South Georgia Ridge
The South Georgia Ridge marks the northern edge of the Scotia Plate, a boundary that continues east through the Tierra del Fuego archipelago. This is a transform boundary with the South Atlantic Plate to the north. There is a similar transform boundary marked by the South Scotia Ridge, with the Antarctic Plate to the south. Fragments of continental crust, such as Burdwood Bank and South Georgia, seem to have been left behind as South America moved west. The island of South Georgia was named by James Cook in 1775, but may have been sighted as early as 1675. It was a base for seal hunters in the 19th century, and in the 20th century seven whaling stations were established on the more sheltered northern shore. The last of these closed in 1965. North of the South Georgia Ridge lies the Falkland Plateau, an area of thickened ocean crust of moderate depth, and the broad continental shelf off the east coast of South America—the Patagonian Shelf. The Falkland Islands are a continental fragment left over from the breakup of Gondwana and the subsequent opening of the south Atlantic.