264 R. S. TARE RECENT ADVANCE OF GLACIERS IN ALASKA 



tended at least as far up the valley as we had gone the previous summer, 

 and from. one side of the valley to the other. By the crevassing, the con- 

 centric moraines northeast of the interior flat vs^ere completely destroyed, 

 the ridges being replaced by a imiforni maze of jagged ice pinnacles. 

 Some of the moraine still clung to the flatter portions of the broken ice, 

 but most of it had tumbled into the crevasses. In consequence of these 

 changes a large measure of clear ice appeared where, in 1905, only mo- 

 raine was seen when viewed from a distance. Thus the appearance of the 

 glacier was as totally altered as its condition. 



In addition to this breaking, there has been a decided thickening of the 

 lower portion of the advancing glacier, so that it now rises between 200 

 and 300 feet higher than it did in 1905 (compare figures 1 and 2, plate 

 10). The margin has also advanced seaward and encroached somewhat 

 on the interior flat; but the advance has not disturbed the ice platform 

 of the flat, nor of the moraine-covered area outside of it. Exactly how 

 much of an advance there has been can not be stated, since we have no 

 exact basis for measurement, though, so far as could be told from compar- 

 ison of photographs, it seems to be certainly not less than 200 yards. The 

 forward movement has caused the ice to override and bury the granite 

 gorge which was visible in 1905 (plate 10), and the forward thriist has 

 so completely destroyed the system of subglacial drainage that a stream 

 no longer emerges from this part of the glacier. Instead, a large stream 

 now issues from the eastern side of the glacier, descending through a 

 marginal channel which in 1905 carried little, if any, water from Varie- 

 gated glacier. 



By this transfer in position of the glacial stream the rapid building up 

 of deposits in the interior flat has stopped, and the stream emerging from 

 it is greatly diminished in volume. On the other hand, a stream which 

 in 1905 carried waters mainly from Orange glacier is now greatly in- 

 creased in volume and rushes as a violent torrent through a marginal 

 channel cut in the granite more than a quarter of a mile from its course 

 in the previous summer. On emerging from this canyon the stream 

 spreads out over a broad alluvial fan in a series of distributaries. . 



This fan, which is built out into Eussell flord, is very large, and in 

 1905 attracted our attention especially because glacial waters no longer 

 occupied the eastern portion, on which, instead, there was a dense alder 

 growth, with the individual bushes at least twenty-five years old. We 

 interpreted this condition to be the result either of a diminution in 

 volume of the glacial waters or of a transfer in their point of emergence. 

 We little suspected, however, that in ten months this part of the fan 



