STRIKE FIORDS 
153 
in close association exhibit a systematic northwest trend; 
these are Icy Strait, Freshwater Bay, the main part of 
Tenakee Inlet, and Peril Strait with its prolongation in 
Hoonah Sound. The divergence of the branching fiords 
at the head of Lynn Canal is also perplexing; for, while 
each of these is so straight as to suggest an origin con¬ 
nected with strike, they are not parallel, but diverge fan- 
wise from a common point. 
The walls of Lynn Canal are well-defined features. At 
the water’s edge and for some distance above, their con¬ 
tours are simple. There are few bays and no jutting prom¬ 
ontories. The slope of the walls is not so steep as in 
some fiords; it rarely exceeds 45°, and in places is as low 
as 30°. Near the head of the canal the walls are well 
defined up to an altitude of about 2,000 feet, the height 
increasing toward the north and decreasing toward the 
south. Higher up, the mountains exhibit a varied topog¬ 
raphy: There 
are U-shaped 
troughs end¬ 
ing as hang¬ 
ing valleys at 
many differ¬ 
ent heights; 
there are V- 
shaped gorges 
modified at 
bottom by 
glaciers and 
separated by 
narrow tenti- 
FIG. 76. HANGING GLACIER, TAIYA INLET. 
The sill of the hanging valley is 3,500 feet above sea-level. For 
more than 1,000 feet below the glacier the fiord wall is kept bare by 
falling fragments of ice. 
form spurs. These troughs, gorges and spurs approach 
the canal wall at all angles and there end. Some¬ 
times they end abruptly, sometimes with a certain amount 
of prolongation down the steep wall; but this prolon- 
