SCIENTIFIC RESULTS 



91 



4 feet per day. Many of the great Greenland glaciers, in other 

 words, move ten to fifteen times faster than those in the Alps. 

 About four times a month during the summer, usually accompanying 

 spring tides, 800 to 1,000 feet of the fjord end break off in great 

 calvings: Drygalski (1895, p. 401) estimates that the output of 

 Great Karajak is approximately 15.3 cubic kilometers per year, and 

 we have estimated the annual number of sizable bergs calved as ap- 

 [jroximately 1.200. This figure is believed to be conservative, but, 

 of course, somewhat speculative although it can be hardly over 25 per 

 cent in error. 



JACOBSHAVX FJORD AND GLACIER 



Jacobshavn is one of the best known and interesting of all Green- 

 land's glaciers. The Marlon^ in August, 1928, cruised in amongst the 



Jacobshavn Glacier 



Figure 51. — Jacobshavn Glacier, locateil on the west coast of Greenland, is estimated 

 to discharge annually 1,350 sizable icebergs info Disko Bay. It is one of the most 

 productive iceberg glaciers in the world. The position of the front wall is shown 

 from 1850 to 1902. Recent observations indicate a general retreat of many of the 

 glaciers in this section of Greenland. (After Hammer and Engell.) 



bergs that clogged the mouth of the fjord: as those within were 

 joined so closel}^ together that not even a ship's boat could pass be- 

 tween them. We had another view of these l^ergs when we landed 

 at Jacobshavn and crossed the hills to look down from a height into 

 the fjord itself. Jacobshavn Fjord is a more or less straight trough- 

 like depression, possibly a rift valley, 3 to 4 miles in width and 

 extending inland a distance of 15 miles where it meets the high front 

 of the glacier. As far as the eye could see in the fjord icebergs 

 were |)acked tightly row upon row, a majestic ])rocession marching 

 toward the open sea. It is estimated that on August 9, 1928, 4,000 

 to 6.000 bergs, 3 or 4 years supply, perhaps more, which had calved 

 from the glacier front, lay in the Jacobshavn Fjord. 



At uncertain intervals, approximately ten times a year, and with- 

 out warning, so say the natives, this iceberg train moves. It starts 



