Observations of Alpine glaciers during a series of years have supplied proof that these great ice streams have long been in process of recession. Similar evidence with regard to the Greenland glaciers has not been collected over a ide area, though Dr. M. C. Engell, of Copenhagen, who visited the Jakobshavn glacier last summer, has made a collection of facts which seems to show conclusively that the glaciers of Greenland are also receding.
Dr. Engell selected the Jakobshavn glacier for his studies because it is the only glacier of Greenland which has been observed by white visitors for a long period of time. At least nine visitors, several of them men of science, have examined these glaciers within the past fifty-three years. They did not all record the location of its front so clearly that Dr. Engell, in making his map, can be certain that he has correctly assigned the position of its face at the time each man saw it, but there seems to be little doubt that his map of the retreat of the Jakobshavn glacier just published in Petermann’s Mitteilungen is approximately correct.
Among the visitors to the glacier whose observations are shown on Dr. Engell’s map were Rink, Nordenskjold, and other well-known Arctic students. The map shows approximately the position of the front of the great glacier in 1850, 1875, 1879; March, 1880; August, 1880; February, 1893, August 1893; and 1902.
The information given on the map indicates that in the past fifty-three years the face of the glacier has retreated about eight miles. Not only is it shorter than it formerly was, but its mass has otherwise been reduced to a very considerable extent. The surface of the glacier now lies from 20 to 30 feet below its former level and the precipitous walls of rock that hem it in bear the record of this change of level. It is found also that the other glaciers in that neighborhood are in process of retreat, and the evidence collected by Dr. Engell shows that this process has been going on for a long series of years.
This evidence would seem to show that for the past half century the summer heat has been greater than it was for at least a considerable period before that time, with the result that on the whole the ice of south Greenland has been melting a little more rapidly than it was formed.
Source: Scientific American Supplement No. 1493