What was the climate like at Lake El'gygytgyn in the past? The opened sediment cores give a rough idea of the cold and warm periods, but only the results of the many different analyses will allow them to be deciphered. Using state of the art technology, the researchers hope to be able to reconstruct the past in detail over the next two years, and ideally even be able to look at individual years. In Cologne, the core logger measures the so-called magnetic susceptibility – the magnetisability of the material – and the colour spectrum of the cores. Every sediment has its own "fingerprint", an individual combination of density, electrical resistance, sound wave velocity, natural gamma radiation and magnetic properties. What conclusions can be drawn?