To the untrained eye, Antarctica may look like a giant piece of solid ice that rarely changes, but scientists studying the continent have long known better. The icy surface is dynamic, with glaciers and "streams" of ice flowing toward the ocean.
A slab of ice larger than the continental United States smothers much of East Antarctica. Draining from the East Antarctic Ice Sheet is a river of ice nearly 800 kilometers long. This stream, the Recovery Ice Stream, slides roughly 35 billion tons of ice into the ocean each year.
New elevation measurements will give researchers an unprecedented understanding of the thickness of sea ice, which will be used to help improve climate modeling and forecasts.
In 1984, there were 1.86 million square kilometers of old ice spread across the Arctic at its yearly minimum extent. In September 2016, there were only 110,000 square kilometers of old ice left.