GLACIER FLUCTUATIONS, SUSPENDED SEDIMENT FLUX AND GLACIO-LACUSTRINE SEDIMENTS

ABSTRACT. In order to perform inverse modelling of climate variability based on palaeoclimate proxy records, the complexity of intermediate steps in the chain of processes from the climate forcing to the responding proxy has to be considered. In reconstructing climate-forced glacier fluctuations from proglacial lacustrine sediments it is important to understand how climate affects glacier dynamics. A glacier system is complex with many factors influencing sediment production, transport and deposition. Fluvial and mass movement processes in the proglacial environment may affect lake sedimentation substantially. We argue that it is easy to over-interpret glaciolacustrine sediment variability by ignoring these complications. The sediment records may contain individual layers resulting from single precipitation or melt events, as well as persistent changes in climate-forced glacier dynamics. We conclude that it is necessary to consider all possible influencing factors in order to derive reliable palaeoclimate data from lacustrine sediment sequences.