National Geographic : 1953 Oct
.. (. i c'i^ S~ii~l i'l' y'llqudr 0s ez\C)X'e~ 'l"i' / 478 Grosvenor's Photographs Enabled National Geographic Cartographers to Pinpoint the Pole What does the North Pole look like? To children it is a candy-striped signpost planted outside Santa Claus's workshop. To cartographers it is a point on the globe, latitude 90° N. To polar navigators it is a position in time and space determined by complex calculations of ground speed, drift, compass errors, elapsed time, and celestial fixes. But to the authors, flying over the Pole at 11:29 a. m . eastern standard time (1629 Greenwich time) on May 20, 1953, it was a particular floe of crystal ice in the vast, ever-shifting pack. Mr. Grosvenor took 15 photographs from the window of the Air Force C-54 as it twice circled the Pole counterclockwise at an average altitude of 7,500 feet (page 476). Painstakingly relating one picture to another by minute comparison of ice floes and open water, he plotted the position and angle from which he had taken each photograph. He was the first to locate the Pole from the air by making photographs from all sides; later, plotting the lines of focus, he found they met at the Pole like spokes of a wheel at its hub. Having thus centered his flight, he concluded that the Pole was at the floe (roughly 2,000 feet wide by 4,000 long) here shown by a circled cross (lower right). Photogrammetric engineer G. C . Tewinkel of the U. S. Coast and Geodetic Survey, asked to check the computations, laid down a perspective grid on the photographs and embarked upon involved mathematical formulae. His conclusion: Mr. Grosvenor was correct. Illustration above shows long line of leads stretching south from the Pole. Low as they appear here, the pressure ridges (white lines) on ice pack are 10 to 30 feet high. They have been thrust up by grind ing floes (page 484). Each grid square in overlay measures 1,000 feet along the side. the other seven and one half, the volunteers who man its three tiny buildings must shift for themselves. They can receive supplies by airdrop, but only in dire emergencies do ski equipped aircraft risk a landing there. From Nord we veered to starboard, cross ing beautiful Independence Fjord (discovered and named by Peary on the Fourth of July 1892) and skirting the northern tip of the vast icecap (page 481). This sheet of fresh water ice, which covers nearly four-fifths of Greenland's 827,300 square miles, is reason enough for the ancient name: "Land of Deso lation," as the English navigator John Davis, called it after his voyage of 1585. But this forbidding island drew seafarers and explorers and colonists to it from the very morning of history. Eric the Red and his Vikings, manning their shallow, 80-foot, square-sailed ships, headed their high prows for Greenland as early as A. D. 983. For 300 years and more Norsemen settled the country some 1,000 miles south of Thule, established nearly 200 townships, prospered-and perished. No man knows even now what struck them down. But by 1400 they were gone, remem bered only as dim figures in the old, heroic sagas. Not till 1576, when Martin Frobisher saw Greenland's southern tip "like pinnacles of steeples all covered with snow," did Euro pean eyes look on Eric's country again. After Frobisher came Davis, and in his wake a trio of English captains-Cunningham, Knight, and Hall-vainly commissioned by King Christian IV of Denmark and Norway to find the lost Viking colonists. A century later came the father of modern Greenland, Hans Povelsen Egede, who founded in 1721 the tiny camp from which Denmark's chain of settlements would slowly grow.