Post LGM Landscape

Reconstructing the evolution of post-LGM landscape and late Lateglacial paleoclimate in Bösbächital

Student : Nicolas Gay

Supervisor : PD Dr. Susan Ivy-Ochs ; Dr. Kristina Hippe

The analysis of Quaternary geology allows to reconstruct and understand the evolution of the recent landscape. However, moraines are not only an evidence of glaciation, but also give important information about the climate. Indeed, the advance and retreat of a glacier are closely linked to change in precipitation and/or temperature. The research in the Bösbächital with ArcGIS and fieldwork gave an insight in the evolution of the valley. Since the LGM, the Bösbächi glacier advanced at least once (with fluctuations) in the valley. Its moraines are still visible today, but the glacier bed has been slowly covered by deposits and eroded by other processes, including scree, debris flows and streams. Periglacial landforms also recall some colder period of the past. The reconstruction of the glacier with ArcGIS allowed to estimate the paleo-ELA with AAR and AABR methods. That lead to an age estimation with the help of the ELA-depression with respect to the LIA-ELA, the moraines should have been created during the late Lateglacial. The paleo-ELA, and paleo-temperature inferred through biological proxies, allowed to estimate the past change in precipitation. It seems to have been 5.7% higher during the late Lateglacial than today, which is consistent with other studies on the same period.