Scientists recently made a terrifying new discovery under Antarctica's Ice . Using radar technology, they discovered a massive cavity two-thirds the size of Manhattan located under the Thwaites Glacier. The cavity is thought to have been caused by melting ice, which can contribute to sea level rise. This discovery is concerning as it indicates that the glacier is melting faster than previously thought. The cavity is estimated to contain around 14 billion tons of melting ice, which is equivalent to around 0.4 millimeters of global sea level rise.