John Francis Ropek this nuclear submarine, Ropek was involved in pioneering oceanographic studies under the polar ice cap of the North Pole, resulting in the report "Characteristics of Polar Ice Observed During the 1957 Arctic Cruise of the USS Nautilus" (Defense Technical Information Center 1958). As a scientist he published many technical papers, such as "US Navy Hydrographic Office synoptic and prognostic wave charts" (US Navy Hydrographic Office 1955), and "An Application of Naval Oceanographic Development to Inland Waters" (Defense Technical Information Center 1967). Later, Ropek was deputy director of the prediction division of the Naval Oceanographic Office. Late in life he lived
North Pole will be entirely free of ice in the summer. This may have significant commercial implications; see "Territorial Claims," below. The retreat of the Arctic sea ice will accelerate global warming, as less ice cover reflects less solar radiation, and may have serious climate implications by contributing to Arctic cyclone generation. Polar bears are believed to travel rarely beyond about 82° North owing to the scarcity of food, though tracks have been seen in the vicinity of the North Pole, and a 2006 expedition reported sighting a polar bear just from the Pole. The ringed seal has also been seen at