A Correction

In my article on wind slab avalanches in the July 1947 number of this Journal (p. 70) I expressed surprise at Dr. R. U. Winterhalter’s statement that “slab avalanches occur after many snowfalls without wind.”

A conversation last summer with Dr. Winterhalter made it clear that I had misunderstood him. He uses the word Schneebrett Lawine (snow slab avalanche) to denote an avalanche of snow hardened by any process whatever, whether by wind or other causes, whereas his Windbrett Lawine refers exclusively to what we call a wind slab avalanche. In addition to their formation by wind, snow slabs can develop as a result of accelerated crust building caused by sudden heat; also probably by the freezing of melt water in surface layers. Snow slabs can fall as avalanches under the compulsion of their own stresses, or as wet avalanches owing to the lubricating effects of melt water.

Hitherto the term “snow slab” has appeared little in English writings. Lunn in his Alpine Skiing uses it interchangeably with “wind slab” and I cannot find it mentioned in any other works.

It seems desirable to reconsider our nomenclature on the basis of the generic snow slab and the specific wind slab.