150 GLACIOLOGY 



the Hut, and at the foot of the ridges from High Peak in a south-westerly direction. 

 It occupies a fairly shallow basin, completely surrounded, with one exception, by 

 high ground, and must receive the drainings from a relatively considerable area. 

 The one exception is a snow slope towards the sea, which connects with the lake 

 itself, and would serve as an emergency outlet if the thaw-water in summer caused 

 any sudden rise of the waters of the lake. 



To the north-east and north it is bounded by ridges which run back to a 

 knotting jjoint near the top of the High Peak, whilst to the east and south-east 

 the ridges and small hills stand some way back from the lake, being separated 

 from it by a very gradually shelving slope, 100 yards broad, of morainic gravel 

 of small sub-angular kenyte fi'agments with a sprinkling of larger boulders of 

 kenyte and foreign erratics, such as the silicified oolites which we suppose to 

 have analogy with some of the sedimentary rocks at the head of the Beardmore 

 Glacier. 



A very slight accession of water or ice to the lake would, if the outlet on the 

 seaward side were blocked up, cause the addition to the lake bed of a considerable 

 area of the shelving plain. 



To the south the lake is bordered by ridges running east and west, which end 

 near the sea in a hill of some size, which is marked on the map as Red Flag Hill. 

 On the shore side of this hill is a fairly large snow slope which, being sheltered 

 from the southerlies by the hill itself and on the north by High Hill and its ridges, 

 is one of the most permanent snow-drifts on the peninsula. 



On the west the lake is bounded by the sea, and is separated from it by the 

 snow slope already mentioned, and by ridges and knobs of kenyte, which again end 

 in a small rounded hill of a very typical shape. On this side of the lake are two 

 large erratics, one of aplite and one of grey granite. 



The lake itself is between 90 and 100 yards in greatest length from north to 

 south, whilst its breadth varies from 100 yards to 45 yards. Its surface is smooth, 

 even glassy, and is traversed in winter by numerous contraction cracks due to the 

 great cold. These ci*acks after a spell of comparatively warm weather have been 

 observed to become appreciably smaller, and in summer many of them closed al- 

 together and were recemented by regelation in some cases, and in other cases, where 

 the expansion of ice did not quite cause them to join up, by thaw-water from the 

 sides of the crack. Tlie space between the sides of the cracks might also be reduced 

 through the addition of thin layers of ice formed by the freezing of aqueous vapour 

 on the walls of the crack. 



On one occasion whilst we were working on the lake we were surprised by a 

 series of reports like pistol-shots and by the appearance of cracks, and the cause 

 was explained when we returned home. After inquiring of the meteorologist we 

 found that the temperature had drojaped from -3° F. to -21° F. in considerably 

 less than two hours, so that the cracks were obviously contraction cracks. 



