T010-0005
Spatial variability of geothermal heat flux in the McMurdo region of Antarctica constrained by new airborne electromagnetics data
Tuesday, 8 December 2020
Poster
Ricardo Garza Giron, University of California Santa Cruz, Department of Earth and Planetary Sciences, Santa Cruz, CA, United States, Slawek M Tulaczyk, Univ California Santa Cruz, Earth and Planetary Sciences, Santa Cruz, CA, United States, Denys Grombacher, Aarhus University, Aarhus C, Denmark, Nikolaj Foged, Gaborone, Botswana, Neil Foley, University of California Santa Cruz, Santa Cruz, CA, United States, Peter Doran, Louisiana State University, Geology and Geophysics, Baton Rouge, LA, United States, Jill Mikucki, University of Tennessee, Department of Microbiology, Knoxville, TN, United States, Esben Auken, University of Aarhus, Aarhus, Denmark, Krista F Myers, Louisiana State University, Baton Rouge, LA, United States, Ross A Virginia, Dartmouth College, Environmental Studies Program, Hanover, NH, United States and ANTAEM
Abstract:
Geothermal heat flux (GHF) is an important physical quantity that helps understand not only the structures and processes that construe Earth’s upper crust, but also the dynamics of Earth’s cryosphere. The climate sensitivity of polar ice sheets and glaciers may be dependent on the magnitude of heat input from beneath them. GHF plays a role in controlling the variations of the viscosity throughout the ice body, as well as the distribution of melt-water at the base, which, in turn, can reduce the effective normal stresses acting on the ice-rock boundary by increasing pore pressure, leading to the enhancement of basal sliding.
Geothermal heat flux in Antarctica is generally described as having continental-scale variations, with the West Antarctic ice sheet having higher values (>40 mW/m2) than the East Antarctic ice sheet (<40 mW/m2) (e.g. Shapiro and Ritzwoller, 2004; Pollard and DeConto, 2005). However, it has also been shown that local variations in GHF can be large (Fisher et al., 2015). More recently, Foley et al. (2020) presented a method for mapping 10-km-scale variations in GHF on Ross Island, Antarctica, using electrical resistivity obtained from air-borne transient electromagnetics (TEM). In this work, we extend the approach of Foley et al. (2020) to a regional scale by applying their GHF mapping technique to a new data set that covers ~2,000 km of TEM data in the McMurdo Sound, Antarctica, with the goal of acquiring more information on the variability of heat flux in a polar region surrounded by active volcanism and its implications on ice sheets dynamics.
