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PLATE LXXXII. TIDE-CRACKS AND SHORE-ICE. 



FIG. 1. From a photograph by E. H. SHACKLETON (Sh. 148, - plate), Sept. 9, 1902. 



FIG. 2. From a photograph by C. R. ROYDS (R. 118, 5" x 4" film), Feb. 1902; 

 showing Hut Point as it appeared soon after our arrival, and before the sea 

 became frozen over. 



In Fig. 1 the small crack known as the " tide-crack " is seen along the lower 

 edge of the shore ice-cliff, dividing it from the sea-ice. It is a rare thing to find 

 this crack obliterated by a snow-drift, or even temporarily masked, so long as the 

 thickness of the floating ice is not excessive. The whole angle between the land- 

 ice cliff and the sea-ice may be filled with a sloping snow-drift 200 or more feet 

 high ; but even so, the crack will be found somewhere along the slope of the drift, 

 very small perhaps, but still visible, and possibly very high up instead of at the level 

 of the sea-ice. Only when the slope of snow-drift extends for miles from land upon 

 a true Barrier ice-sheet is it hard to find where the line of movement lies, and 

 impossible often to find a crack ; as, for example, at certain places along the S. side 

 of Erebus Island. The water running from the ice-face in Fig. 2 is not an 

 indication of melting in the land-ice, but merely the drip from the wash of a 

 wave which has recently swept along it. (See Plates XXVIII. and LXXXI.) 



