at 2035 m a.s.l. and Laguna Peinado in the Puna Altiplano plateau at 3760 a.s.l., are characterized by large differences in present-day precipitation.
The main scientific goals and questions of this project include (1) investigating centennial and decadal-scale oscillations in moisture availability and their causes and (2) testing the hypothesis that changes in climatic boundary conditions can cause changing frequencies of extreme meteorological events. To achieve these goals, we have taken sediment cores and catchment samples form Lakes Comedero and Peinado. Our ongoing high-resolution sediment analyses include micro-facies analyses on thin sections, high resolution (200 micron) XRF element scanning, organic and inorganic carbon determination, stable oxygen and carbon isotope analysis on carbonates, mineralogical analyses, and AMS-C14 dating.
