Operation Highjump–Air operations in the Antarctic ended. From 24 December 1946, six PBM’s, based on seaplane tenders, operated in the open seas around the continent of Antarctica, and from 9 February, six R4D’s operated ashore from the airstrip at Little America. Together these aircraft logged 650 hours on photographic mapping flights covering 1,500,000 square miles of the interior, and 5,500 miles of coastline, or the equivalent of about half the area of the United States and its entire coastline–Atlantic, Pacific, and Gulf coasts combined. More here and here (scroll down).