National Geographic : 1966 Jan
Afi a\ IIdian Ocean Atlantic Earth's coldest domain harbors the seal named after British navigator James Wed dell, who discovered the Weddell Sea in 1823. Expedition's camp lies on sea ice three miles from McMurdo Station, per manent United States research base. Above and below the ice, scientists study how seals navigate, communicate, breathe, and forage. Submerged hydrophones cap ture seals' "talk" for a tape recorder in the hut; their vocabulary ranges from high trills to low moans. Divers drop through holes on photographic missions. Down be low they face the risk of losing their way and running out of air. Though seals ac cepted the men as seagoing mammals, the equipment aroused their curiosity (below). One Weddell bit a hydrophone; another, hearing a playback of seal sounds, surfaced through the lab hole to see who was talking.