2018 CSDMS meeting-010
Quantitative constraints on landslide frequency through the use of cosmogenic nuclides: a numerical modeling perspective
Quantitative constraints on the frequency of hazards is vital to risk assessments and appropriate mitigation strategies. The frequency of landslides, a common hazard in steep landscapes, is difficult to quantify for a number of reasons including: (1) infrequent occurrence; (2) rapid deterioration of the morphological signature of a landslide event; (3) expensive geochronological approaches are often require to obtain the age of a single event. Through the use of numerical modeling, I propose that more careful approach of using cosmogenic nuclide concentrations of alluvial sediment sourced in landslide dominated drainage basins can alleviate many of these hurdles and provide regional constraints on landslide frequency. This suggestion stems from new development of an old numerical code that quantifies the impacts of landslides on CRN concentrations in alluvial sediment. The modeling shows that quantitative insight can be obtained by measuring CRN concentrations (1) of multiple nuclides (10Be and 14C), (2) of multiple grain sizes (i.e. coarse material sourced from depth in the hillslope), and (3) over time. I will present the new model developments and results as well as discuss some strategies towards applying this in field settings.