The Ayles ice Shelf, one of a number of key ice masses in the Arctic, has been found to have broken free from land; as noted in the wikipedia:

“The Ayles ice Shelf was one of six major ice shelves in Canada, all located on the northern coast of Ellesmere Island, Nunavut. The ice shelf broke off from the coast on August 13, 2005, forming a giant ice island 37 metres (120ft) thick and measuring around 9 miles by 3 miles in size (approximately 66 square kilometers or 25.5 square miles in area). The oldest ice in the ice shelf was believed to be over 3,000 years old. The ice shelf was located at (83°1.5′N 77°33.5′W), approximately 800 kilometers (497 miles) south of the North Pole.”