148 



hundred feet by the powerful erosive action of the expanded 

 glaciers. Between these two ice advances there was a 

 long interval, during which the glaciers receded even 

 farther than at present, and forest growth extended through- 

 out the fiord and even up the valleys now occupied by the 

 glaciers. The last advance terminated only a short time 

 ago, and the recession from this stage of advance was 

 apparently still in progress as late as 1905. The recency 

 of the last advance, and of the ice recession from that 

 stand, is proved by the condition of the vegetation growing 

 in the area occupied by the ice. In the outer portion of 

 the area covered by the expanded glacier, a dense growth 

 of mature alder and some cottonwood covers the overridden 

 gravels, but the growth rapidly decreases in amount and 

 density toward the glaciers. In Seal bay and Nunatak 

 fiord there are only scattered individual plants, and the 

 density of alder growth gradually increases toward the 

 portions of the inlet where the expanded glaciers ended. 

 In other words, this period of ice advance was so recent 

 that only a part of the area is as yet occupied by vegeta- 

 tion, and the outer portion is occupied only by the advance 

 growth of alder and, in the extreme south of cottonwood. 

 The spruce forest of the Alaskan coast has not yet had time 

 to advance upon the region from which the glaciers have 

 so recently receded. 



The date of this second advance is not known, but 

 the vegetation suggests that it was not over a century or 

 two ago. Russell [65] and Davidson [72] have each inter- 

 preted the maps and descriptions of Malaspina and Van- 

 couver as indicating that the front of Hubbard glacier 

 was as far south as Haenke island in 1792 and 1794. Tarr 

 and Martin [26] are not in agreement with this interpreta- 

 tion as to the exact date of the expansion. 



Tebenkof's Atlas of Alaska, [79] however, actually 

 shows the lake in southern Russell fiord, as indicated by 

 a map of Khromtchenko in 1823. This may have been 

 based upon a report from natives and may indicate con- 

 ditions some time before 1823. It is, therefore, im- 

 possible to say exactly when the re-advance of the 

 glaciers took place. 



