Ross Ice Shelf Rate Of Movement Measured

Press, Volume CV, Issue 30980, 9 February 1966, Page 5

Ross Ice Shelf Rate Of Movement Measured

A glaciologist from Grand Valley State College, Michigan, has estimated that the ice near the seaward edge of the Ross ice shelf, the largest floating ice mass in the world, is moving northward at the rate of about 1800 feet a year, the National Science Foundation has announced. Mr E. Dorrer, leader of a six-man glaciological team that has completed a 570mile, 56-day motor toboggan crossing of the ice shelf, said that the figure was a preliminary estimate based on the apparent movement of aluminium poles placed on the shelf during the 1962-63 Antarctic summer season and remeasured this year. A more accurate determination of the shelf’s movement will not be available until analysis of data is completed. The research project, conducted under the direction of Dr. J. Zumberge, president of Grand Valley State College, is carried out under a grant from the National Science Foundation, which finances and co-ordinates the United States Antarctic research programme. Table-topped Icebergs The northward movement of the ice does not mean that the shelf as a whole is expanding northward since large pieces of the seaward edge frequently break off and float away as giant, tabletopped icebergs. The Ross ice shelf is constantly “fed” from its landward sides by glaciers flowing from Antarctica’s

continent-spanning icecap. The location of the forward edge of the shelf has remained comparatively stable for a number of years. In addition to obtaining information about the movement of the ice shelf, the glaciologists also made studies of snow accumulation, density, and ice strain. The information contributed by the research project may help answer the question of whether the seven million cubic-mile ice sheet which covers the frozen continent is increasing, decreasing, or fairly stable. The existence of the ice blanket governs the present relationship between sea and land in all coastal areas of the world.