2019 CSDMS meeting-073


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The impact of geothermal flux on patterns and rates of glacial erosion

Jingtao Lai, University of Illinois at Urbana-Champaign Urbana Illinois, United States. jlai11@illinois.edu
Alison Anders, University of Illinois at Urbana-Champaign Illinois, United States. amanders@illinois.edu

Glacial erosion has shaped many high mountain belts during the cold periods of the Late Cenozoic. Theoretical models of glacial erosion generally link the pace of erosion to some subglacial properties including basal sliding, basal thermal regime, and effective water pressure. The energy balance of glaciers is a strong control on these properties and therefore, has a potential impact on glacial erosion. Specifically, the geothermal heat from the bedrock can potentially control the patterns and rates of glacial erosion by changing the basal temperature and the supply of meltwater to the subglacial water system. Here, we investigate the impact of geothermal heat flow on glacial erosion using a coupled model of erosion and ice dynamics. The rate of glacial erosion is modeled as a linear function of the basal sliding velocity. The ice flow is modeled using the Parallel Ice Sheet Model (PISM). PISM solves the conservation of energy using an enthalpy-based scheme, and it links basal sliding to subglacial hydrology through a pseudo-plastic basal resistance model. We model glacial erosion over a synthetic glacial landscape using a range of values for geothermal heat flux. Preliminary results demonstrate that higher geothermal heat flux can increase the total amount of erosion significantly by accelerating the rate of basal sliding and expanding the area of sliding into higher elevations.