GEOGRAPHY IN THE NEWS:

This article explains current research to understand Thwaites, the world's "riskiest" and "most important" glacier, according to some scientists. "A complex interplay of topography, climatic change and ocean currents have coalesced to make the western regions of Antarctica (where Thwaites is situated) particularly vulnerable. Topography is critical when it comes to the reasons why Thwaites is acutely exposed. Antarctica is often split into East and West – not simply to make the vast continent easier to represent but because there are fundamental differences between the regions. ‘East Antarctica is principally a large continent with mountain ranges and thick ice, but west Antarctica is more like an archipelago of islands – predominantly below sea level and vulnerable to change,’ explains [Andy] Smith [a senior glaciologist at the British Antarctic Survey]. The increased presence of warmer water, carried towards the southern polar regions by ocean conveyors, is exacerbating issues. Usually, the continental shelf keeps the warm water in the deep ocean surrounding the continent. In recent decades, however, more warm water has got over the continental shelf and flowed down towards the ice. If the warm water thins the ice, it also opens up a larger gap underneath the sheet, exposing more of the underlying ice and potentially precipitating an accelerated rate of retreat. Thwaites is of particular interest not only due to its scale and the underlying topography but also due to what it is supporting. ‘Thwaites has access to a massive inland reservoir of ice and so changes to Thwaites could affect the whole ice sheet,’ says Smith. ‘Other glaciers are still important, but they don’t have the same potential to have such a significant impact on sea level rise.’ Ice draining from Thwaites accounts for approximately four per cent of global sea-level rise and the collapse of the glacier could potentially cause global sea levels to rise by up to 80cm." geographical.co.uk/nature/polar/item/3606-investigating-thwaites-the-riskiest-glacier-on-earth