For three decades scientist Peter Doran has collected environmental data in Antarctica. This year he is leading a project that uses aerial sensors to probe beneath the surface of vast glaciers. The ice that hangs off the edge of Antarctica and floats on the ocean is melting faster than it is being replenished, even in pockets of East Antarctica typically thought to be less vulnerable to climate change, according to a study published Monday. These structures, known as ice shelves, shed nearly 4,000 gigatons of their mass between 1994 and 2018, according to the new research, which leveraged nearly 25 years of satellite measurements of ice thickness. It echoes findings of numerous previous studies reporting the retreat…