SHRINKING ICE

Evening Star, Issue 21934, 22 January 1935, Page 11

SHRINKING ICE

GLACIERS OF SWITZERLAND Switzerland's glaciers are shrinking* They have been shrinking ever since 1922, and last year's figures, recently given out by Professor P. L. Mercanton, director of the Swiss Meteorological Office, indicate that the shrinkage is not only being maintained, but seems to be accelerating, writes Clair Pmc in the ‘ Daily Mail.' So far as it goes, this tends to confirm glaciologists in their theory that glaciers move in great cycles ot alternate advance and retreat extending over periods of, roughly, thirty-five years each. If this theory is correct, the glaciers of the Alps should continue retreating until 1957, when another great cycle ol advance should set in. One might easily assume that it would be a hopeless task to cope with the confusion of movement which is always at work Sn the snout of a huge glacier. There would be no snout at all if it were not for the fact that the glacier has descended to an altitude at which it thaws more rapidly than it renews itself. In the winter, when its thaw stops or is greatly retarded, it pushes on down at its rate of an inch, a foot, or a couple of feet a day. In the summer, more rapidly than its rate of advance can renew it, the snout retreats un. til another winter gives it a chance. SIMPLE WORK. Always, on top of this ceaseless con. fusion of movement, there are the great cycles of alternate advance and retreat which the glaciologists are attempting to chart in the theory which they call the Bruckner theory. But to the glaciologist this'is simple enough. The end of winter is the time of the maximum seasonal advance, and therefore the moment for the annual measurement to be taken. Professor Mercanton. in the collected 1933 measurements which he has now announced, tells us that the great Allalin glacier, east of the Rimpfischhoni above Zermatt, retreated 30ft last year. The Fiesch glacier, to the east of the Eggishorn above the Rhone Valley, re. treated 33ft. The Trient, the northern, fmost glacier of the Mont Blanc range, retreated 48ft. while the Oberaar ana Unteraar, in the vast nest of glaciers to the east of the Jungfrau, retreated 93ft and 162 ft respectively. Of the total of 100 Swiss glaciers which were measured, four were at » standstill, fifteen were advancing, and eighty-one retreating. Ten years ago the annual measurements indicated that, of the same 100, twelve were at * standstill. twenty-tFo were advancing, and sixty-six retreating. The 1933 measurements accordingly fit into the Bruckner theory as nicely as those of ten years ago do, but glaciologists do not yet regard this theory of thirty-five-year cycles of alternate* ad. yance and retreat as definitely established. _ A century of glacier measure, raents in the Alps seems to support it, but glaciology moves so slowly that it takes more than a mere century to establish a new glacial law. The glaciologists are able to tell u% that the Alpine glaciers had a maxi* ttiura of advance between 1810 and 1825, and another maximum along toward! 1855, after which they all retreated. About 1875 a slight tendency to. wards advance reappeared, they say, among the glaciers of the Chamonix region, and worked gradually eastward, expiring in the Swiss Alps in 1893 and in the Tyrolean Alps in 1901.

Meanwhile, a more marked advance was setting in. and it was not until 1922 that it passed its peak and de. scended into the present cycle of retreat.