Jasper Republican, Volume 1, Number 31, Rensselaer, Jasper County, 16 April 1875 — How Avalanches Are Formed in the Rocky Mountains. [ARTICLE]

How Avalanches Are Formed in the Rocky Mountains.

A Nevada paper, speaking of the avalanches of snow which have been so destructive of life and property this winter, says: “ The purely sliding avalanches, or snow-slides, are such as occur in dry or mere moist snow, while the rolling avalanches take place when the snow is wet or sufficiently moist to form in balls by rolling. The avalanches that occurred in Virginia City were of the genuine rolling description, the kind most dreaded and the most destructive in the valleys of the Alps. A very small beginning when the snow is in the proper condition may end in a destructive avalanche. A ball of snow no larger than a man’s head started high up on the side of Mount Davidson might have swept away several houses at the foot of the mountain. The fearful force of the avalanche was shown here when one broke into a house and killed two men, and another demolished two houses and buried five persons, who were rescued with much difficulty. A further illustration of the terrible force and destructive powers of the avalanche is to be found in the fact that twentyeight Chinamen were killed by one that fell near Genoa. As we have said, a small ball of snow started high up on the slope of Mount Davidson would result in a genuine avalanche. In rolling a distance of fifty yards m the moist snow the small ball of snow would become four or five feet in diameter, when it would burst, and each piece of it would an instant after form a ball of large size; these in turn would explode as soon as they acquired a certain weight and velooity, and a moment after there would be hundreds and thousands of these balls in motion, all bounding down the steep side of the mountain. “ While hundreds of these are exploding or just forming, other hundreds are of full size, and are picking up rocks, dirt and all manner of rubbish, which become involved in the grand downward rush. Toward the lower part of their course the balls become so numerous that they bound and clash together so often that they are broken before they acquire any great size, and the whole avalanche is then a plunging, sliding mass of snow. The avalanche which knocked the houses to pieces and buried five persons started but a few hundred yards above where the houses stood. It started at a bunch of rocks which projected fifteen or twenty feet above the general surface of the slope of the mountain. On these rocks the snow had fallen and accumulated to the depth of about three feet, hanging in places as snow is seen to do on the eaves of a house. From one of these rocks fell a bunch of snow, which began to roll down the hill, and the result was a destructive avalanche. Doubtless the avalanche which killed two men started in much the same way.”