The Denmark Strait is the strait that separates Greenland from Iceland. The Norwegian island of Jan Mayen lies northeast of the strait. The strait connects the Greenland Sea, an extension of the Arctic Ocean, to the Irminger Sea, a part of the Atlantic Ocean. It is 480 kilometres long. The narrowest part of the strait is 290 kilometres wide and lies between S…The Denmark Strait is the strait that separates Greenland from Iceland. The Norwegian island of Jan Mayen lies northeast of the strait. The strait connects the Greenland Sea, an extension of the Arctic Ocean, to the Irminger Sea, a part of the Atlantic Ocean. It is 480 kilometres long. The narrowest part of the strait is 290 kilometres wide and lies between Straumnes, on Iceland's Hornstrandir peninsula, and Cape Tupinier, on Greenland's Blosseville Coast. According to the International Hydrographic Organization, the dividing line between the Arctic and the North Atlantic Oceans runs from Straumnes to Cape Nansen, 132 km southwest of Cape Tunipier.