The Thwaites Glacier, which is part of the West Antarctic Ice Sheet (WAIS), is the widest glacier on Earth, and has a surface area of about 74,000 square miles, larger than the state of Florida and twice the size of Maine. Thwaites is also sometimes known as the Doomsday Glacier due to the impact it would have on global sea levels if it were to melt completely. It’s thought that sea levels would rise by an average of 25 inches—over 2 feet—across the world if the glacier were to collapse entirely.