National Geographic : 1947 Oct
Emerging from the Pack at Last, They Sail On Toward the Great Ice Barrier This ring of open Ross Sea water adjoining the frozen continent is due to prevailing ocean currents. been made by planes of the Central Group. Of these, 17 were successful and three partly successful. Nine accomplished very little, be cause of weather conditions or mechanical troubles. The planes spent 220 hours in the air on operational and mapping missions. They flew approximately 27,500 miles, exclu sive of local and test flights (maps, pages 467 and 495). In each plane were mounted trimetrogon aerial cameras. One pointed straight down. Two were pointed downward at angles of 30 degrees from the horizontal, thus sweeping from horizon to horizon. A fourth camera photographed a clock and other recording devices in the plane itself. A fifth camera formed part of the radio altimeter apparatus which, by means of radio pulse echoes, continuously recorded the alti tude of the plane above the ground. Four cameras were operated by an auto matic device which clicked them simulta neously several times a minute, the number depending on the plane's speed and altitude. A plane equipped with such a battery of cameras could photograph in rough fashion about 100,000 square miles-such as a strip 850 miles deep and 70 miles wide both going and coming-under ideal conditions. Following is a resume of the accomplish ments of this group before considering the experiences on individual missions: Several islands in the Ross Sea, which hith- erto had escaped detection because they were buried under the Ross Shelf Ice, were dis covered. The exact location of the east coast of the Ross Sea always has been a mystery, because it rises so gradually in many parts that it is difficult to tell where the sea ends and the land begins under the unchanging white sur face of the never. This expedition found evi dence for determination of several precise points on this shore line. An important project was mapping the Bay of Whales area. The 1947 front of the Ross Ice Barrier was photographed. This barrier changes every year, and maps from previous expeditions when compared with ours will provide valuable data on the movements of a great ice block 400 miles long and 400 miles wide. In the course of this work several new bays, inlets, tension cracks, and crevasses in the barrier were discovered and mapped. The relative rates and directions of ice movements for the central and eastern sections of the shelf were investigated. At least three major mountain ranges hitherto entirely unknown were discovered. Incidental to this was the discovery of at least one, and probably several, mountains of 16,000 to 20,000 feet elevation. These rank easily among the highest moun tains in the world. Precise elevations cannot be determined until photographs are studied.