268 R. S. TABR RECENT ADVANCE OF GLACIERS IN ALASKA 



(plate 13, figure 1). They moreover reveal the fact that there was an 

 extensive alluvial fan southwest of the alder-covered glacier terminus. 



Condition in 1905. — On our visit to this region in 1905 we were 

 greatly surprised and puzzled* by the fact that Galiano glacier no longer 

 supported an alder thicket (plate 13, figure 2). On investigation we 

 found much wood scattered over the moraine-covered terminus of the 

 glacier, and even battered stumps in place. We were further 

 puzzled by the' fact that the alluvial fan, which shows clearly in Eussell's 

 pictures, was no longer present (compare figures 1 and 2, plate 13). In 

 its plaee there is much moraine, over certain portions of which wood 

 fragments are scattered (plate 14), as- if alder and Cottonwood growth- had 

 been destroyed. The glacial streams now wind through this moraine in a 

 multitude of channels, and their deposits are rapidly burying the 

 morainic hummocks (plate 14). There is every appearance of having 

 been an upward thrust through an alluvial fan, destroying it, throwing 

 down vegetation wherever it grew, and leaving scattered morainic hum- 

 mocks in place of the fan. The signs of this disturbance extend over a 

 bulb-shaped area to a distance of 3 or 4 miles from the visible terminus 

 of Galiano glacier. 



The explanation of such a remarkable change seemed so difficult to us 

 that in our preliminary rejoort we did not discuss it fully. Nevertheless 

 we were even then forced to the conclusion that between 1890 and 1905 

 there must have been a forward thrust of Galiano glacier which broke up 

 a bulb-shaped expansion of the glacier that was buried beneath alluvial 

 fan deposits of the glacial streams. We searched carefully for evidence 

 of buried ice in this area, but found no definite proof of it, although from 

 the larger areas of morainic hummocks there was far more water emerg- 

 ing, and with lower temperature, than could be accounted for by the nor- 

 mal run-off of rainfall. Moreover, there were numerous water-filled pits 

 in the moraine, proving recent sinking, but none in which we could be 

 positive that the settling was still in progress. 



In the light of the observations of 1906 I am convinced that these 

 changes are to be correlated with the changes which were observed in the 

 other glaciers described in this paper, and that a few years ago the 

 Galiano glacier was subjected to a forward thrust similar to that now 

 affecting Variegated, Haenke, and Atrevida glaciers. The effect of this 

 thrust has now died out and the glacier is returning to its normal condi- 

 tion, although as yet the alder has not again taken root on the moraine 

 and the alluvial fans have not yet again buried the moraine of the out- 



* Tan- and Martin : Bull. American Geographical Society, vol. 38, 1906, p. 152. 



