Geothermal Heat Flow Melts the Antarctic Icecap

Different methods, such as remote sensing, climate modelling, studies of ice calving and subglacial hydrology, provide varying estimates of ice loss and the energy balance of the Antarctic ice sheet1,2,3,4. The current study is based on the only constant: the ever-flowing geothermal heat. This heat partially penetrates the ice sheet, while the remainder is trapped beneath it, where it inevitably melts the ice and forms water at its melting point. The melting point of ice decreases with increasing pressure, i.e. the thickness of the ice sheet, reaching nearly -4 ℃ at its thickest point. The calculations performed are based on digital input, which includes data on ice surface temperature5, ice thickness6, and geothermal heat flux7 for areas measuring 20 km x 20 km, covering the Antarctic land area. This is not a simulation, but rather a one-dimensional steady-state calculation based on the annual properties of ice, ice surface temperature, and geothermal heat flux. Here, we present the first temperature map and the melting rate beneath the ice sheet. The amount of heat captured annually is 4082 TWh, which corresponds to an annual melting of 44 Gt or 48 km³ of ice. This represents the "base melting," which remains unaffected by several decades of climate variations.