In late August 2016, sunlight returned to the Antarctic Peninsula and unveiled a rift across the Larsen C Ice Shelf that had grown longer and deeper over the austral winter. Satellites spotted it in natural-color imagery. By November, the arrival of longer days and favorable weather made it possible for scientists to take a closer look.
These photographs show close and wide views of the rift from the vantage point of NASA’s DC-8 research aircraft. NASA scientist John Sonntag snapped the photos on November 10, 2016, during an Operation IceBridgeflight. The mission, which makes airborne surveys of changes in polar ice, completed its eighth consecutive Antarctic deployment later that month.
The rift in Larsen C measures about 100 meters (300 feet) wide and cuts about half a kilometer (one-third of a mile) deep—completely through to the bottom of the ice shelf. While the rift is long and growing longer, it does not yet reach across the entire shelf. When that happens, Larsen C will shed an iceberg about the size of Delaware.
Cracks and calving of ice from the front of an ice shelf are normal. Shelves are fed by glaciers and ice streams coming from the interior of the continent. They advance into the ocean until a calving event takes place. The shelf front retreats and then advances again. The whole cycle can occur over the span of a few decades.