CSI Rivers: Fluvial fingerprints of tectonic activity
Bedrock rivers carve the surficial pattern of valleys and ridges that characterizes fluvial terrains in high mountains. When tectonic forces act on the upper crust of the Earth and cause it to deform, the surface of the Earth, which is the upper boundary of the crust and the river valleys that are imprinted in the crust take part in the deformation. We have some understanding of how tectonically induced deformation reshapes the long profile of rivers and the map pattern of fluvial drainage networks, but can we solve the inverse problem of inferring rates and modes of deformation from the shape of drainage networks? In this talk I will review two field cases: one from the Basin and Range province in the US where rivers are used to infer temporal variations of tectonic uplift rates, and the second from Mount Lebanon where a suite of rivers is used to infer rates and modes of horizontal deformation along the Dead Sea fault system.