Real Climate Records

So far as it goes, this tends to confirm glaciologist in their theory that

glaciers move in great cycles of alternate advance and retreat, extending

over periods of roughly 35 years each.

IF this theory is correct, the glaciers of the Alps should continue retreat-

ling until 1957, when another great cycle of advance should set in.

One might easily assume that it would be a hapless task to cope with the confusion of movement, which is always at work in 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, when its thaw is renewed and it wastes more rapidly than its rate of advance can renew it, the snout retreats until another winter gives it a chance.

Always on top of this ceaseless confusion of movement there are the great cycles of alternate advance and retreat, which the glaciologists are at-

tempting 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.

PROF. Mercanton, in the collected 1933 measurements which he has now announced, tells us that the great Allalin glacier, cast of the Rimptisch horn above Zermatt, retreated 30 ft. last year.

The Fiesch glacier, to the east of the Eggishorn above the Rhone valley, retreated 33 ft.

The Trient, the northernmost glacier of the Mont Blanc range, retreated 48 ft., while the Oberaar and Unteraar, in the vast nest of glaciers to the east of the Jungfrau, retreated 93 ft. and 162 ft. respectively.

Of the total of 100 Swiss glaciers which were measured, four were at a standstill,15 were advancing, and 81 retreating. Ten years ago the annual

measurements indicated that, of the same 100, 12 were at a standstill. 22

were advanclng, and 66 were retreating.

The 1933 measurements accordingly fit into the Bruckner theory as nicely

as those of 10 years ago do, but glaciologist do not yet regard this advance and retreat as definitely established. A century of glacier measurements 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 us that all the Alpine glaciers had a maximum of advance between 1810 and 1825, and another maximum along

toward 1855, alter which they all retreated.

About 1875 a slight tendency toward 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 descended into the present cycle of retreat.