Page:Quarterly Journal of the Geological Society of London, vol. 33.djvu/192

154 154 AHTJND HELLAND ON THE FJORDS, LAKES,

of the ice-sheet. Prom Kaiser Franz-Josefs Fjord on the east coast to that of Upernivik on the west is a distance of about 890 kilo- metres. If, then, a mass of ice, starting halfway, moved through the whole distance to Jakobshavn glacier at the rate of 15 metres a day, 29,666 days, or above 81 years, would elapse before it reached the fjord ; and it is not at all improbable that the Inland Ice would not move with any thing like the velocity of the glaciers.

Many Greerdanders are of opinion that the glaciers are steadily increasing. Accordingly Dr. Rink, in his excellent work on Green- land, has given a map of the south side of Umanak Fjord, showing the extent of several glaciers in the year 1850, and recording their exact distance from the sea at that date. I visited six of these, and compared their distances with those given by Dr. Rink. In the case of three I observed variations, one of which was considerable.

The glacier of Assakak is recorded by Dr. Rink to have been, in 1850, 400 ells (251 metres) from the sea ; in 1875 its end was so covered with stones that in some places we could not decide whether we were standing on the glacier or the moraine ; but it was nowhere nearer to the sea than 500 metres, so that in 25 years it has retreated about 250 metres. This glacier is interesting on account of the fossil stems of trees which it brings down. I followed them as they lay in a long row on the glacier for about one geographical mile to a height of 620 metres. If followed further they would, I think, lead to a site rich in fossil plants in the inner part of the Nugssuak peninsula.

The glacier of Umiatorfik, according to Dr. Rink, was from 600 to 800 ells (372 to 502 metres) from the sea ; its distance in 1875 was 322 metres, so that this one seems to have advanced.

The glacier of Sorkak is a most remarkable example of variation in a comparatively short lapse of time. Dr. Rink states that in 1850 the end was quite concealed by gravel and stones, and the ice only showed itself several hundred ells from the sea, on the site of an old homestead. When I visited this glacier in 1875 it had advanced out into the sea and ended in an ice- wall about 25 metres high. Near to its extremity it seemed to be about double that thickness. Dr. Rink also states that the Greenlandcrs told him that this glacier formerly entered the sea and cracked the ice of the fjord when it " calved " in winter ; so that in the course of two generations this glacier has receded and advanced several hundred ells ; hence along the south side of Umanak Fjord the glaciers do not prove a uniform increase of ice in North Greenland.

Icebergs and tlieir formation. — The forms of icebergs are very variable ; but as these have been so often described we need not enter into details. Their surface is usually clean, but now and then one is seen with boulders upon it, and here and there little bergs occur quite covered with stones and gravel." The profile of an ice-fjord (fig. 2, p. 152) will illustrate the formation of bergs, a process which has been often explained, and so need not detain us. I have twice witnessed the formation of a berg — once in Jakobshavn Fjord, once in Torsukatak Fjord. The glacier in the former " calved "