Remember the 18-mile-long canyon that was discovered by NASA at the Pine Island Glacier in Antarctica? Their researchers just completed the three-dimensional mapping of all its surface with stunning detail, using Digital Mapping System photographs over Airborne Topographic Mapper data.
You're looking at Pine Island Glacier in Antarctica. It pushes more ice to the sea than any other glacier in the world. See that gigantic 18-mile-long canyon? That's the birth point of a new gargantuan iceberg, larger than New York City.