A giant iceberg about the size of Delaware that had been under scientists' watch has broken off from an ice shelf on the Antarctica Peninsula and is now adrift in the Weddell Sea. From a report: The 2,200 square-mile, trillion metric-ton section of the Larsen C ice shelf "calved" off sometime between Monday and Wednesday, a team of researchers at Swansea University's Project MIDAS has reported, citing imaging from NASA's Aqua MODIS satellite instrument. Scientists have tracked the crack for more than a decade and they warned in June that the section was "hanging by a thread." Its break, from Antarctica's fourth-largest ice shelf, changes the border shape of the peninsula forever even though the remaining ice shelf will continue to grow. "The iceberg is one of the largest recorded and its future progress is difficult to predict," said professor Adrian Luckman of Swansea University, lead investigator of the MIDAS project. "It may remain in one piece but is more likely to break into fragments. Some of the ice may remain in the area for decades, while parts of the iceberg may drift north into warmer waters."