Linking subaquatic landslide recurrence to evolving slope stability through time
Maddalena Sammartini | UIBK
The PhD is a three-year project in the frame of the European Training Network SLATE (Submarine Landslides and their impact on European continental margin). The project focuses on lacustrine environments and takes into consideration different landslides that occurred in different settings worldwide. The PhD can be divided in two main subjects, strictly linked to each other.
The first part of the PhD focuses on a consistent morphometric characterisation of landslides and the compilation of a lacustrine landslide inventory in different lakes worldwide, in order to study fundamental and/or compare different landslide processes across scales and settings. How and with which morphometric parameters a landslide is measured depends on several factors (e.g. the data availability, the data type, the age of the landslide, the different settings and, last but not least, the operator approach). Hence, there is a need to define a global set of parameters that has to be used to describe, in a consistent manner, different landslides (for instance see Clare et al., in press; and references therein). The use of an unequivocal approach in the interpretation of landslides will provide the basis for robust statistical analysis. This might highlight correlations between several area and volume-related parameters and quantitative links between lacustrine landslide records and different variables that could affect the slope stability (slope geometry, stratigraphy, sedimentation rate, etc). All these information will be compared and used for a better understanding in lacustrine landslide recurrence and evolution. Furthermore, a process of scaling and comparison between lacustrine data and marine data will be carried out in order to define if lakes could be considered as small scale model of marine environment.
For the second part of the PhD, the focus of the work turns from the global dataset to the natural laboratory of Lake Lucerne. Lake Lucerne has been surveyed several times and, therefore, a huge dataset is already available. While previous works focused on geotechnical characterisation of the strata upslope the slide scar, the focus of this doctoral program is to investigate the base of the slope. New geotechnical data will be collected and will be integrated with geophysical and core data. CPT and laboratory test will be used to characterised and compare, from a geotechnical point of view, the different types of landslide (frontally emergent or frontally confined). The correlations that might be found in the local laboratory of Lake Lucerne, will then be compared to the global dataset.