IceBridge images of crack in Larsen C Ice Shelf Second Pass

Operation IceBridge, a NASA airborne survey of changes in polar ice, recently completed its eighth consecutive Antarctic deployment. This page contains a wrapup video for the entire mission, as well as some footage over the Antarctic Peninsula's Larsen C Ice Shelf, and a few high definition still images. One of this year’s missions flew over a massive rift in the Larsen C. Ice shelves are the floating parts of ice streams and glaciers, and they buttress the grounded ice behind them; when ice shelves collapse, the ice behind accelerates toward the ocean, where it then adds to sea level rise. Larsen C neighbors a smaller ice shelf that disintegrated in 2002 after developing a rift similar to the one now growing in Larsen C. The IceBridge scientists measured the Larsen C fracture to be about 70 miles long, more than 300 feet wide and about a third of a mile deep. The crack completely cuts through the ice shelf but it does not go all the way across it – once it does, it will produce an iceberg roughly the size of the state of Delaware. "It’s a large rift on an ice shelf whose future we are curious about. Inevitably, when you see it in satellite imagery or from a plane, you wonder what is going to happen when it breaks off,” said Joe MacGregor, IceBridge deputy project scientist and glaciologist at NASA Goddard Space Flight Center. "However, large icebergs calve from ice shelves regularly and they normally do not lead to ice-shelf collapse. The growth of this rift likely indicates that the portion of the ice shelf downstream of the rift is no longer holding back any grounded ice.”