The Editor,
The Journal of Glaciology
Sir,
Since the last issue of the Journal of Glaciology was published, my attention has been drawn to Professor R. F. Flint’s excellent description of Sørbreen (South Glacier) of Jan Mayen in Miss Louise A. Boyd’s The Coast of Northeast Greenland. This detailed account was written in 1938 from observations made in the summer of 1937. I would like to point to two features mentioned in this, which I failed to observe in 1938. West of Sørbreen near its snout, Flint records a striated rock surface and other indications of early extension in that direction and also an old lateral moraine north of Kapp Fishburn (Cape Fishburn) east of the outer lateral moraine of my description. This evidence suggests that Serbreen also suffered the earlier phase of retreat that Kerckhoffbreen (Kerckhoff Glacier) and certain other glaciers underwent.
Lt. Bobrik von Boldva noticed the absence of any mention of Sørbreen in a seventeenth-century Dutch description of Jan Mayen. Flint recalls this and regards it as furnishing “a possible minimum time for the entire series of South Glacier deposits.” However, von Boldva shows how unreliable the Dutch accounts are with reference to other glaciers on the island. Moreover, William Scoresby, Jnr., failed to describe Sørbreen at the beginning of the nineteenth century. Thus this negative argument can hardly carry much weight.
It is of interest also to hear from Professor P. L. Mercanton, of the Commission helvétique des Glaciers, that he measured the rate of movement of Sørbreen in 1921 at 0.5 cm. a day. This slow speed agrees with the Austrian measurement in 1882 and the retreat phenomena of the glacier.
9 January 1949.
