English: The massive Thwaites Glacier, which slides slowly over 74.5 miles (120 km) of coastline in West Antarctica, has been called “Antarctica’s riskiest glacier” due to the impact of the release vast amount of water as it melts. According to a recent publication by the Cooperative Institute for Research in Environmental Science at the University of Colorado Boulder (CIRES), the demise of this ice sheet poses the biggest threat for sea-level rise this century.

The glacier, roughly the size of Spain, has been melting rapidly over the last decades, but the process has not been thoroughly studied. Recently, scientists have discovered the unsettling fact that that warmer water underneath the glacier is causing melting from below, which means the melting is occurring faster than previously anticipated. The enhanced melting also increases the likelihood of the collapse of the glacier—possibly within the next few decades.

At the current melt rate, the glacier currently contributes four percent of annual global sea level rise. Should it collapse, scientists currently estimate that global sea levels would rise by several feet, a scenario that would cause substantial flooding in coastal areas around the world.

Nearly 100 scientists have joined together in the International Thwaites Glacier Collaboration (ITGC) to conduct a five-year collaborative set of studies aimed at collecting instrument data throughout the glacier and adjacent ocean, and then modeling ice flow to predict the future of the Thwaites Glacier. To date, the ITGC has discovered many changes in the ice, the surrounding water, and the area where it floats off the underlying bedrock—insights that will help the understanding and potential mitigation of glacial change in a warming climate.

On January 1, 2022, the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Terra satellite acquired a false-color image of the Thwaites Glacier. This type of image uses infrared and visible light (Bands 7,2,1) to distinguish ice from water and cloud. Deep water appears dark inky-blue or black, while cloud looks white, and ice or snow shows as bright electric blue. Black lines have been overlain on the image to mark the edge of the continent. The brownish swirls appear to be sediment although it is possible the coloration comes from shadows. The long ice tongue of Thwaites Glacier can be seen protruding into the Amundsen Sea.