62 ALASKA GLACIERS 



the tidal arrri has raised doubts as to the correctness of 

 the first impression, and I now suspect that it was only 

 the remnant of a former arm of the glacier, stranded as a 

 motionless and slowly wasting summit mass. On the map 

 of the Canadian Boundary Commission (1895) ^ * s re P re ~ 

 sented as a distributary of the glacier. 



At the time of Russell's visit in 1891 the glacier flowed 

 on both sides of the high rock knob (fig. 34) and was re- 

 united beyond it, so as 

 to convert the knob into 

 a nunatak; and it was 

 this conspicuous nuna- 

 tak near the end of the 

 glacier which suggested 

 its name. The retreat 

 of the ice front in the 

 intervening eight years 

 FIG. 34. TIDAL FRONT OF NUNATAK GLACIER, can not have amounted 



Photographed from the north, by D. G. Inverarity, tO leSS than a mile and 

 June 21, 1899. The camera stood on the glacier. . . 



may have been twice as 



great. It was nearly all accomplished in the first half of 

 the period, for the photographs made by the Boundary 

 Commission in I895 1 show a complete separation of the 

 two arms and a close approximation to the condition of 

 1899. The tidal arm was perhaps a third of a mile more 

 advanced in 1895, but the non-tidal was not appreciably 

 longer. It is possible, however, that the latter extended 

 for some distance in a stagnant condition beneath a mantle 

 of drift, for at the time of our visit there appeared to be 

 remnants of ice in a moraine belt stretching for a mile be- 

 yond its extremity. 



The accompanying map (pi. vn) is based on the sur- 

 vey by Gannett in 1899, supplemented by photographs. 

 It is accurate as to the ice front and contiguous land, but 



1 Nos. 20 and 45, on pages 7 and 17 of vol. 17 of the official album. 



