Senckenberg Research

Influences of tipping points on landscape systems

In the work package, the influence of tipping points on geomorphological and hydrological systems is investigated taking the catchment area of the salt lake Orog-Nuur (45°04’N, 100°43’E) in southern Mongolia as an example. The aim is, in particular, the detection of tipping points during the last 25 000 years, which have influenced the local hydrological system. In addition to climatic fluctuations also tectonic events, variations in the dynamics of alluvial fans as well as changes in the dynamics of wind transport of dust, which can lead to shifts in dune areas, are possible triggers of tipping points. Therefore, the Orog-Nuur represents with its catchment area a very variable archive, which is influenced, for example, by earthquakes and large-area landslides. Several earthquakes have affected the study area in the last 100 years and thus decisively controlled the evolution of the lake, water content, water chemistry as well as the upper reaches.

Following a detailed analysis of satellite data and the creation of a geomorphological map in a field campaign sediments are classified according to their genesis with high-resolution remote-sensing methods as well as by ground-penetrating radar (GPR). Furthermore, dating of the deposits by OSL (Optically Stimulated Luminescence) and radiocarbon (14C) as well as the geochemical-sedimentological analyses of the sediments are part of the research. The investigations are used to characterize different types of sediments and, in the best case, to identify their origin (e.g., fluvial, eolian, lacustrine).