48 TARE AND MARTIN CHANGES OF LEVEL IN YAKUT AT REGION 



abundant than normal, and without any evident association with pecu- 

 liarly favorable rock conditions. Moreover, they reach their best develop- 

 ment in sections where other evidence suggests the neighborhood of a fault- 

 line to a steep mountain slope. The most abundant avalanches, far 

 exceeding in number any seen in equal area either on the 1,000-mile trip 

 up the Inside passage or elsewhere in the Yakutat Bay region, occur along 

 the mountain front near Knight island, and thence northward along the 

 mountainous shore of the east side of Yakutat bay to point Latouche. 

 The Indians report that "the mountain face was here entirely changed in 

 1899 ;" and the vast extent of avalanches, involving hundreds of thou- 

 sands of tons of rock, leads one to accept this statement as, in general, 

 accurate. 



Along the shores of Disenchantment bay, also in a region of inferred 

 faulting, there is an excess of avalanches; but the absence of forest here 

 makes their presence less clear and striking. We fortunately have a 

 photograph taken here in 1890 by Eussell, looking into the valley of the 

 Black glacier 4 or 5 miles south of the Turner glacier, and at the point 

 where, within a mile and a half, there is a change from a shoreline with no 

 uplift to one uplifted 42 feet. A comparison of this photograph with the 

 condition in 1905 shows remarkable changes, far in excess of what would 

 be expected from normal weathering in 15 years. Great areas of alder 

 and grass-covered slopes have disappeared ; talus slopes are noticeably 

 enlarged; and the mountain face is materially altered in detail. 



In marked contrast is the series of hanging glaciers, not far away, 

 south of the Turner glacier, delicately poised on the precipitous moun- 

 tain side 1,000 feet or more above a shore which was uplifted 33 to 47 

 feet, none of which fell in 1899. One of these did slide out of its valley, 

 however, while we were in the bay in 1905. This indicates moderate 

 disturbance at points away from the actual fault lines. 



WAVE-SWEPT AREAS 



That earthquake water waves were generated by the shocks of 1899 is 

 proved by the testimony of the natives, of the prospectors who were en- 

 camped near the Hubbard glacier, and of the white residents of Yakutat. 

 Throughout most of the inlet no evidence of destruction by these waves is 

 found ; yet in places the evidence t>f a destructive water wave is very clear. 

 Parts of the shores of the fiord are unfavorable to the preservation of 

 records of such waves, but many sections are very favorable and yet show 

 no evidence of an earthquake wave. For example, the low, wooded shores 

 of Knight island show little or no signs of disturbance by the earthquake 



