We are flying through a massive canyon of ice. And it's not some virtual reality game. This is a 3-D map of a real place. This vast crevasse cuts through a huge, floating plain of ice at the edge of West Antarctica called the Pine Island Glacier ice shelf. And what you're seeing is the first stage in the birth of a huge iceberg. It'll be about 350 square miles – that's about 15 times the size of Manhattan. NASA scientists discovered this icy rift in a kind of happy accident. In October 2011, a NASA team was conducting routine flights over Antarctica to measure changes in the ice. — when they saw this huge crack in the ice shelf. Scientists made this animation from photographs and topographic data taken on that flight. Giant icebergs break off and float away pretty regularly – about every five to ten years, depending on the ice shelf. It's a process called calving. Satellites caught this ice shelf calving giant icebergs in 2001 and again in 2007. But nobody had ever observed or measured this process at such close range. In these images, the icy rift stretches for more than 18 miles. It's about 240 feet across – 820 feet across at its widest point — and almost 200 feet deep. But that's actually only a scratch in the Pine Island Glacier ice shelf, which is enormous: Twelve hundred square miles, and 1600 feet thick. Scientists have observed that the whole Pine Island Glacier is losing mass faster than many scientists thought was possible….and the movement of the entire glacier is also speeding up. When a glacier speeds up, it moves more and more ice OFF of Antarctica and INTO the ocean. That raises sea levels – well, everywhere. In fact some consider Pine Island Glacier to be ‘Ground Zero” for investigations into why West Antarctica’s ice is disappearing. But researchers say this birth of the ice shelf's newest iceberg isn't by itself cause for alarm…really. It’s part of a totally natural cycle. And when this giant iceberg does break away, at least the satellites – and the scientists – will be around to see it. For Our Amazing Planet, I’m Andrea Mustain