Title: Exploring Earth’s Dynamic Surface with Large Topographic Inversions
Abstract: The Earth’s surface is the active and visible expression of the solid earth system. As such, the topography of the Earth’s surface encodes information about the processes that interact on it, from orogenesis driven by tectonic plates to erosion influenced by orographic precipitation. By describing geomorphic processes using equations borrowed from geophysics, rapid advancements have been made to our ability to extract tectonic information from topography. In this talk I describe work using inverse methods to extract rock and surface uplift from river networks using the stream power incision model. I will show that using topographic inversions can tightly constrain stream power incision model parameters, important for accuratelyinferring rock and surface uplift information. I also show how by incorporating entire river networks into topographic analysis we are better able to discern between scenarios and patterns of uplift that would otherwise be undiscernible using traditional geomorphic analyses. To demonstrate this, I use a case study from the Uinta mountains, Utah. Here, the range shows evidence of topographic rejuvenation, either caused by increased incision due to drainage reorganization, or an increase in the rock uplift rate by any number of tectonic processes. By creating a map of surface uplift from the river networks, examining seismic tomography, using a simple isostatic model, and collating the geological evidence, we show that recent surface uplift is most likely caused by a lithospheric drip.
To join virtually: Zoom
Contact: adam.smith.20@ucl.ac.uk
Recording: Zoom Recording (will be available within a week after the seminar)