The importance of seismic activity for contemporary sediment yields and landscape evolution.

Sediment yield (SY, i.e. the mass of sediments exported by a river per unit of time and per unit of catchment area) is highly relevant for various environmental issues. It is also a key parameter for our understanding of landscape evolution, global nutrient cycles and how humans affect aquatic environments. However, the factors controlling SY are not fully understood. Current models aiming to predict SY mainly rely on empirical relationships between SY and factors describing the topography, lithology, land cover and climate. They do not consider tectonic activity, as it is assumed that its effect is reflected in the topography. Our recent research showed that this assumption does not hold. We found strong correlations between measured SY and the earthquake risk of a catchment and showed that this effect needs to be considered separately from topography when explaining SY. However, the mechanisms explaining this control are not fully understood. This research project therefore aims to better quantify the effects of earthquakes on SY at different spatial and temporal scales and to better comprehend the processes explaining this control. We will especially focus on the role of earthquake-triggered landslides. This role of earthquake-activity will be incorporated in models, which will allow better SY-predictions. Furthermore, we will explore if earthquakes also have a so far unconsidered control on long-term landscape evolution.

Keywords:Tectonic Activity, Sediment Yield, Landscape Evolution, Landslides, Seismic Activity

Disciplines:Forestry sciences