Smithsonian Report. I''50. Black 



Plate 9 



1. Caving polygons near Barrow, with relief of 4 to S feet, resulting from the 

 thawing of ice wedges after the protecting mat of tundra vegetation has been 

 removed. Photographed August 25, 11)47. 



(Iround ice in foundation excavation near Barrow. Concri'tc in Imi.i. i.. 

 being heated to permit setting on top of permafrost. Photographed July 

 15, 1947. 



