Antarctica is losing ice quickly, in part because of climate change. Massive calving events, such as the one that formed the Delaware-sized (5,800 square kilometers, or 2,239 square miles) A-68 iceberg in 2017, can destabilize ice shelves and capture the public’s attention. But the infrequency of extreme calving events makes it difficult for scientists to predict them and understand whether they are connected to climate change.