Thwaites Glacier in Antarctica developed a cavity nearly as large as Manhattan

Scientists have discovered a gigantic cavity forming in the Thwaites Glacier in Antarctica. The massive cavity is about two-thirds of the area of Manhattan and is said to be almost 1,000-feet tall and growing. The cavity is growing at the bottom of the Thwaites Glacier in West Antarctica, and the discovery is part of a NASA-led study of the glacier.NASA says that the findings highlight the need for detailed observations of the undersides of Antarctic glaciers as a way to calculate how fast sea levels are rising globally due to climate change. Researchers on the project say that they expected to find some gaps between ice and bedrock at the bottom of the glacier where ocean water can flow in and melt the glacier from below.

However, the researchers say that the size and growth rate of the hole surprised them. They say that the size of the cavity is big enough to have contained 14 billion tons of ice and that all the ice melted over the last three years. Scientists have long thought that the glacier was not attached firmly to the bedrock beneath it.

The data NASA researchers used in the study came from a new generation of ice-penetrating radar used in NASA's Operation IceBridge airborne campaign. Researchers combined the NASA data with data from Italian and German spaceborne synthetic aperture radars. All the data was then processed using a technique called radar interferometry to show how the ground below the surface is moving between images.

Scientists say the size of the cavity under the glacier plays a key role in melting, as more heat and water get under the glacier, it melts faster. Previous numerical models for the melting of the glacier used a fixed shape to represent a cavity under the ice and didn't allow for the cavity to change shape or grow. The new research implies that limitation led to the numerical models underestimating how fast Thwaites glacier is losing ice. Thwaites has enough ice that if it all melted, global sea levels would rise a little more than two feet.