I.G.Y. Scientists To Make Study Of Ross Ice Shelf

Press, Volume XCVI, Issue 28415, 23 October 1957, Page 7

I.G.Y. Scientists To Make Study Of Ross Ice Shelf

[From DENIS WEDERELL, “The Press” Correspondent with the U.S. Antarctic expedition.]

McMURDO SOUND. Oct. 21. The Ross ice shelf, over which Scott and Amundsen trekked on their epic journeys to the South Pole, will this summer be subjected to an intensive wideranging study by an American team of I.G.Y. scientists. Dr. Albert Crary, the senior United States scientist on the continent, who spent this last winter at Little America—and intends to spend next winter there, too—will leave on Tuesday on a 1200mile traverse from that base, across the shelf to McMurdo Sound, and from here to the foot of the Beardmore Glacier before returning to Little America. It will be March before the traverse is completed. I His team will travel in a small train of sno-cats and weasels, I (‘quipped with cabs for living and I working. With the fuel they can carry their range is estimated to be about 300 miles. It is about 450 miles from Little America to McMurdo Sound, and the train will be supported by airlift throughout. Ski-planes will carry in tractor and cooking fuel, food and mail. Volume of Shelf Tlie principal data sought by the traverse party will be on the mass and volume of the shelf, its hydrological economy, morphology. and structure. The Ross ice shelf is fed by the glaciers which pour down wide valleys in the high mountain chains bordering the Ross sea. Estimated to be from 600 ft to more than 1000 ft thick, it floats on the sea itself, tilling more than half of the great indentation which is the Ross sea.

Scientists are particularly interested in the annual rate of accumulation of ice from the glacial streams and snowfall, the rate and form of annual wastage—principally through icebergs calving along the 500-mile sea front—its internal structure and temperature variations with depth, and Ihe surface movement, whenever it is possible to determine this. Last summer it was suggested that, through the movement of the shelf seawards, the bodies of Scott and his polar party could be expected to reach the shelf edge this season. These were only estimates. Scott and the survivors of the polar trek died 11 miles short of one-ton depot, which was laid out near 80deg south, about 150 miles from the barrier where icebergs are continually breaking off and being carried slowly northward by the cold waters of the Ross Sea. Speed of Movement Captain Martin Nisker. 53rd Squadron, U.S.A.F., Globemastenavigator, today worked out, from material supplied by Dr. James Zumberge. a United States I.G.Y glaciologist, who will this summer make an ice deformation survey at Roosevelt Island about 50 miles from Little America, th.it the bodies of Scott’s party are by now about 50 miles east f f this base and 50 miles from the sea edge of the barrier. On these calculations the bodies should reach the barrier about 40 miles east of Cape Crozier, the eastern jtip of Ross Island, in about anlother 20 years. But this is more a guess than an estimate, as the shelf moves at speeds varying from 2ft to 4ft a day. and its j general trend in this area is unknown. This summer's study of the shell may throw more light on ns movement. But no-one here expects the bodies of Scott and his party to be* recovered Few would want to be party to such a proposal. As Dr. Crary’s traverse party makes its way slowly across the shelf it will make regular halls for scientific research. Pits will be dug 25 feet deep to study the layering of the annual accumulation of snow, and hand augurs will be used to drill 100 feet down to record internal temperatures and structure. Parts of the shelf are believed to be aground, and a study will be made of the depth of water, below the shelf and the subglacial topography. Further studies will determine the sources ot supply of the shelf to deteimine the nature and proportion ot the contribution from the vallej glaciers and other outlets of I inland ice, and from snow ac-|

cumulation on the surface of the shelf proper. Meteorological observations will also be made, to determine the conditions prevailing in different parts of the shelf, their relationship to conditions at neighbouring bases and the heat exchange at the surface of the shelf ice. Although some of the party may be withdrawn in January, as the date for their return to the United States draws near, they will be replaced by members of the 195859 wintering party, so that, with favourable weather,, a full four months’ work in the field will be completed before the end of the summer. Other traverses to be made this summer will be from Byrd Base in Marie Byrd Land, from Ellsworth Base on the Weddell Sea coast and a smaller one from Wilkes Base on the Knox Coast, facing Australia. Except that these latter three will be overland traverses, rather than treks over shelf ice. their programmes will be similar. From these four traverses the most complete geological profiles of the continent yet obtained will be drawn. Studies made as last summer's tractor train wound its way over the shelf and up on to the Rockefeller Plateau from Little America to establish Byrd Base showed that although Marie Byrd Land was 5000 ft above sea level the ice on which it stood was 10.000 ft thick. Similar surprises may be in store this year.