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Free keywords:
Antarctica, Geothermal Heat Flow, LAB, Surface Heat Flow, Mantle Heat Flow, Lithospheric Temperatures
Abstract:
In Haeger et al. (2022), we created a three dimensional model of the temperature distribution and the geothermal heat flow of the Antarctic lithosphere as well as a new model of the lithosphere-asthenosphere boundary (LAB). The models were obtained in a three-step approach: First, we calculate the initial temperature distribution in the upper mantle by iteratively combining seismic tomography (An et al., 2015; Schaeffer amp; Lebedev, 2013) and gravity data (Förste et al., 2014; Scheinert et al., 2016) considering composition and density variations self-consistently (Haeger et al., 2019). Second, we define the lithosphere-asthenosphere boundary in a thermal sense based on the resulting geotherm by assuming it corresponds to the 1300°C isotherm. Third, we solve the steady-state heat equation to obtain the temperature distribution and the geothermal heat flow in the lithosphere. One crucial yet still largely unknown factor in the model is the parametrization of the crust. In order to overcome this, we calculated thermal models for a range of crustal properties that are described in detail in Haeger et al. (2022) and the related supplementary material. Here, we only share the conductive temperature and the geothermal heat flow model for the preferred model (n° 29 in the supplementary) in binary netCDF files. Additionally, we present the depth to LAB and surface and mantle heat flow maps, the latter represents the heat flow at the depth of the Moho discontinuity (Haeger et al., 2019) as .txt ascii tables. As a measure of uncertainty of the preferred surface heat flow model, the standard deviation of all calculated models is additionally given. The models are presented in polar stereographic projections with true scale at 71° South (Snyder, 1987) and span ±3700 km with a 10 km spacing in x- and y-direction, respectively. For the netCDF files, the depth ranges from the bedrock surface (BedMachine, Morlighem et al., 2020) which is defined as the 0 level to the LAB in a 1 km spacing. The depths to the Moho and the LAB are given relative to sea level.
