It was roughly mapped by Norwegian cartographers from air photos taken by the Lars Christensen Expedition , 1936 -- 37 .
It was roughly remapped by them in greater detail in 1957 from air photos taken by U.S. Navy Operation Highjump , 1946 -- 47 .
It was roughly mapped by Norwegian cartographers from air photos taken by the Lars Christensen Expedition , 1936 -- 37 , and remapped by them in greater detail in 1957 from air photos taken by U.S. Navy Operation Highjump , 1946 -- 47 .