National Geographic : 1892 Mar 21
Glaciers both melt and flow away. evidence to show that the glacier is at present retreating, and that its retreat is quite rapid, viz: The absence of forests in the upper part of Glacier bay, the existence of fresh strie and of glacial debris in situations where the material could not have resisted erosive agencies for any great length of time, the small amount of debris fallen from the mountains on the eastern side of the inlet, the small amount of vegetation on the shore near the glacier, the transverse ridges on the shore, the mass of de tached melting ice in front of the glacier, and, finally, the account of Vancouver, which makes it probable that a large part of Glacier bay was filled with solid ice a hundred years ago.* To these evidences I may add the following observations : On the sides of the mountains bordering the glacier, and especially in the gullies on the northern slopes, there are masses of ice ex tending a hundred feet or more above the present level of the glacier. This ice has been protected from very rapid melting by the debris which covers it. It must have been a connected part of the glacier not many years ago. On the northeastern side of Tree mountain there is a spur which projects into the ice of Main valley. On its upper side and near its end the ice is only some 10 or 20 feet below its top; on the lower side the ice is much lower. Across this spur in a direction parallel to the valley were some small stream beds, beginning abruptly at the upper side, whose source must have been the melting ice when it was level with the top of the spur. The whole spur was covered with bowlders, sand, and some fine detritus. The stream beds were marked only by the disposition of the sand. The fine detritus must assuredly have been washed away by the rain and melting snow if the spur had been uncovered many years. The ice between G and the nunatak to the west is at a higher level than the western or northwestern tributaries and slopes both toward the north and the south. As this region has no 'independent source of supply, it must have obtained its ice from the north western or western tributaries, which therefore must have been at a higher level than they are now. If this subsidence had been due entirely to melting, the surfaces of these two tributaries would not have sunk more rapidly than that of the ice connecting them. We are therefore forced to conclude not only that the ice is melt ing away, but also that it is flowing away. This process- has * Ice Age in North America, 1889, pp. 51-57. 6-NAT. GEOG.MAG., VOt, IV, 1892.
1892 May 15
1892 Feb 19