EPSS Colloquium winter-2019

In tectonically active landscapes, both tectonically driven base level changes and bedrock damage can influence the spatial and temporal patterns of erosion. Though the influence of base level changes from differential rock uplift rates on erosion has been examined extensively in previous studies, few studies have examined whether the tectonic influence on bedrock damage may influence landscape evolution. In this talk, I show how tectonic stress interacts with topography and influences landscape evolution by altering the rates and patterns of bedrock fracturing, weathering, and erosion. First, I show how the present-day topographic stress fields influence bedrock fracture patterns in Forsmark, Sweden. The population of existing fractures likely reflects stress history, but the present-day topographic stress field influences the relative abundance of open fractures near the surface and at depths of hundreds of meters. Second, I present my group’s work in the eastern Tibet, which shows that the tectonic control on bedrock damage may explain the measured changes in rock erodibility and landslide characteristics.