54 TARR AND MARTIN CHANGES OF LEVEL IN YAKUTAT REGION 



amount in a short distance. There are also ancient, forest-covered beaches 

 on Krutoi and Otmeloi islands. 



Near the head of Russell fiord there are elevated shorelines about 140 

 feet above the fiord; but these are believed to be associated with a lake 

 dammed by an ice barrier in lower Russell fiord and Disenchantment bay 

 during a recent advance of the glaciers. 



Repeated traverses failed to reveal evidence of higher stands of the sea 

 at levels above those described; but it is to be noted that former greater 

 extension of the glaciers is proved for this region. We have evidence that 

 Hubbard glacier reached down to Haenke island a century ago, and the 

 evidence is clear that all of Nunatak fiord and more than half of Russell 

 fiord have only recently been abandoned by the ice. At an earlier period, 

 but at no very remote time, the entire inlet, clear to the ocean, was occu- 

 pied by ice. These facts would help to explain the absence of higher 

 shorelines if this deformation has long been in progress. 



EVIDENCE OF OLDER DEPRESSIONS 



At the head of Russell fiord and at Logan beach (plate 22, figure 2), 

 on the east shore of Yakutat bay, submerged forests appear on the beach 

 between tides. In both cases they occur in places where evidence of uplift 

 in 1899 is absent, and close by, and on the downthrow side of, fault lines 

 inferred from the evidence of the deformed shorelines. In each case evi- 

 dence of depression in 1899 is found not far away; but the submerged 

 forest at the head of Russell fiord was discovered by Russell in 1891, and 

 therefore this submergence antedates the 1899 deformation. 



Statement of Quantitative Observations 



METHODS EMPLOYED 



Along a coastline upward of 150 miles in length we examined almost 

 every part carefully and selected over one hundred points as suitable 

 places for quantitative measurements. Our method of measuring the 

 change of level necessarily varied with conditions; but wherever possible 

 our measurement is the vertical distance between the highest living and 

 the highest fixed dead barnacles, in a place where the latter are well pre- 

 served. For obtaining these measurements we used the Locke level and 

 a graduated rod, the greatest elevations being checked by aneroid. 



This method, like any other we could devise, was subject to a small 

 error; but, owing to the widespread abundance and excellent preservation 

 of the barnacles on the elevated shoreline, the amount of this error could 

 not be great. Care was taken to select the most favorable sites, and very 



