Glacières; or, Freezing Caverns

by Edwin Swift Balch

Professor Israel C. Russell wrote in 1890, about the ice beds on the Yukon: “It is thought by some observers, to be an inheritance from a former period of extreme cold; but under existing climatic conditions, when ice forms beneath a layer of moss, it is preserved during the short summer, and may increase as it does on the tundras, to an astonishing thickness.”

In 1897, Professor Russell says: "It is not probable that all the subsoil ice of northern regions has been formed in one way. Along the flood plains and on the deltas of rivers where layers of clear ice are interbedded with sheets of frozen gravel and vegetable matter, as is frequently the case, it seems evident that the growth of the deposit is due, in some instances, to the flooding of previously frozen layers, and the freezing and subsequent burial of the sediment thus added to their surfaces. When spring freshets spread out sheets of débris over the flood plain of a river, as frequently happens when streams in high latitudes flow northward, the previously frozen soil and the ice of ponds and swamps may be buried and indefinitely preserved." “There is still another process by which frozen subsoil may be formed in high latitudes: this is, the effects of the cold during the long winters are not counteracted by the heat during the short summers. Under the conditions now prevailing in northern Alaska, where the mean annual temperature is below 32° Fahrenheit, the frozen layer tends to increase the thickness from year to year just as the depth of frozen soil in more temperate latitudes may increase from month to month during the winter season. During the short northern summers, especially where the ground is moss covered, melting only extends a few inches below the surface.”

Mons. E. A. Martel, in 1892, wrote of the Creux-Percé: “I incline only, as in all the pits which narrow at the bottom (avens à rétrécissement) to attribute the chilling to the fall of the cold air of winter and to its non-renewal in summer.” And at page 564 of Les Abimes he says: "One knows that evaporation is an active cause of cooling; therefore it is always cooler in caves near the drips of water. * * * I have positively noted this influence of evaporation near the drips of Tabourel (8° instead of 9.5°), of Dargilan, of the Cerna Jama, and in abysses with double mouths where there were strong draughts (Rabanel, Biau, Fosse-Mobile, etc.)." In December, 1897, Mons. Martel writes: “In short, the action of the winter’s cold is the real cause accepted by * * * and recently confirmed by Fugger, Trouillet and Martel.” And also: “It is probable that this influence [evaporation] is only real at rather high altitudes; this is at least what seems the result of the studies of the caves of Naye (1700 to 1900 meters) begun by Professor Dutoit.”

In 1899, Mons. Martel gave an account of the Glacière de Naye. In this paper, he abandons definitely fossil ice, salts and the capillary theory as possible causes of underground ice. He considers that there are four causes: 1, shape of the cavity; 2, free access of snow in winter; 3, high altitude; 4, evaporation due to wind currents. The last two causes he thinks are not necessarily always present. For instance he considers that, at the Creux-Percé, and at Chaux-les-Passavant, the ice is due especially to the sack or hour-glass shape of these hollows where the summer air cannot get in on account of its lightness. At the Glacière de Naye, which is a big windhole, situated at an altitude of 1750 to 1820 meters, Mons. Martel thinks that the ice is formed by the snow and cold of winter, but that its preservation is assured by the evaporation caused by the action of the windhole.

Dr. Terlanday, in 1893, asserted that ice does not form in Szilize in winter, and that the ice first forms in the winter in the upper part of rock fissures and that in the spring, at the time of an increase of temperature, this fissure ice is brought to the melting point by the successive entering of heat into the earth and that it then arrives at the cave, where it aids the formation of icicles. This theory about fissure ice is probably in so far correct, that the ice in the upper parts of fissures, near the surface of the ground, melts before the ice in the lower parts of fissures. The drip would then naturally run into the cave and, as long as the temperature of the cave was low, help to form cave ice.

Dr. Hans Lohmann, in 1895, published some valuable notes about several glacières. While considering the cold of winter as the main cause of the ice, he thought evaporation a secondary cause of cold. He says: "That the cold from evaporation bears its share in cooling a cave, will not be denied. * * * The air saturated with aqueous vapor makes one think of constant evaporation. The aqueous vapor spreads itself by diffusion throughout the entire cave, and if the outside air is driest, goes to that. Through this, more ice and water can always be vaporized, and to the warming elements there is furnished a cooling one. If dry winds get into the cave, then must evaporation be very lively and the chilling especially strong. Through this cause alone can be explained the remarkably low temperature of +6.3° in the new part of the Garischen Stollen, in contrast to the temperature of +7.9° in the old part. The strong draught in the last drew out through its suction the damp air of the new adit, so that there had to be a strong evaporation."

Dr. Lohmann gives some exhaustive notes about prismatic ice. He found it a product of the fall months. He thinks all the observations show that “the beginning of all prismatic formation in the ice may be looked for in the changes of temperature in the cave at the time of the formation of the ice. These cause the everywhere recognized splitting, vertically to the outer surface. The further development hangs, as shown by Hagenbach and Emden, on the attempt of the neighboring cells, to join into larger unities. The increase of the larger crystals is finally prevented by the melting out of the openings between the separate crystals. Through this may be explained the difference in the prismatic ice in different parts of the same cave.”

Regierungsrath Franz Kraus, in 1895, wrote a short essay on glacières in Höhlenkunde. He seems to have seen but few glacières himself, and considers the scientific side of the question by no means solved as yet. He says: “The last word will not be spoken by the geographers and the Alpine climbers * * * but by the physicists, in whose field both questions really belong. Only then, when the physical circumstances of the formation of the ice in glacières have been so thoroughly understood, that under the same circumstances it may be possible to build artificial glacières, only then could one say: the glacière question is definitely settled. The best proof is always experiment.”

He lays down several dicta which he says are universally recognized, among which is this: “2. The ice formations in the débris heaps of basaltic mountains are summer ice formations. The evaporation of the infiltration water is recognized on all sides as the cause of this ice.” I differ in opinion from Herr Kraus about this matter, and think that, on the contrary, every proof shows that the ice of basaltic taluses is not a summer formation and is not due to evaporation.