Ice losses from Thwaites Glacier in West Antarctica are currently responsible for roughly four percent of the global sea-level rise.
Ice losses from Thwaites Glacier in West Antarctica are currently responsible for roughly four percent of the global sea-level rise. This figure could increase, since virtually no other ice stream in the Antarctic is changing as dramatically as the massive Thwaites Glacier. Until recently, experts attributed these changes to climate change and the fact that the glacier rests on the seafloor in many places, and as such comes into contact with warm water masses. But there is also a third, and until now, one of the most difficult to constrain, influencing factors. In a new study, German and British researchers have shown that there is a conspicuously large amount of heat from Earth’s interior beneath the ice, which has likely affected the sliding behaviour of the ice masses for millions of years. This substantial geothermal heat flow, in turn, is due to the fact that the glacier lies in a tectonic trench, where the Earth’s crust is significantly thinner than it is e.g. in neighbouring East Antarctica. The new study was published today in the Nature online journal Communications Earth & Environment.
Unlike East Antarctica, West Antarctica is a geologically young region. In addition, it doesn’t consist of a large contiguous land mass, where the Earth’s crust is up to 40 kilometres thick, but instead is made up of several small and for the most part relatively thin crustal blocks that are separated from each other by a so-called trench system or rift system. In many of the trenches in this system, the Earth’s crust is only 17 to 25 kilometres thick, and as a result a large portion of the ground lies one to two kilometres below sea level. On the other hand, the existence of the trenches has long led researchers to assume that comparatively large amounts of heat from Earth’s interior rose to the surface in this region. With their new map of this geothermal heat flow in the hinterland of the West Antarctic Amundsen Sea, experts from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) and the British Antarctic Survey (BAS) have now provided confirmation.
Read more at: Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research
Photo Credit: mystraysoul via Pixabay
