One of the largest icebergs ever recorded has broken off from an ice shelf in western Antarctica, researchers said last Wednesday. The iceberg — about the size of Delaware and weighing an estimated 1.12 trillion tons — finally ripped free sometime between Monday and Wednesday, scientists at the University of Swansea in Britain. Researchers said they were not immediately aware the calving is linked to human-induced climate change. Since the ice shelf was already in the ocean and held a relatively small amount of land ice, the potential melting of the freed iceberg is not expected to have an immediate effect on the sea level.