204 GENERAL GEOLOGY 



1909. 



Jan. 2. Coast Lake all melted but a small patch. (lu Blue and Clear Lake.s found pools frozen.) 



Jan. 18. Coast Lake and Green Lake all melted. 



Feb. 2. Green Lake all frozen except hole 2 yards across in centre. 



Feb. 24. All lakes frozen, ice thick (1 foot or more in Coast Lake). 



Dec. 1 to 4. Maximum thaw on land. Snow gone from all Cape Royds District except little 

 drifts at north side of peaks and ridges. Thaw-water from drift behind hut, 

 flooded beneath hut (2nd December). Small streams running in all valleys, and 

 their channels gieen all over with algae. 



DrygalsU-Nansen Region. Little evidence of much work being accomplished 

 by thaw-water was observed by us in this area. On December 22, 1908, we found 

 a pool of thaw-water on the surface of the ice, fed by a subglacial stream coming 

 from an old rock moraine on the piedmont about 2 miles off the coast. On 

 December 22, 23, and 24 a thaw-water stream could be heard roaring alonw under 

 the snow and glacier ice of Backstairs Passage, next to the northern granite cliff of 

 Mount Crummer. This was evidently flowing at the bottom of the snow-filled fosse 

 at the base of the cliff". This thaw-water formed a shallow lake about half a 

 mile by a quarter of a mile over the surface of the old sea ice at the foot of the 

 glacier. At this time avalanches were de.scending from time to time from Mount 

 Crummer. At the south side of the Drygalski Ice Barrier Tongue, at the point 

 where our route reached its farthest point east, we observed a glacial torrent 

 channel entering a kind of e.stuary, or inlet, in the Barrier. The inlet was about 

 half a mile in length, and then passed into a narrow torrent channel 10 to 20 

 yards wide and about 20 to 30 feet deep. The channel was cut chiefly out of drift 

 snow, partly out of ice. The following is a sketch plan of this thaw-water 

 channel (Fig. 59). 



A curious and very beautiful etching effect was observed on the Larsen Glacier 

 portion of the Drygalski-Reeves Piedmont on January 31 and February 1,1909. The 

 surface of the piedmont was found to be covered with curved anastomosing plates 

 of thin ice, dipping at angles of approximately 30° or so, and on the whole, while 

 the direction of dip varied, showing a general tendency to dip away from the north 

 towards the south. 



Sledging over these inclined thin sheets of ice might be compared to tramping 

 over a wilderness of cucumber frames inclined at the above angle, the ice plates 

 sometimes supporting one's weight, sometimes giving way with a crash, and letting 

 one through up to one's thighs on to the surface of the solid ice below. Our 

 colleague Murray's explanation of a somewhat similar structure probably applies to 

 this region also : * — 



"In the height of summer the combined action of the sun and air on compacted 



• Heart of the Antarctic, vol. ii. p. 341. 



